Seismic Performance and Optimization of a Novel Partial Seismic Isolation System for Frame Structures

Baokui Chen; Yuxin Qiu; Jingang Xiong; Yaru Liu; Yanqing Xu

doi:10.3390/buildings12070876

Chen, Baokui;Qiu, Yuxin;Xiong, Jingang;Liu, Yaru;Xu, Yanqing

2022-06-22 00:00:00

buildings Article Seismic Performance and Optimization of a Novel Partial Seismic Isolation System for Frame Structures Baokui Chen, Yuxin Qiu, Jingang Xiong *, Yaru Liu and Yanqing Xu School of infrastructure Engineering, Nanchang University, Nanchang 330031, China; bkchen@ncu.edu.cn (B.C.); 416000210055@email.ncu.edu.cn (Y.Q.); 411114619033@ncu.edu.cn (Y.L.); xuyanqing@ncu.edu.cn (Y.X.) * Correspondence: xiongjingang@ncu.edu.cn Abstract: To improve the safety performance of important rooms, such as operating rooms and disaster command centers, during an earthquake, a novel partial seismic isolation system suitable for new and existing frame structures is proposed, and the seismic and optimization analysis is carried out. Using the finite element numerical simulation method, the models of the ordinary frame structure and the partial isolated system structures were established. Considering the seismic response of the isolation room, the design safety of the partial isolation room, and the seismic impact on the overall structure, this study analyzed the damping effect of the partial isolation system. We changed the type of isolation bearing, the location of the isolation room, and the load to further optimize the calculation of the seismic isolation structure. The results show that the new partial isolation system could significantly reduce the seismic response of the isolated room under the action of a magnitude-8 rare earthquake. The damping rate of the relative acceleration and relative displacement between the top and bottom of the columns of the isolated room could reach 90%. It was found that the partial seismic isolation system proposed in this paper was applicable to reinforced concrete frame structures and could significantly reduce the seismic response of the isolated rooms without affecting the seismic Citation: Chen, B.; Qiu, Y.; Xiong, J.; performance of the main building. This partial seismic isolation system is easy to construct, applicable Liu, Y.; Xu, Y. Seismic Performance to both existing and new structures, and provides a new and effective seismic mitigation measure to and Optimization of a Novel Partial improve the seismic performance of locally important rooms in the structure. Seismic Isolation System for Frame Structures. Buildings 2022, 12, 876. Keywords: partial seismic isolation; frame structure; numerical simulation; seismic performance; https://doi.org/10.3390/ isolation bearing buildings12070876 Academic Editors: Chunxu Qu, Shibin Lin, Donghui Yang and Sadegh Shams 1. Introduction Received: 19 May 2022 Ensuring the safety of all equipment and personnel in some rooms with important Accepted: 19 June 2022 functions, such as the operating room, and not affecting the normal use function of the Published: 22 June 2022 room an under earthquake, is one of the important ﬁelds of seismic research for build- ing structures. Relevant specialists have presented some novel ideas and initiatives. Tan Publisher’s Note: MDPI stays neutral et al. [1] presented a partial seismic isolation system for masterservant coupled structures, with regard to jurisdictional claims in published maps and institutional afﬁl- in which a seismic isolation layer is only installed in the servant structure and the servant iations. structure is sacriﬁced during strong earthquakes to protect the master structure’s safety. Morales et al. [2] presented a new low-cost seismic protection system that uses recycled automobile rubber tires to isolate certain rooms or equipment in buildings in order to mini- mize the dynamic response and to enhance structural and member performance. However, Copyright: © 2022 by the authors. complex evaluation of the tire’s characteristics is required before the seismic protection Licensee MDPI, Basel, Switzerland. system can be implemented and deployed in critical health care facilities. Losanno et al. [3] This article is an open access article investigated the use of recycled rubber by focusing on modeling aspects [4] and aging ef- distributed under the terms and fects [5], and developed a sustainable foundation isolation system based on a new low-cost conditions of the Creative Commons isolator. The results show that the device can effectively reduce the structure’s absolute Attribution (CC BY) license (https:// acceleration and base shear, indicating that this low-cost isolation device has the potential creativecommons.org/licenses/by/ to reduce earthquake risk in developing countries. Baggio et al. [6] investigated a double 4.0/). Buildings 2022, 12, 876. https://doi.org/10.3390/buildings12070876 https://www.mdpi.com/journal/buildings Buildings 2022, 12, 876 2 of 16 concave curved surface slider (DCCSS) seismic isolation device for sculptural seismic protection and evaluated the effectiveness of this isolation system using nonlinear dynamic analysis. On the contrary, Pellecchia et al. [7,8] proposed the use of elastomeric bearings to protect art-objects from earthquake-induced vibrations in order to contribute addressing similar issues in the challenging task of protecting cultural heritage from earthquake dam- age. Mezghani et al. [9] improved the metallic dampers to offer a higher performance to protect sensitive equipment under moderately strong or strong earthquakes, then proposed the wire mesh vibration damper (WMVD) for vibration-sensitive equipment. The results revealed that the WMVD isolated system can effectively attenuate a seismic response of more than 85%. Meanwhile, ﬂoor isolation systems have been becoming increasingly popular as a protective measure for nonstructural components. Jia et al. [10] optimized the ﬂoor isolation system based on the reliability criterion to maximize the probability that the acceleration response of the protected equipment would not exceed the acceptable performance limit. In addition, global sensitivity analysis based on samples was integrated to study the importance of different risk factors regarding system failure probability. Theoretical and experimental research on seismically isolated buildings has received increased attention in recent years, and related research has become increasingly com- prehensive [11–17]. To strengthen a medical building, Ye et al. [18] used three seismic isolation schemes: foundation isolation, additional ﬂexural restraint bracing, and addi- tional sway walls. They discovered that the seismic isolation scheme could reduce both the displacement and absolute acceleration responses of the structure, which has obvi- ous beneﬁts in reducing the economic losses from earthquakes. Murota et al. [19] used numerical and experimental methods to explore the suitability of high damping rubber bearings in the seismic isolation of residential buildings in Turkey, evaluating the seismic response of the buildings and determining the efﬁcacy of the seismic isolation system. Sung et al. [20] proposed incorporating an elliptical member equipped with a rubber cylinder in a portal reinforced concrete frame and conducted shaking table tests, which showed that the proposed strengthening method could not only restore the seismic capacity, but also improve the seismic resistance of the reinforced concrete frame damaged by the earthquake. Zheng et al. [21] created a scaled-down model of a four-story frame structure with friction pendulum support for seismic isolation and conducted shaking table tests, which revealed that the friction pendulum can signiﬁcantly reduce inter-ﬂoor displacement and ﬂoor accel- eration, as well as provide good seismic isolation. Xu et al. [22] suggested an SMA-based self-resetting bracket, and the ﬁnite element analysis revealed that the bracket with a super elastic SMA bolted connection has a strong self-resetting capability, and can signiﬁcantly reduce the residual deformation of the structure after the seismic response. Yang et al. [23] constructed a theoretical mechanical model of an oblique rotating three-dimensional seis- mic isolation device, and conducted static tests and numerical simulation studies on it, concluding that the bearing can guarantee the bearing capacity with vertical displacement and can achieve the vertical energy dissipation seismic isolation goal. Isolation systems mainly rely on energy dissipation mechanisms, usually using the concept of viscous damp- ing to evaluate these energy dissipation mechanisms. Li et al. [24] studied the equivalent problem of friction and viscous damping of a spring friction pendulum vibration isolation system under sine wave ground motion, providing a new method for unifying the concept of damping and evaluating the amount of damping in structures. Although both base and ﬂoor seismic isolation techniques are established for new structures [25–30], overall seismic isolation is costly [31] and difﬁcult to apply to existing structures. For operating rooms and other local functional rooms with special damping requirements, it is of great signiﬁcance to reduce the seismic response of local rooms and to ensure equipment and personnel work sustainably in the room after an earthquake or even at the epicenter. At present, there is research on partial isolation considering a ﬂoor isolation system [32], but it mainly focuses on the isolation of equipment. This can only ensure the equipment is intact, but it cannot protect other ancillary components, and cannot guarantee the continuity and safety of important work such as surgery in earthquakes. Therefore, Buildings 2022, 12, x FOR PEER REVIEW 3 of 17 isolation system [32], but it mainly focuses on the isolation of equipment. This can only ensure the equipment is intact, but it cannot protect other ancillary components, and can- not guarantee the continuity and safety of important work such as surgery in earthquakes. Therefore, a novel partial seismic isolation structural system based on foundation seismic isolation is proposed, which could not only play an isolation and damping role for im- portant equipment, but could also ensure the safety of equipment and non-structural com- ponents of the whole room, so that the functional room can maintain its complete func- tionality during and after an earthquake. This isolation system can be used for partial seismic isolation retrofit of rooms that require key fortification, such as operating rooms Buildings 2022, 12, 876 3 of 16 and intensive care units. In order to determine the effectiveness and safety of the proposed local seismic isolation system, through finite element numerical simulation technology, this paper systematically analyzes the seismic reduction effect and safety of the new iso- a novel partial seismic isolation structural system based on foundation seismic isolation lation system, as well as the impact on the overall structural seismic performance. The is proposed, which could not only play an isolation and damping role for important equipment, but could also ensure the safety of equipment and non-structural components new system proposed in the study can not only reduce the seismic response of the local of the whole room, so that the functional room can maintain its complete functionality structure, but through optimization analysis, it can also gradually form a local seismic during and after an earthquake. This isolation system can be used for partial seismic isolation design method applicable to different functional objectives. The research results isolation retroﬁt of rooms that require key fortiﬁcation, such as operating rooms and intensive care units. In order to determine the effectiveness and safety of the proposed will expand the ideas of the research on the seismic performance of local structures and local seismic isolation system, through ﬁnite element numerical simulation technology, this will propose an innovative design method for local structure seismic reduction, which has paper systematically analyzes the seismic reduction effect and safety of the new isolation important research significance and engineering value. system, as well as the impact on the overall structural seismic performance. The new system proposed in the study can not only reduce the seismic response of the local structure, but through optimization analysis, it can also gradually form a local seismic isolation design 2. Partial Seismic Isolation System and Numerical Model method applicable to different functional objectives. The research results will expand the 2.1ideas . Partial Seismic Isolation of the research on the seismic System performance of local structures and will propose an innovative design method for local structure seismic reduction, which has important This study proposes a partial seismic isolation system based on the foundation isola- research signiﬁcance and engineering value. tion for both existing and new frame structures, as shown in Figure 1. The partial seismic 2. Partial Seismic Isolation System and Numerical Model isolation system is composed of structural columns, upper and lower ring beams, floor 2.1. Partial Seismic Isolation System slabs, and maintenance members, which is connected to the main beam of the frame struc- This study proposes a partial seismic isolation system based on the foundation isola- ture through an isolation bearing. Furthermore, the isolation joints between two sides and tion for both existing and new frame structures, as shown in Figure 1. The partial seismic isolation system is composed of structural columns, upper and lower ring beams, ﬂoor adjacent columns are 200 mm. The seismic isolation bearing can be set at the position of slabs, and maintenance members, which is connected to the main beam of the frame struc- the frame structure’s main beam, and the partial seismic isolation system does not come ture through an isolation bearing. Furthermore, the isolation joints between two sides and into contact with the structural frame columns or the original structural floor slab, retain- adjacent columns are 200 mm. The seismic isolation bearing can be set at the position of the frame structure’s main beam, and the partial seismic isolation system does not come into ing a suitable safety distance. contact with the structural frame columns or the original structural ﬂoor slab, retaining a suitable safety distance. Figure 1. Novel partial seismic isolation structure diagram. Figure 1. Novel partial seismic isolation structure diagram. The partial seismic isolation system achieves a ﬂexible connection in the horizontal di- rection between the original frame beam and the partial room through the seismic isolation The partial seismic isolation system achieves a flexible connection in the horizontal bearing. The seismic energy transferred to the partial isolation room is signiﬁcantly reduced direction between the original frame beam and the partial room through the seismic iso- and changes the dynamic characteristics of the room to approximate whole translation lation bearing. The seismic energy transferred to the partial isolation room is significantly motion, thereby reducing the seismic response of the partial room [33]. This is because under the action of an earthquake, the bearing consumes energy because of the hysteretic reduced and changes the dynamic characteristics of the room to approximate whole trans- behavior, so that the energy transmitted to the isolated room is signiﬁcantly reduced, thus lation motion, thereby reducing the seismic response of the partial room [33]. This is be- leaving it in a whole translation motion. As shown in Figure 2, this study analyzes the cause under the action of an earthquake, the bearing consumes energy because of the hys- performance and effect of the partial seismic isolation system by comparing the seismic rtereti esponse c beha of the vior, originalso tha structur t the en e and theergy tra partial isolation nsmistr tted to the isola ucture. ted room is significantly re- duced, thus leaving it in a whole translation motion. As shown in Figure 2, this study analyzes the performance and effect of the partial seismic isolation system by comparing the seismic response of the original structure and the partial isolation structure. Buildings 2022, 12, x FOR PEER REVIEW 4 of 17 Buildings 2022, 12, 876 4 of 16 Buildings 2022, 12, x FOR PEER REVIEW 4 of 17 (a) original structure. (b) partial isolation structure. (a) original structure. (b) partial isolation structure. Figure 2. Response of structures under earthquake. Figure 2. Response of structures under earthquake. Figure 2. Response of structures under earthquake. 2.2. Numerical Model 2.2. Numerical Model 2.2. Numerical Model In order to reduce the interference of building construction and other factors on the In order to reduce the interference of building construction and other factors on the seismic response of the partial seismic isolation system, the study takes a four-story frame In order to reduce the interference of building construction and other factors on the seismic response of the partial seismic isolation system, the study takes a four-story frame structure with relatively simple construction as the research object and discusses the seis- seismic response of the partial seismic isolation system, the study takes a four-story frame structure with relatively simple construction as the research object and discusses the seismic mic reduction effect of the partial seismic isolation system. structure with relatively simple construction as the research object and discusses the seis- reduction effect of the partial seismic isolation system. The numerical model was established using finite element analysis software mic reduction effect of the partial seismic isolation system. The numerical model was established using ﬁnite element analysis software SAP2000, SAP2000, and the original concrete frame structure model is shown in Figure 3. At the and the original concrete frame structure model is shown in Figure 3. At the same time, a The numerical model was established using finite element analysis software same time, a frame model using the novel partial seismic isolation system was established, frame model using the novel partial seismic isolation system was established, in which the SAP2000, and the original concrete frame structure model is shown in Figure 3. At the in which the seismic isolation room was set in the middle of the second floor, and the rest seismic isolation room was set in the middle of the second ﬂoor, and the rest of the structure same time, a frame model using the novel partial seismic isolation system was established, of the structure was the same as the original structure. The basic layout of the building was the same as the original structure. The basic layout of the building was as follows: there in which the seismic isolation room was set in the middle of the second floor, and the rest was as follows: there were five spans in the X-direction with a span of 6 m and three spans were ﬁve spans in the X-direction with a span of 6 m and three spans in the Y-direction with of the structure was the same as the original structure. The basic layout of the building in the Y-direction with a span of 4 m. The structure had four floors and the height of each a span of 4 m. The structure had four ﬂoors and the height of each ﬂoor was 3.6 m. The floor w was asa fol s 3l.6 ow m. The cros s: there were s-sect fiiona ve sp l d ans ime in nsions the X of t -dih rect e column ion wit s we h a re 7 span 00 mm of 6 m × 70 and 0 mm, three spans cross-sectional dimensions of the columns were 700 mm 700 mm, the main beam was the main beam was arranged in an X-direction with a cross-sectional dimension of 300 in the Y-direction with a span of 4 m. The structure had four floors and the height of each arranged in an X-direction with a cross-sectional dimension of 300 mm 700 mm, and the mm × 700 mm, and the secondary beam was arranged in a Y-direction with a cross-sec- floor was 3.6 m. The cross-sectional dimensions of the columns were 700 mm × 700 mm, secondary beam was arranged in a Y-direction with a cross-sectional dimension of 300 mm tional dimension of 300 mm × 600 mm. The concrete compressive strength of the beams 600 mm. The concrete compressive strength of the beams and columns was 30 MPa, and the main beam was arranged in an X-direction with a cross-sectional dimension of 300 and columns was 30 MPa, and the yield strength of longitudinal ribs and stirrup were 335 the yield strength of longitudinal ribs and stirrup were 335 MPa and 300 MPa respectively. mm × 700 mm, and the secondary beam was arranged in a Y-direction with a cross-sec- MPa and 300 MPa respectively. The constant 2 load of the floor was 3 kN/m2 and the live The constant load of the ﬂoor was 3 kN/m and the live load was 2 kN/m . The seismic tional dimension of 300 mm × 600 mm. The concrete compressive strength of the beams load was 2 kN/m . The seismic precautionary intensity of the structure was magnitude 8, precautionary intensity of the structure was magnitude 8, and the corresponding design and columns was 30 MPa, and the yield strength of longitudinal ribs and stirrup were 335 and the corresponding design basic acceleration of the ground motion was 0.2 g. The basic acceleration of the ground motion was 0.2 g. The beamcolumn units in the frame MPa and 300 MPa respectively. The constant load of the floor was 3 kN/m and the live beam−column units in the frame structure were input according to the corresponding structure were input according to the corresponding frame section and material properties, load was 2 kN/m . The seismic precautionary intensity of the structure was magnitude 8, frame section and material properties, and the beam−column nodes were set as rigid junc- and the beamcolumn nodes were set as rigid junctions; the ﬂoor slab was input using and the corresponding design basic acceleration of the ground motion was 0.2 g. The tions; the floor slab was input using shell units and by specifying the partition bindings shell units and by specifying the partition bindings to achieve the assumption of the inﬁnite tbea o achieve m−co t lum he as n unit sumpt s iin t on of t he fr he in ame st finite in-p ructure were lane stiffness o input f th accord e floor sl in ab g t [3o4 t ]. he corresponding in-plane stiffness of the ﬂoor slab [34]. frame section and material properties, and the beam−column nodes were set as rigid junc- tions; the floor slab was input using shell units and by specifying the partition bindings to achieve the assumption of the infinite in-plane stiffness of the floor slab [34]. (a) Plan view (b) Elevation view Figure 3. Cont. (a) Plan view (b) Elevation view Buildings 2022, 12, x FOR PEER REVIEW 5 of 17 Buildings 2022, 12, 876 5 of 16 (c) Finite element model Figure 3. Layout drawing and finite element model of the original frame structure. Figure 3. Layout drawing and ﬁnite element model of the original frame structure. 2.3. Selection of Seismic Isolation Bearing 2.3. Selection of Seismic Isolation Bearing In this project, the partial isolation room was set on the main beam only through the In this project, the partial isolation room was set on the main beam only through the seismic isolation bearing, and the speciﬁc size of the bearing was determined by the reaction seismic isolation bearing, and the specific size of the bearing was determined by the reaction force at the bottom of each column and the bearing surface pressure under gravity load, force at the bottom of each column and the bearing surface pressure under gravity load, assuming that the main beam of the original structure had a sufﬁcient support capacity. assuming that the main beam of the original structure had a sufficient support capacity. The The relevant mechanical properties of the selected seismic isolation bearing are listed in relevant mechanical properties of the selected seismic isolation bearing are listed in Table 1. Table 1. Table 1. Basic parameters of the lead rubber bearing. Table 1. Basic parameters of the lead rubber bearing. Bearing Effective Diameter Total Rubber Thick- Pre-Yield Stiffness Equivalent Stiff- Vertical Stiffness Yield Force Effective Total Rubber Pre-Yield Equivalent Vertical Stiffness Yield Force Type (mm) Bearing Type ness (mm) (kN/m) ness (kN/m) (kN/mm) (kN) Diameter (mm) Thickness (mm) Stiffness (kN/m) Stiffness (kN/m) (kN/mm) (kN) LRB300 300 56 6440 760 1100 16 LRB300 300 56 6440 760 1100 16 The nonlinear hysteresis curve of the LRB isolation lead core rubber support could The nonlinear hysteresis curve of the LRB isolation lead core rubber support could be be simplified to the bilinear model shown in Figure 4 [35]. In Figure 4, the pre-yield stiff- simpliﬁed to the bilinear model shown in Figure 4 [35]. In Figure 4, the pre-yield stiffness ness Kb1, post-yield stiffness Kb2, and equivalent horizontal shear stiffness Keq of the seismic K , post-yield stiffness K , and equivalent horizontal shear stiffness K of the seismic eq isolation bearing were calc b1 ulated as follows. b2 isolation bearing were calculated as follows. 𝐾 = (1) 𝑋 y K = (1) b1 𝑄 −𝑄 (2) 𝐾 = Q Q b y 𝑋 −𝑋 K = (2) b2 X X b y 𝑄 −𝑄 Q Q b a (3) 𝐾 = K = (3) eq 𝑋 −𝑋 X X where X is the maximum horizontal positive displacement, X is the maximum horizontal where Xb is the maximum horizont b al positive displacement, Xa is the maximum horizont a al negative displacement, Q is the horizontal shear force corresponding to X , and Q is the negative displacement, Qb is the horizontal shear force correspondin b g to Xb, and Qa is the b horizontal shear force corresponding to X . horizontal shear force corresponding to Xa. a 2.4. Seismic Waves Considering the site category, fortiﬁcation intensity, and seismic wave selection prin- ciple of the model, the EL-Centro wave, Taft wave, and one artiﬁcial wave were selected. Selecting the appropriate peak ground acceleration (PGA) of seismic waves is a key step in structural seismic response analysis [36,37]. The seismic waves were taken as the horizontal bidirectional input, and the X-direction peak acceleration was adjusted to 400 gal (the magnitude 8 rare earthquake level in Chinses code [38]). The peak acceleration curves of the input were adjusted according to the ratio of X:Y = 1:0.85 [38], respectively. The adjusted X-direction acceleration time history of the seismic wave is shown in Figure 5. The comparison of the seismic response spectrum and standard response spectrum is shown in Figure 6. The empirical response spectrum of the seismic record is consistent with the Buildings 2022, 12, x FOR PEER REVIEW 6 of 17 Buildings 2022, 12, x FOR PEER REVIEW 6 of 17 Buildings 2022, 12, 876 6 of 16 Buildings 2022, 12, x FOR PEER REVIEW 6 of 17 Figure 4. Bilinear hysteretic model of the isolated bearing. Figure 4. Bilinear hysteretic model of the isolated bearing. statistical signiﬁcance of the normative response spectrum, so the selected seismic wave time curve met the selection requirements. 2.4. Seismic Waves 2.4. Seismic Waves Considering the site category, fortification intensity, and seismic wave selection prin- Considering the site category, fortification intensity, and seismic wave selection prin- ciple of the model, the EL-Centro wave, Taft wave, and one artificial wave were selected. ciple of the model, the EL-Centro wave, Taft wave, and one artificial wave were selected. Selecting the appropriate peak ground acceleration (PGA) of seismic waves is a key step Selecting the appropriate peak ground acceleration (PGA) of seismic waves is a key step in structural seismic response analysis [36,37]. The seismic waves were taken as the hori- in structural seismic response analysis [36,37]. The seismic waves were taken as the hori- zontal bidirectional input, and the X-direction peak acceleration was adjusted to 400 gal zontal bidirectional input, and the X-direction peak acceleration was adjusted to 400 gal (the magnitude 8 rare earthquake level in Chinses code [38]). The peak acceleration curves (the magnitude 8 rare earthquake level in Chinses code [38]). The peak acceleration curves of the input were adjusted according to the ratio of X:Y = 1:0.85 [38], respectively. The of the input were adjusted according to the ratio of X:Y = 1:0.85 [38], respectively. The adjusted X-direction acceleration time history of the seismic wave is shown in Figure 5. adjusted X-direction acceleration time history of the seismic wave is shown in Figure 5. The comparison of the seismic response spectrum and standard response spectrum is The comparison of the seismic response spectrum and standard response spectrum is shown in Figure 6. The empirical response spectrum of the seismic record is consistent shown in Figure 6. The empirical response spectrum of the seismic record is consistent with the statistical significance of the normative response spectrum, so the selected seis- with the statistical significance of the normative response spectrum, so the selected seis- mic wave time curve met the selection requirements. mi Figure 4. Figure c wa4. ve ti Bi Bilinear line me a curve met the sel r hy hyster steretic m etic model odel of the ecti of o the iso n req isolated lated bearing uirements. bearing. . 400 400 400 400 2.4. Seismic Waves 200 200 200 200 200 Considering the site category, fortification intensity, and seismic wave selection prin- 0 0 0 0 ciple of the model, the EL-Centro wave, Taft wave, and one artificial wave were selected. -200 -200 -200 -200 -200 -200 Selecting the appropri -400 ate peak ground acceleration (PGA) of seismic waves is a key step -400 -400 -400 -400 0 5 10 15 20 25 30 -400 0 5 10 15 20 25 30 0 5 10 15 20 25 30 0 5 10 15 20 25 30 0 5 10 15 20 25 30 0 5 10 15 20 25 30 in structural seismic response an Tim alys e (s)is [36,37]. The seismic waves were taken as the hori- Time (s) Time (s) Time (s) Time (s) Time (s) zontal bidirectional input, and the X-direction peak acceleration was adjusted to 400 gal (a) EL-Centro wave (b) Taft wave (c) Artificial wave (a) EL-Centro wave (b) Taft wave (c) Artificial wave (the magnitude 8 rare earthquake level in Chinses code [38]). The peak acceleration curves Figure 5. X−direction time−history curve of the seismic waves. Figure 5. X−direction time−history curve of the seismic waves. Figure 5. Xdirection timehistory curve of the seismic waves. of the input were adjusted according to the ratio of X:Y = 1:0.85 [38], respectively. The adjusted X-direction acceleration time history of the seismic wave is shown in Figure 5. 1.4 1.4 Standard response specturm Standard response specturm The comparison of the seismic response spectrum and standard response spectrum is EL-Centro wave EL-Centro wave 1.2 shown in Figure 6. The empirical response spectrum of the seismic record is consistent 1.2 Taft wave Taft wave with the statistical significance of the normative response spectrum, so the selected seis- Artificial wave 1.0 Artificial wave 1.0 mic wave time curve met the selection requirements. Average Average 0.8 0.8 400 400 0.6 200 0.6 0 0 0.4 0.4 -200 -200 -200 -400 -400 0.2 -400 0 5 10 15 20 25 30 0.2 0 5 10 15 20 25 30 0 5 10 15 20 25 30 Time (s) Time (s) Time (s) 0.0 0.0 (a) EL-Centro wave (b) Taft wave (c) Artificial wave 01234 56 01234 56 Period (s) Figure 5. X−direction timPer e−his iodt ( ory s) curve of the seismic waves. Figure 6. Comparison of the seismic response spectrum and standard response spectrum. Figure 6. Comparison of the seismic response spectrum and standard response spectrum. Figure 6. Comparison of the seismic response spectrum and standard response spectrum. 1.4 Standard response specturm EL-Centro wave 3. Analysis of Seismic Isolation Effect 1.2 Taft wave 3.1. Modal Analysis Artificial wave 1.0 The modal analysis can qualitatively determine the seismic response of the structure, Average 0.8 which is the basis for other dynamic analyses. The natural periods of the original structure and the partial isolation structure are detailed in Table 2. Table 3 shows the natural periods 0.6 of the isolated room in the partial isolated system. 0.4 Table 2. Modal analysis data of the structure. 0.2 Original Structure Isolated Structure Mode of 0.0 01234 56 Vibration Period (s) UX UY RZ Period (s) UX UY RZ Period (s) 1 0.413 0.820 0 0 0.413 0.798 0 0 2 0.383 0 0.826 0 0.384 0 0.804 0 Figure 6. Comparison of the seismic response spectrum and standard response spectrum. 3 0.340 0 0 0.830 0.340 0 0 0.825 4 0.124 0.118 0 0 0.133 0 0 0 5 0.117 0 0.116 0 0.132 0 0 0 Acceleration (gal) Acceleration (gal) Acceleration (gal) Seismic influence coefficient Seismic influence coefficient Seismic influence coefficient Acceleration (gal) Acceleration (gal) Acceleration (gal) Acceleration (gal) Acceleration (gal) Acceleration (gal) Buildings 2022, 12, 876 7 of 16 Table 3. Modal analysis data of the partial isolation room. Mode of Vibration Period (s) UX UY RZ 1 0.669 0 0.025 0 2 0.668 0.025 0 0 3 0.486 0 0 0.001 From Table 2, it can be seen that the vibration periods of the isolated structure and the original structure were almost the same, indicating that the partial isolation system did not affect the self-oscillation characteristics of the overall structure. UX, UY, and UZ were the mass participation ratios in the X, Y, and Z directions, respectively, of the vibration type, and the analysis shows that the ﬁrst order of the structure was whole translation motion in the X direction (UX + UY > UZ), the second order was whole translation motion in the Y direction, and the third order was a torsional vibration type around the Z axis (UX + UY < UZ). The ﬁrst three orders of the period of the partial isolation room were 0.669 s, 0.668 s, and 0.486 s, which were signiﬁcantly larger than the ﬁrst three orders of the self-oscillation period of the original structure, namely, 0.413 s, 0.380 s, and 0.340 s. The self-oscillation period of the partial isolation room was signiﬁcantly longer, which was conducive to avoiding the high frequency zone of seismic waves and greatly reducing the seismic energy transferred to the isolated room, thus improving the safety of the partial isolation room. 3.2. Dynamic Properties of Seismically Isolated Rooms The three selected seismic waves were input to each model and the dynamic history analysis under a magnitude 8 rare earthquake was carried out. It was found that the X-direction seismic response was larger compared with the Y-direction, so the envelope value of the X-direction response of the structure under the action of the three seismic waves was taken as a representative value for the nonlinear timehistory analysis. A reasonable evaluation index, the damping rate (D), was chosen to assess the damping effect of each seismic isolation structural model using the following equation: (REP REP ) ori iso D = 100% (4) REP ori where REP is the seismic response of the original structure and REP is the seismic ori iso response of the isolated structure. Figure 7 gives the relative acceleration and displacement time histories of the partial isolation room for the two structural systems under magnitude 8 rare earthquakes, i.e., the relative acceleration and relative displacement between the top and bottom of the columns of the isolated room. As shown in the ﬁgure, the seismic response of the room with a new partial isolation structural system is signiﬁcantly smaller than that of the original structure. The maximum values of the relative acceleration before and after seismic isolation were 2 2 4.98 m/s and 0.46 m/s , respectively, and the maximum values of relative displacement were 19.93 mm and 2.07 mm, respectively, which were calculated from Equation (4). The seismic isolation system changed the dynamic characteristics of the isolated room through the seismic isolation bearing. The isolated room showed the whole translation motion, and its seismic response was effectively reduced. 3.3. Hysteresis Performance of the Vibration Isolation Bearing The choice of seismic isolation bearing has an important inﬂuence on the seismic isolation effect. Figure 8 shows the hysteresis curve of the seismic isolation bearing. Under the effect of a magnitude 8 rare earthquake, the maximum horizontal displacement of the bearing was 53 mm. The bearing compressive stress was 1.27 MPa, which was much less than the speciﬁcation requirement. At the same time, the hysteresis ring of the bearing Buildings 2022, 12, x FOR PEER REVIEW 8 of 17 the relative acceleration and relative displacement between the top and bottom of the col- umns of the isolated room. As shown in the figure, the seismic response of the room with a new partial isolation structural system is significantly smaller than that of the original structure. The maximum values of the relative acceleration before and after seismic isola- 2 2 tion were 4.98 m/s and 0.46 m/s , respectively, and the maximum values of relative dis- placement were 19.93 mm and 2.07 mm, respectively, which were calculated from Equa- Buildings 2022, 12, x FOR PEER REVIEW 8 of 17 tion (4). The seismic isolation system changed the dynamic characteristics of the isolated room through the seismic isolation bearing. The isolated room showed the whole transla- tion motion, and its seismic response was effectively reduced. the relative acceleration and relative displacement between the top and bottom of the col- Original structure umns of the isolated room. As shown in the figure, the seismic response of the room with Original structure Isolation structure Isolation structure a new partial isolation structural system10 is significantly smaller than that of the original structure. The maximum values of the relative acceleration before and after seismic isola- -2 -10 2 2 Buildings 2022, 12, 876 8 of 16 tion were 4.98 m/s and 0.46 m/s , respectively, and the maximum values of relative dis- -4 -20 -6 placement were 19.93 mm and 2.07 mm, respectively, which were calculated from Equa- 0 4 8 12 16 20 24 28 32 0 4 8 121620 242832 tion (4). The seismic isolation system changed the dynamic characteristics of the isolated Time (s) Time (s) room through the seismic isolation bearing. The isolated room showed the whole transla- was full, indicating that the partial seismic isolation system had a good hysteresis energy tion motion, and its seismic response was effectively reduced. 2 dissipation performance. -2 Original structure -4 Original structure 20 4 -10 Isolation structure -6 Isolation structure -20 7.0 7.5 8.0 8.5 9.0 7.0 7.5 8.0 8.5 9.0 0 0 -2 -10 (a) Relative acceleration (b) Relative displacement -4 -20 -6 0 4 8 12 16 20 24 28 32 Figure 7. Damping effect of an isolated room. 0 4 8 121620 242832 Time (s) Time (s) 3.3. Hysteresis Performance of the Vibration Isolation Bearing The choice of seismic isolation bearing has an important influence on the seismic iso- lation effect. Figure 8 shows the hysteresis curve of the seismic isolation bearing. Under -2 0 -4 the effect of a magnitude 8 rare earthquake, the maximum horizontal displacement of the -10 -6 bearing was 53 mm. The bearing compressiv -20 e stress was 1.27 MPa, which was much less 7.0 7.5 8.0 8.5 9.0 7.0 7.5 8.0 8.5 9.0 than the specification requirement. At the same time, the hysteresis ring of the bearing (a) Relative acceleration (b) Relative displacement was full, indicating that the partial seismic isolation system had a good hysteresis energy Figure 7. Damping effect of an isolated room. dissipation performance. Figure 7. Damping effect of an isolated room. 3.3. Hysteresis Performance of the Vibration Isolation Bearing The choice of seismic isolation bearing has an important influence on the seismic iso- lation effect. Figure 8 shows the hysteresis curve of the seismic isolation bearing. Under the effect of a magnitude 8 rare earthquake, the maximum horizontal displacement of the bearing was 53 mm. The bearing compressive stress was 1.27 MPa, which was much less than the specification requirement. At the same time, the hysteresis ring of the bearing -20 was full, indicating that the partial seismic isolation system had a good hysteresis energy -40 dissipation performance. -60 -60 -45 -30 -15 0 15 30 45 60 Displacement (mm) Figure 8. Hysteretic curve of the isolated bearing. Figure 8. Hysteretic curve of the isolated bearing. 3.4. Safety of Partial Seismic Isolation Systems 3.4. Safety 0 of Partial Seismic Isolation Systems During the seismic response of the partial isolation rooms, collisions with the original During the seismic response of the partial isolation rooms, collisions with the original -20 structural frame columns should be avoided. Therefore, the study analysed the variation of structural frame columns should be avoided. Therefore, the study analysed the variation the distance between the structural columns of the partial isolation room and the adjacent -40 of the distance between the structural columns of the partial isolation room and the adja- frame columns under seismic loading, as a means of determining the safety of the structure. cent fr -60ame columns under seismic loading, as a means of determining the safety of the Figure 9 shows the displacement time curve between the frame column of the seismically -60 -45 -30 -15 0 15 30 45 60 structure. Figure 9 shows the displacement time curve between the frame column of the isolated room and Displace the menadjacent t (mm) members with an initial distance of 200 mm, which was the width of the reserved seismic isolation joint. Non-positive spacing means a collision Figure 8. Hysteretic curve of the isolated bearing. occurred. The minimum distance between the partial isolation room and the adjacent members was 167 mm under a rare earthquake of magnitude 8, indicating that no collision 3.4. Safety of Partial Seismic Isolation Systems would occur between the partial isolation room and the adjacent members, and that the During the seismic response of the partial isolation rooms, collisions with the original partial isolation structure had a high safety reserve. At the same time, the shear force structural frame columns should be avoided. Therefore, the study analysed the variation and bending moment of the beam below the bearing were calculated to be less than its of cr the di oss-sectional stance between the structural load carrying capacity. columns of the partial isolation room and the adja- cent frame columns under seismic loading, as a means of determining the safety of the 3.5. Effect of Partial Seismic Isolation on the Structure as a Whole structure. Figure 9 shows the displacement time curve between the frame column of the The seismic response of the original structure and the top of the partial isolation structure, as well as the inter-story displacement angles and shear forces, are shown in Figure 10 to Figure 11, respectively. Because of the small effect of the partial isolation system on the change in stiffness of the overall structure and the limited mass of the isolated rooms, by comparing the overall structural response of the two models, it was found that the use of partial seismic isolation or not had little effect on the overall seismic performance of the structure. The maximum inter-story displacement angle of the partial isolation structure Acceleration (m/s ) Acceleration (m/s ) ZOOM ZOOM Shearing force (kN) Shearing force (kN) Displacement (mm) Displacement (mm) ZOOM ZOOM Buildings 2022, 12, x FOR PEER REVIEW 9 of 17 seismically isolated room and the adjacent members with an initial distance of 200 mm, which was the width of the reserved seismic isolation joint. Non-positive spacing means a collision occurred. The minimum distance between the partial isolation room and the adjacent members was 167 mm under a rare earthquake of magnitude 8, indicating that no collision would occur between the partial isolation room and the adjacent members, and that the partial isolation structure had a high safety reserve. At the same time, the shear force and bending moment of the beam below the bearing were calculated to be less than its cross-sectional load carrying capacity. Buildings 2022, 12, x FOR PEER REVIEW 9 of 17 Initial distance seismically isolated room and the adjacent members with an initial distance of 200 mm, which was the width of the reserved seismic isolation joint. Non-positive spacing means Buildings 2022, 12, 876 9 of 16 a collision occurred. The minimum distance between the partial isolation room and the adjacent members was 167 mm under a rare earthquake of magnitude 8, indicating that 0 4 8 12 16 20 24 28 32 no collision would occur between the partial isolation room and the adjacent members, was 1/180 under a rare earthquake of magnitude 8, which still met the code requirement of and that the partial isolTim ation structure e (s) had a high safety reserve. At the same time, the 1/50 for the elasticplastic inter-story displacement angle under a rare earthquake. It was shear force and bending moment of the beam below the bearing were calculated to be less thus judged that the partial seismic isolation system had no effect on the seismic response Figure 9. Distance between the isolated room column and adjacent column. than its cross-sectional load carrying capacity. and stability of the overall frame structure. 3.5. Effect of Partial Seismic Isolation on the Structure as a Whole The seismic response of the original structure and the top of the partial isolation structure, as well as the inte Initial distance r-story displacement angles and shear forces, are shown in Figure 10 to Figure 11, respectively. Because of the small effect of the partial isolation sys- tem on the change in stiffness of the overall structure and the limited mass of the isolated rooms, by comparing the overall structural response of the two models, it was found that the use of partial seismic isolation or not had little effect on the overall seismic perfor- mance of the structure. The maximum inter-story displacement angle of the partial isola- tion structure was 1/180 under a rare earthquake of magnitude 8, which still met the code 0 4 8 12 16 20 24 28 32 requirement of 1/50 for the elastic−plastic inter-story displacement angle under a rare Time (s) earthquake. It was thus judged that the partial seismic isolation system had no effect on the seismic response and stability of the overall frame structure. Figure 9. Distance between the isolated room column and adjacent column. Figure 9. Distance between the isolated room column and adjacent column. 15 60 Original structure 3.5. Effect of Partial Seismic Isolation on the Structure as a Whole Original structure Isolation structure Isolation structure The seismic response of the original structure and the top of the partial isolation structure, as well as the inter-story displacement angles and shear forces, are shown in 0 0 Figure 10 to Figure 11, respectively. Because of the small effect of the partial isolation sys- -5 -30 tem on the change in stiffness of the overall structure and the limited mass of the isolated -10 rooms, by comparing the overall structural response of the two models, it was found that -60 -15 0 4 8 121620 242832 0 4 8 121620242832 the use of partial seismic isolation or not had little effect on the overall seismic perfor- mance of the structur Ti e. me(s) The maximum inter-story displacement an Tigle me(s) of the partial isola- tion structure was 1/180 under a rare earthquake of magnitude 8, which still met the code (a) Acceleration (b) Displacement Buildings 2022, 12, x FOR PEER REVIEW 10 of 17 requirement of 1/50 for the elastic−plastic inter-story displacement angle under a rare Figure 10. Acceleration and displacement time−history curve of the structure top. Figure 10. Acceleration and displacement timehistory curve of the structure top. earthquake. It was thus judged that the partial seismic isolation system had no effect on the seismic response and stability of the overall frame structure. 15 60 Original structure Original structure Isolation structure Isolation structure 0 0 -5 -30 -10 -60 -15 0 4 8 121620 242832 0 4 8 121620242832 Time(s) Time(s) (a) Acceleration (b) Displacement Figure 10. Acceleration and displacement time−history curve of the structure top. (a) (b) Figure 11. (a) Inter−story displacement angle and (b) inter-story shear force. Figure 11. (a) Interstory displacement angle and (b) inter-story shear force. 4. Optimal Design of Partial Seismic Isolation Systems 4. Optimal Design of Partial Seismic Isolation Systems 4.1. Inﬂuence of Bearing Type on Vibration Damping in Isolated Rooms 4.1. Influence of Bearing Type on Vibration Damping in Isolated Rooms To further optimize the partial seismic isolation system and improve the seismic To further optimize the partial seismic isolation system and improve the seismic per- performance of the structure, the effect of different bearing types on the seismic performance formance of the structure, the effect of different bearing types on the seismic performance of the structure was investigated. The study added a partial seismic isolation model using of the structure was investigated. The study added a partial seismic isolation model using natural rubber bearings, which was the same as the partial seismic isolation structural natural rubber bearings, which was the same as the partial seismic isolation structural model in Section 2 except for the bearings. The relevant mechanical performance parameters model in Section 2 except for the bearings. The relevant mechanical performance param- of the natural rubber bearings used are shown in Table 4. eters of the natural rubber bearings used are shown in Table 4. Table 4. Basic parameters of the linear natural rubber bearing. Type of Bear- Effective Diameter Total Rubber Thickness Equivalent Stiffness Vertical Stiffness ing (mm) (mm) (kN/m) (kN/mm) LNR300 300 56 490 900 By comparing the analysis results of the two bearing models with the original frame structure, the seismic response of the partial isolation room is shown in Figure 12. The relative peak accelerations of the partial isolation room under the lead-core rubber bearing 2 2 and natural rubber isolation bearing were 0.46 m/s and 0.51 m/s , and the relative dis- placement peaks were 2.07 mm and 2.52 mm, respectively. Both of them were far less than the partial room seismic response of the original structure, and the lead rubber bearing was better than the natural rubber bearing. Original structure Original structure Lead-core isolation bearing Lead-core isolation bearing Rubber isolation bearing Rubber isolation bearing -10 -3 -20 0 4 8 121620242832 -6 0 4 8 12 16 20 24 28 32 Time(s) Time(s) 0 0 -3 -10 -6 -20 7.0 7.5 8.0 8.5 9.0 7.0 7.5 8.0 8.5 9.0 (a) Relative Acceleration (b) Relative displacement Figure 12. Damping effect of the isolated room. Displacement (mm) -2 Acceleration(m·s ) Displacement (mm) -2 Acceleration(m/s ) Acceleration(m·s ) ZOOM Displacement(mm) Displacement(mm) Displacement(mm) ZOOM Buildings 2022, 12, x FOR PEER REVIEW 10 of 17 (a) (b) Figure 11. (a) Inter−story displacement angle and (b) inter-story shear force. 4. Optimal Design of Partial Seismic Isolation Systems 4.1. Influence of Bearing Type on Vibration Damping in Isolated Rooms To further optimize the partial seismic isolation system and improve the seismic per- formance of the structure, the effect of different bearing types on the seismic performance of the structure was investigated. The study added a partial seismic isolation model using natural rubber bearings, which was the same as the partial seismic isolation structural Buildings 2022, 12, 876 10 of 16 model in Section 2 except for the bearings. The relevant mechanical performance param- eters of the natural rubber bearings used are shown in Table 4. Table 4. Basic parameters of the linear natural rubber bearing. Table 4. Basic parameters of the linear natural rubber bearing. Effective Diameter Total Rubber Equivalent Stiffness Vertical Stiffness Type of Bear- Effective Diameter Total Rubber Thickness Equivalent Stiffness Vertical Stiffness Type of Bearing (mm) Thickness (mm) (kN/m) (kN/mm) ing (mm) (mm) (kN/m) (kN/mm) LNR300 300 56 490 900 LNR300 300 56 490 900 By comparing the analysis results of the two bearing models with the original frame By comparing the analysis results of the two bearing models with the original frame structure, the seismic response of the partial isolation room is shown in Figure 12. The structure, the seismic response of the partial isolation room is shown in Figure 12. The relative peak accelerations of the partial isolation room under the lead-core rubber bearing relative peak accelerations of the partial isolation room under the lead-core rubber bearing 2 2 and natural rubber isolation bearing were 0.46 m/s an2d 0.51 m/s , and the rela 2 tive dis- and natural rubber isolation bearing were 0.46 m/s and 0.51 m/s , and the relative placement peaks were 2.07 mm and 2.52 mm, respectively. Both of them were far less than displacement peaks were 2.07 mm and 2.52 mm, respectively. Both of them were far less the partial room seismic response of the original structure, and the lead rubber bearing than the partial room seismic response of the original structure, and the lead rubber bearing was better than the natural rubber bearing. was better than the natural rubber bearing. Original structure Original structure Lead-core isolation bearing Lead-core isolation bearing 6 10 Rubber isolation bearing Rubber isolation bearing -10 -3 -20 0 4 8 121620242832 -6 0 4 8 12 16 20 24 28 32 Time(s) Time(s) -3 -10 -6 -20 7.0 7.5 8.0 8.5 9.0 7.0 7.5 8.0 8.5 9.0 Buildings 2022, 12, x FOR PEER REVIEW 11 of 17 (a) Relative Acceleration (b) Relative displacement Figure 12. Damping effect of the isolated room. Figure 12. Damping effect of the isolated room. Figure 13 shows the time history curves of the distance between the column of the Figure 13 shows the time history curves of the distance between the column of the seismically isolated room and the adjacent column for both types of bearing, with an ini- seismically isolated room and the adjacent column for both types of bearing, with an initial tial distance of 200 mm, i.e., the width of the reserved seismic isolation joints. The results distance of 200 mm, i.e., the width of the reserved seismic isolation joints. The results show show that the minimum distance between the partial isolation room and the adjacent that the minimum distance between the partial isolation room and the adjacent members members was 167 mm for the lead-core rubber bearing and 108 mm for the natural rubber was 167 mm for the lead-core rubber bearing and 108 mm for the natural rubber bearing, bearing, indicating that no collision occurred between the partial isolation room and the indicating that no collision occurred between the partial isolation room and the adjacent adjacent members under the action of either bearing, and that the partial isolation struc- members under the action of either bearing, and that the partial isolation structure had a ture had a high safety reserve. Because of the greater stiffness of the lead-core rubber iso- high safety reserve. Because of the greater stiffness of the lead-core rubber isolation bearing, lation bearing, the displacement of the partial isolation structure could be better controlled the displacement of the partial isolation structure could be better controlled than with the than with the rubber isolation bearing. rubber isolation bearing. Lead-core isolation bearings Rubber isolation bearings Initial distance 0 4 8 1216 20 242832 Time(s) Figure 13. Distance between the isolated room column and adjacent column. Figure 13. Distance between the isolated room column and adjacent column. Figures 14 and 15 show that the overall seismic response of the structure was ana- lyzed in terms of acceleration, displacement, inter-story displacement angle, and inter- story shear at the top of the structure under the two types of bearing, which had no obvi- ous change with the original structure. Therefore, it was considered that the effect of changing the type of bearing on the overall seismic response of the original frame struc- ture under this partial seismic isolation system was minimal and could be ignored. 18 75 Original structure Original structure Lead-core isolation bearings Lead-core isolation bearings Rubber isolation bearings Rubber isolation bearings 0 0 -6 -25 -12 -50 -18 -75 0 4 8 12 16 20 24 28 32 0 4 8 121620242832 Time(s) Time(s) (a) (b) Figure 14. Time−history curve of the structure top (a) acceleration and (b) displacement. Acceleration(m/s ) Displacement(mm) Acceleration(m/s ) ZOOM Displacement(mm) Displacement(mm) ZOOM Buildings 2022, 12, x FOR PEER REVIEW 11 of 17 Figure 13 shows the time history curves of the distance between the column of the seismically isolated room and the adjacent column for both types of bearing, with an ini- tial distance of 200 mm, i.e., the width of the reserved seismic isolation joints. The results show that the minimum distance between the partial isolation room and the adjacent members was 167 mm for the lead-core rubber bearing and 108 mm for the natural rubber bearing, indicating that no collision occurred between the partial isolation room and the adjacent members under the action of either bearing, and that the partial isolation struc- ture had a high safety reserve. Because of the greater stiffness of the lead-core rubber iso- lation bearing, the displacement of the partial isolation structure could be better controlled than with the rubber isolation bearing. Lead-core isolation bearings Rubber isolation bearings Initial distance 0 4 8 1216 20 242832 Time(s) Buildings 2022, 12, 876 11 of 16 Figure 13. Distance between the isolated room column and adjacent column. Figures 14 and 15 show that the overall seismic response of the structure was ana- Figures 14 and 15 show that the overall seismic response of the structure was analyzed lyzed in terms of acceleration, displacement, inter-story displacement angle, and inter- in terms of acceleration, displacement, inter-story displacement angle, and inter-story shear story shear at the top of the structure under the two types of bearing, which had no obvi- at the top of the structure under the two types of bearing, which had no obvious change ous change with the original structure. Therefore, it was considered that the effect of with the original structure. Therefore, it was considered that the effect of changing the type changing the type of bearing on the overall seismic response of the original frame struc- of bearing on the overall seismic response of the original frame structure under this partial ture under this partial seismic isolation system was minimal and could be ignored. seismic isolation system was minimal and could be ignored. Original structure Original structure Lead-core isolation bearings Lead-core isolation bearings Rubber isolation bearings Rubber isolation bearings 12 50 6 25 -6 -25 -12 -50 -18 -75 0 4 8 12 16 20 24 28 32 0 4 8 121620242832 Time(s) Time(s) (a) (b) Buildings 2022, 12, x FOR PEER REVIEW 12 of 17 Figure 14. Time−history curve of the structure top (a) acceleration and (b) displacement. Figure 14. Timehistory curve of the structure top (a) acceleration and (b) displacement. (a) (b) Figure 15. (a) Inter−story displacement angle and (b) inter-story shear. Figure 15. (a) Interstory displacement angle and (b) inter-story shear. 4.2. Effect of Spatial Variations on Seismic Damping in Vibration Isolated Rooms 4.2. Effect of Spatial Variations on Seismic Damping in Vibration Isolated Rooms In order to apply the research results of the local isolation system to practical engineer- In order to apply the research results of the local isolation system to practical engi- ing, it was necessary to further explore the effect of the spatial variations of an isolation neering, it was necessary to further explore the effect of the spatial variations of an isola- room on the seismic performance of the structure. On the basis of the original model, four tion room on the seismic performance of the structure. On the basis of the original model, additional isolated rooms were arranged on the second, third, and fourth ﬂoors, separately, four additional isolated rooms were arranged on the second, third, and fourth floors, sep- as shown in Figure 16 below. The layout of the isolated room selected the corner, central, arately, as shown in Figure 16 below. The layout of the isolated room selected the corner, and two other characteristic locations on the ﬂoor. The analysis was helpful to ﬁnd the central, and two other characteristic locations on the floor. The analysis was helpful to rules of the optimal position of the isolated room in the structural design. The seismic find the rules of the optimal position of the isolated room in the structural design. The wave inputs and bearing selection were consistent with the above, and a total of 12 partial seismic wave inputs and bearing selection were consistent with the above, and a total of isolation models were established. 12 partial isolation models were established. Figure 17 shows the peak relative acceleration and displacement of the partial isolation rooms for each model. The analysis and calculation results showed that the relative acceleration damping rates of the isolated rooms located on the second, third, and fourth ﬂoors were 90%, 87%, and 83%, respectively, and the relative displacement damping rates were 89%, 85%, and 75%, respectively. It can be seen that as the location of the isolated room moved to the upper ﬂoors, the damping effect of the isolated room decreased, but was still much less than the seismic response of the corresponding room of the original Figure 16. Floor plan (unit: mm). Figure 17 shows the peak relative acceleration and displacement of the partial isola- tion rooms for each model. The analysis and calculation results showed that the relative acceleration damping rates of the isolated rooms located on the second, third, and fourth floors were 90%, 87%, and 83%, respectively, and the relative displacement damping rates were 89%, 85%, and 75%, respectively. It can be seen that as the location of the isolated room moved to the upper floors, the damping effect of the isolated room decreased, but was still much less than the seismic response of the corresponding room of the original structure. Meanwhile, as shown in Figure 16, the in−plane variation in the location of the vibration isolated rooms had no significant effect on their damping effect. Acceleration(m/s ) Displacement(mm) Displacement(mm) Buildings 2022, 12, x FOR PEER REVIEW 12 of 17 (a) (b) Figure 15. (a) Inter−story displacement angle and (b) inter-story shear. 4.2. Effect of Spatial Variations on Seismic Damping in Vibration Isolated Rooms In order to apply the research results of the local isolation system to practical engi- neering, it was necessary to further explore the effect of the spatial variations of an isola- tion room on the seismic performance of the structure. On the basis of the original model, four additional isolated rooms were arranged on the second, third, and fourth floors, sep- Buildings 2022, 12, 876 arately, as shown in Figure 16 below. The layout of the isolated room selected the corner, 12 of 16 central, and two other characteristic locations on the floor. The analysis was helpful to find the rules of the optimal position of the isolated room in the structural design. The seismic wave inputs and bearing selection were consistent with the above, and a total of structure. Meanwhile, as shown in Figure 16, the inplane variation in the location of the 12 partial isolation models were established. vibration isolated rooms had no signiﬁcant effect on their damping effect. Buildings 2022, 12, x FOR PEER REVIEW 13 of 17 Buildings 2022, 12, x FOR PEER REVIEW 13 of 17 Figure 16. Floor plan (unit: mm). Figure 16. Floor plan (unit: mm). Figure 17 shows the peak relative acceleration and displacement of the partial isola- tion rooms for each model. The analysis and calculation results showed that the relative acceleration damping rates of the isolated rooms located on the second, third, and fourth floors were 90%, 87%, and 83%, respectively, and the relative displacement damping rates were 89%, 85%, and 75%, respectively. It can be seen that as the location of the isolated room moved to the upper floors, the damping effect of the isolated room decreased, but was still much less than the seismic response of the corresponding room of the original structure. Meanwhile, as shown in Figure 16, the in−plane variation in the location of the vibration isolated rooms had no significant effect on their damping effect. (a) (b) Figure 17. (a) Peak of relative acceleration and (b) peak of relative displacement. (a) (b) Figure 17. (a) Peak of relative acceleration and (b) peak of relative displacement. Figure 17. (a) Peak of relative acceleration and (b) peak of relative displacement. Figures 18 and 19 show the peak acceleration and displacement at the top of the struc- ture, the inter-story displacement angle, and the inter-story shear for the structure as a Figures 18 and 19 show the peak acceleration and displacement at the top of the Figures 18 and 19 show the peak acceleration and displacement at the top of the struc- whole. It can be seen that the acceleration and displacement, inter-story displacement, and structure, the inter-story displacement angle, and the inter-story shear for the structure as a ture, the inter-story displacement angle, and the inter-story shear for the structure as a shear force decreased as the location of the isolated room moved to the upper floors. The whole. It can be seen that the acceleration and displacement, inter-story displacement, and whole. It can be seen that the acceleration and displacement, inter-story displacement, and best damping effect on the structure as a whole was achieved when the isolated room was shear force decreased as the location of the isolated room moved to the upper ﬂoors. The shear force decreased as the location of the isolated room moved to the upper floors. The located at the fourth floor, where the damping ratio of acceleration and displacement was best damping effect on the structure as a whole was achieved when the isolated room was best damping effect on the structure as a whole was achieved when the isolated room was about 10%, indicating that the elevated location of the isolated room effectively reduced located at the fourth ﬂoor, where the damping ratio of acceleration and displacement was located at the fourth floor, where the damping ratio of acceleration and displacement was the overall seismic response of the structure. The change in the in−plane location of the about 10%, indicating that the elevated location of the isolated room effectively reduced about 10%, indicating that the elevated location of the isolated room effectively reduced isolated rooms had no effect on upgrading the overall seismic performance of the struc- the overall seismic response of the structure. The change in the inplane location of the the overall seismic response of the structure. The change in the in−plane location of the ture. isolated rooms had no effect on upgrading the overall seismic performance of the structure. isolated rooms had no effect on upgrading the overall seismic performance of the struc- ture. (a) (b) Figure 18. (a) Peak acceleration at the top of the structure and (b) peak displacement at the top of Figure 18. (a) Peak acceleration at the top of the structure and (b) peak displacement at the top of the structure. (a) (b) the structure. Figure 18. (a) Peak acceleration at the top of the structure and (b) peak displacement at the top of the structure. Buildings 2022, 12, x FOR PEER REVIEW 14 of 17 Buildings 2022, 12, x FOR PEER REVIEW 14 of 17 Buildings 2022, 12, 876 13 of 16 (a) (b) Figure 19. (a) Inter−story displacement angle and (b) inter-story shear. 4.3. Effect of Load Level on Vibration in Isolated Rooms In addition, by increasing the floor load of the partial isolation room, it was expected (a) (b) that the damping effect would be similar to TMD. In addition, to further investigate the Figure 19. Figure 19. (( aa )) Inter Inter-story −story displacement displaceme angle nt ang and le and ( (b) inter b) inter-story shear. -story shear. effect of partial isolation room loads on the seismic performance of the structure, the con- 4.3. Effect of Load Level on Vibration in Isolated Rooms 2 2 2 stant floor loads o 4. f3. the isolated rooms were Effect of Load Level on Vibration in Isolated Rooms adjusted to 3 kN/m , 6 kN/m , 12 kN/m , and In addition, by increasing the ﬂoor load of the partial isolation room, it was expected 24 kN/m , respectively, and all of the conditions were the same as the isolated structure In addition, by increasing the floor load of the partial isolation room, it was expected that the damping effect would be similar to TMD. In addition, to further investigate the model in Section 2, except for the isolated room loads, and a total of four partial isolation that the damping effect would be similar to TMD. In addition, to further investigate the effect of partial isolation room loads on the seismic performance of the structure, the 2 2 2 models with different effect of partial isolation loads were establ ro ished. om loads on the seismic performance of the structure, the con- constant ﬂoor loads of the isolated rooms were adjusted to 3 kN/m , 6 kN/m , 12 kN/m , 2 2 2 and 24 kN/m , respectively, and all of the conditions were the same as the isolated structure stant floor loads of the isolated rooms were adjusted to 3 kN/m , 6 kN/m , 12 kN/m , and It can be seen in Figures 20–22 that as the partial isolation room loads increased, the model in Section 2, except for the isolated room loads, and a total of four partial isolation 24 kN/m , respectively, and all of the conditions were the same as the isolated structure relative acceleration and displacement of the partial isolation rooms increased, but were models with different loads were established. model in Section 2, except for the isolated room loads, and a total of four partial isolation much smaller than the original structural seismic response. There was no significant It can be seen in Figures 20–22 that as the partial isolation room loads increased, the models with different loads were established. change in peak acceleration, displacement, inter-story displacement angle, and inter-story relative acceleration and displacement of the partial isolation rooms increased, but were It can be seen in Figures 20–22 that as the partial isolation room loads increased, the shear at the top of the structure. There much smaller than the original fore, str it was co uctural seismic nsider response. ed that Ther chang e was ing the mass no signiﬁcantand change relative acceleration and displacement of the partial isolation rooms increased, but were in peak acceleration, displacement, inter-story displacement angle, and inter-story shear load of the partial isolation rooms had little effect on the seismic damping effect of the much smaller than the original structural seismic response. There was no significant at the top of the structure. Therefore, it was considered that changing the mass and load partial rooms and the overall seismic response of the house, and could be ignored. At the change in peak acceleration, displacement, inter-story displacement angle, and inter-story of the partial isolation rooms had little effect on the seismic damping effect of the partial same time, when the floor load of the partial isolation room was 24 kN/m , the defor- rooms and the overall seismic response of the house, and could be ignored. At the same shear at the top of the structure. Therefore, it was considered that changing the mass and mation of the bearing and the shear and bending moment of the beam under the bearing time, when the ﬂoor load of the partial isolation room was 24 kN/m , the deformation of load of the partial isolation rooms had little effect on the seismic damping effect of the the bearing and the shear and bending moment of the beam under the bearing were still were still within the safe range. partial rooms and the overall seismic response of the house, and could be ignored. At the within the safe range. same time, when the floor load of the partial isolation room was 24 kN/m , the defor- mation of the bearing and the shear and bending moment of the beam under the bearing 6 24 Original structure Original structure were still within the safe range. 3kN/m 3kN/m 4.98 19.93 5 20 6kN/m 6kN/m 12kN/m 6 24 12kN/m Original structure Original structure 4 16 24kN/m 3kN/m 24kN/m 3kN/m 4.98 19.93 5 20 6kN/m 6kN/m 3 12 12kN/m 12kN/m 4 2 16 24kN/m 24kN/m 2 8 3 12 1 4 2.53 2.16 0.49 0.44 0.47 1.69 0.42 2 8 2 2 2 2 2 2 2 2 Original structure 3kN/m 6kN 1 /m 12kN/m 24kN/m Original structure 3kN/m 4 6kN/m 12kN/m 24kN/m 2.53 2.16 0.47 0.49 0.42 0.44 1.69 (a) (b) 0 0 2 2 2 2 2 2 2 2 Original structure 3kN/m 6kN/m 12kN/m 24kN/m Original structure 3kN/m 6kN/m 12kN/m 24kN/m Figure 20. (a) Peak of relative acceleration and (b) peak of relative displacement. Figure 20. (a) Peak of relative acceleration and (b) peak of relative displacement. (a) (b) Figure 20. (a) Peak of relative acceleration and (b) peak of relative displacement. Relative acceleration (m/s ) Relative acceleration (m/s ) Relative displacement (mm) Relative displacement (mm) Buildings 2022, 12, x FOR PEER REVIEW 15 of 17 Buildings 2022, 12, 876 14 of 16 Buildings 2022, 12, x FOR PEER REVIEW 15 of 17 16 70 14.88 14.86 14.86 14.83 60.44 59.91 59.54 59.69 59.56 16 70 14.83 14.88 14.86 14.86 60.44 50 59.54 59.91 59.69 59.56 6 20 0 0 2 0 2 2 2 0 2 2 2 6kN/m 12kN/m 22 4kN/m 2 2 2 2 Original structure 3kN/m Original structure 3kN/m 6kN/m 212kN/m 2 24kN/m 2 Original structure 3kN/m 6kN/m 12kN/m 24kN/m 6kN/m 12kN/m 24kN/m Original structure 3kN/m (a) (b) (a) (b) Figure 21. (a) Peak acceleration at the top of the structure and (b) peak displacement at the top of Figure 21. (a) Peak acceleration at the top of the structure and (b) peak displacement at the top of Figure 21. (a) Peak acceleration at the top of the structure and (b) peak displacement at the top of the structure. the structure. the structure. (a) (b) Figure 22. (a) Inter-story displacement angle and (b) inter-story shear. Figure 22. (a) Inter-story displacement angle and (b) inter-story shear. 5. Conclusions 5. Conclusions (a) (b) This paper proposes a novel partial seismic isolation structure system and optimizes it This paper proposes a novel partial seismic isolation structure system and optimizes by changing the type of seismic isolation bearing, the location of the partial isolation room, Figure 22. (a) Inter-story displacement angle and (b) inter-story shear. it by changing the type of seismic isolation bearing, the location of the partial isolation and the load. By comparing the seismic response of the original frame structure with the room, and the load. By comparing the seismic response of the original frame structure partial isolation structural model, the following conclusions are found: with the partial isolation structural model, the following conclusions are found: 5. Conclusions (1) The partial seismic isolation system of the frame structure proposed in the study can (1) The partial seismic isolation system of the frame structure proposed in the study signiﬁcantly reduce the seismic response of the isolated rooms, with a relative acceleration This paper proposes a novel partial seismic isolation structure system and optimizes can significantly reduce the seismic response of the isolated rooms, with a relative accel- and displacement reduction rate up to 90%, which is an obvious effect of seismic reduction. it by changing the type of seismic isolation bearing, the location of the partial isolation eration and displacement reduction rate up to 90%, which is an obvious effect of seismic In addition, the partial seismic isolation system has a high safety reserve and has no effect reduction. In addition, the partial seismic isolation system has a high safety reserve and room, and the load. By comparing the seismic response of the original frame structure on the seismic response and stability of the whole frame structure. has no effect on the seismic response and stability of the whole frame structure. with the partial isolation structural model, the following conclusions are found: (2) The seismic performance of the structure was analyzed by changing the type of (2) The seismic performance of the structure was analyzed by changing the type of (1) The partial seismic isolation system of the frame structure proposed in the study seismic isolation bearing and it was found that the lead-core rubber bearing could better seismic isolation bearing and it was found that the lead-core rubber bearing could better control the relative displacement of the partial isolation room, and the deformation of the can significantly reduce the seismic response of the isolated rooms, with a relative accel- control the relative displacement of the partial isolation room, and the deformation of the bearing was smaller than that of the natural rubber bearing, so the lead-core rubber seismic eration and displacement reduction rate up to 90%, which is an obvious effect of seismic bearing was smaller than that of the natural rubber bearing, so the lead-core rubber seis- isolation bearing was chosen as more ideal. mic isolation bearing was chosen as more ideal. reduction. In addition, the partial seismic isolation system has a high safety reserve and (3) The relative acceleration and displacement of the seismic isolation room decreased (3) The relative acceleration and displacement of the seismic isolation room de- has no effect on the seismic response and stability of the whole frame structure. signiﬁcantly with the lowering of the ﬂoor position of the partial seismic isolation room, creased significantly with the lowering of the floor position of the partial seismic isolation indicating that the developed partial seismic isolation system is more effective in reducing (2) The seismic performance of the structure was analyzed by changing the type of room, indicating that the developed partial seismic isolation system is more effective in the seismic at lower ﬂoors. Moreover, the location of the partial isolation rooms can be seismic isolation bearing and it was found that the lead-core rubber bearing could better reducing the seismic at lower floors. Moreover, the location of the partial isolation rooms control the relative displacement of the partial isolation room, and the deformation of the can be considered according to the functional objectives of the structure. In addition, bearing was smaller than that of the natural rubber bearing, so the lead-core rubber seis- mic isolation bearing was chosen as more ideal. (3) The relative acceleration and displacement of the seismic isolation room de- creased significantly with the lowering of the floor position of the partial seismic isolation room, indicating that the developed partial seismic isolation system is more effective in reducing the seismic at lower floors. Moreover, the location of the partial isolation rooms can be considered according to the functional objectives of the structure. In addition, Acceleration(m/s ) Acceleration(m/s ) Displacement (mm) Displacement (mm) Buildings 2022, 12, 876 15 of 16 considered according to the functional objectives of the structure. In addition, changing the horizontal position of the partial isolation room has a limited effect on the seismic performance of the structure as a whole and on the partial isolation room. (4) Changing the mass and load of the partial isolation room has a negligible effect on the damping effect of the isolated room and on the seismic response of the overall structure. (5) The novel partial isolation system can signiﬁcantly reduce the seismic response of the isolated room, but it has little effect on the overall seismic performance of the structure. More studies will be done to improve the seismic performance of both the isolated room and the structure. Moreover, the nonlinear behavior of the materials will be concerned under greater seismic loads. In addition, there are some limitations in this study that need to be added in the follow-up work, as follows: (1) Some assumptions proposed in the ﬁnite element numerical simulation may differ from the real engineering applications, among which the arrangement and design of the seismic isolation bearings are relatively simple, and the nonlinear response of the main body and the partial isolation structure is not sufﬁciently considered. (2) In order to investigate the damping performance of the partial isolation design method under extreme load conditions, more seismic loads need to be added for effect veriﬁcation, and the effect of near-fault ground shaking with impulsive components on the structure will be further analyzed in the subsequent study. Author Contributions: Conceptualization, B.C.; Data curation, B.C.; Formal analysis, B.C.; Investiga- tion, B.C. and J.X.; Methodology, B.C., J.X. and Y.X.; Project administration, J.X.; Resources, Y.L.; Soft- ware, Y.Q. and Y.L.; Supervision, B.C. and J.X.; Validation, Y.Q.; Visualization, Y.Q.; Writing—original draft, Y.Q.; Writing—review & editing, Y.L. All authors have read and agreed to the published version of the manuscript. Funding: This work was ﬁnancially supported by the China Earthquake Administration Basic Research Project (grant number 2018D18), the National Natural Science Foundation of China (grant numbers 51868048), and the Jiangxi Department of Education of Youth Science Fund (60221). Conﬂicts of Interest: We conﬁrm that the manuscript has been read and approved by all of the named authors and that there are no other persons who satisﬁed the criteria for authorship but are not listed. We further conﬁrm that the order of authors listed in the manuscript has been approved by all of us. References 1. Tan, D.Y.; Yang, Q.S. Analysis of seismic performance of partially isolated structures. Earthq. Eng. Eng. Dyn. 1993, 2, 66–74. [CrossRef] 2. Morales, E.; Filiatrault, A.; Aref, A. Seismic ﬂoor isolation using recycled tires for essential buildings in developing countries. Bull. Earthq. Eng. 2018, 16, 6299–6333. [CrossRef] 3. Losanno, D.; Ravichandran, N.; Parisi, F.; Calabrese, A.; Serino, G. Seismic performance of a Low-Cost base isolation system for unreinforced brick Masonry buildings in developing countries. Soil Dyn. Earthq. Eng. 2021, 141, 106501. [CrossRef] 4. Vaiana, N.; Losanno, D.; Ravichandran, N. A novel family of multiple springs models suitable for biaxial rate-independent hysteretic behavior. Comput. Struct. 2021, 244, 106403. [CrossRef] 5. Losanno, D.; Palumbo, F.; Calabrese, A.; Barrasso, T.; Vaiana, N. Preliminary Investigation of Aging Effects on Recycled Rubber Fiber Reinforced Bearings (RR-FRBs). J. Earthq. Eng. 2021, 1–18. [CrossRef] 6. Baggio, S.; Berto, L.; Rocca, I.; Saetta, A. Vulnerability assessment and seismic mitigation intervention for artistic assets: From theory to practice. Eng. Struct. 2018, 167, 272–286. [CrossRef] 7. Pellecchia, D.; Feudo, S.L.; Vaiana, N.; Dion, J.; Rosati, L. A procedure to model and design elastomeric-based isolation systems for the seismic protection of rocking art objects. Comput.-Aided Civ. Infrastruct. Eng. 2021. [CrossRef] 8. Pellecchia, D.; Sessa, S.; Vaiana, N.; Rosati, L. Comparative Assessment on the Rocking Response of Seismically Base-Isolated Rigid Blocks. Procedia Struct. Integr. 2020, 29, 2452–3216. [CrossRef] 9. Mezghani, F.; del Rincón, A.F.; Fernandez, P.G.; De-Juan, A.; Sanchez-Espiga, J.; Rueda, F.V. Effectiveness study of wire mesh vibration damper for sensitive equipment protection from seismic events. Mech. Syst. Signal Processing 2022, 164, 108160. [CrossRef] 10. Jia, G.; Gidaris, I.; Taﬂanidis, A.A.; Mavroeidis, G.P. Reliability-based assessment/design of ﬂoor isolation systems. Eng. Struct. 2014, 78, 41–56. [CrossRef] Buildings 2022, 12, 876 16 of 16 11. Wu, Y.X.; Huang, J.; Lin, S.Z.; Qi, A. Design and application status of seismic isolation constitution of building. China Civ. Eng. J. 2018, 51, 62–73+94. [CrossRef] 12. Cheng, R.; Chen, W.; Hao, H.; Li, J. A state-of-the-art review of road tunnel subjected to blast loads. Tunn. Undergr. Space Technol. 2021, 112, 103911. [CrossRef] 13. Ning, X.Q.; Dai, J.W. A review of seismic resilience and performance-based seismic study of non-structural systems. Earthq. Eng. Eng. Dyn. 2017, 37, 85–92. [CrossRef] 14. Cheng, R.; Zhou, Z.; Chen, W.; Hao, H. Effects of Axial Air Deck on Blast-Induced Ground Vibration. Rock Mech. Rock Eng. 2021, 55, 1037–1053. [CrossRef] 15. Yin, X.S.; Li, Y.Y.; Li, B.L.; Sun, L.-Y. A new method for vertical damping with TMD system. Earthq. Resist. Eng. Retroﬁt. 2020, 42, 57–63. [CrossRef] 16. Deringöl, A.H.; Güneyisi, E.M. Inﬂuence of nonlinear ﬂuid viscous dampers in controlling the seismic response of the base-isolated buildings. Structures 2021, 34, 1923–1941. [CrossRef] 17. Chen, W.; Tao, Z.; Dai, B.H. Seismic control method, properties and practical engineering analysis of main structure retroﬁtted with attached damping structure. J. Build. Struct. 2021, 42, 92–100. [CrossRef] 18. Ye, L.H.; Qu, Z.; Sun, H.L.; Gong, T. Earthquake loss evaluation of medical facility seismically retroﬁtted by different seismic damage control methods. J. Build. Struct. 2020, 41, 15–26. [CrossRef] 19. Murota, N.; Suzuki, S.; Mori, T.; Wakishima, K.; Sadan, B.; Tuzun, C.; Sutcu, F.; Erdik, M. Performance of high-damping rubber bearings for seismic isolation of residential buildings in Turkey. Soil Dyn. Earthq. Eng. 2021, 143, 106620. [CrossRef] 20. Sung, Y.C.; Hung, H.H.; Chou, K.W.; Su, C.K.; Hsu, C.W. Shaking table testing of a reinforced concrete frame retroﬁtted with a steel oval member equipped with rubber cylinders. Eng. Struct. 2021, 237, 112202. [CrossRef] 21. Zheng, J.Y.; Song, W.; Lei, Y.D.; Wang, T. Shaking table test study on friction-pendulum isolated frame structures. China Civ. Eng. J. 2020, 53, 240–245. [CrossRef] 22. Xu, X.; Zhang, Y.; Luo, Y. Self-centering eccentrically braced frames using shape memory alloy bolts and post-tensioned tendons. J. Constr. Steel Res. 2016, 125, 190–204. [CrossRef] 23. Yang, Q.R.; Wang, L.Y.; Liu, W.G.; Xu, H.; Xu, H. Mechanical model and experimental research of the inclined rotational three-dimensional seismic isolation device. J. Vib. Eng. 2021, 34, 462–471. [CrossRef] 24. Li, S.; Wei, B.; Tan, H.; Li, C.; Zhao, X. Equivalence of friction and viscous damping in a spring-friction system with concave friction distribution. J. Test. Eval. 2020, 49, 372–395. [CrossRef] 25. Yan, G.Y.; Xiao, X.F.; Wu, Y.X.; Li, C.; Zhao, X. Shaking table test of isolated single-tower structures with a large chassis under near-fault ground motions. J. Vib. Eng. 2018, 31, 799–810. [CrossRef] 26. Özuygur, A.R.; Noroozinejad Farsangi, E. Inﬂuence of Pulse-Like Near-Fault Ground Motions on the Base-Isolated Buildings with LRB Devices. Pract. Period. Struct. Des. Constr. 2021, 26, 04021027. [CrossRef] 27. Islam, A.; Al-Kutti, W.A. Seismic response variation of multistory base-isolated buildings applying lead rubber bearings. Comput. Concr. 2018, 21, 495–504. [CrossRef] 28. Zhang, R.F.; Wu, M.R.; Zhou, F.Y.; Wu, Y.X.; Jiang, J.L. Research on mid-story isolation of structure using inerter isolation system. World Earthq. Eng. 2020, 36, 8–16. [CrossRef] 29. Liu, Y.H.; Liu, X.H.; Tan, P. Dynamic reliability for inter-story hybrid isolation structure. J. Vib. Eng. 2019, 32, 324–330. [CrossRef] 30. Vaiana, N.; Spizzuoco, M.; Serino, G. Wire rope isolators for seismically base-isolated lightweight structures: Experimental characterization and mathematical modeling. Eng. Struct. 2017, 140, 0141–0296. [CrossRef] 31. Basar, T.; Deb, S.K.; Das, P.J.; Sarmah, M. Seismic response control of low-rise unreinforced masonry building test model using low-cost and sustainable un-bonded scrap tyre isolator (U-STI). Soil Dyn. Earthq. Eng. 2021, 142, 106561. [CrossRef] 32. Engle, T.; Mahmoud, H.; Chulahwat, A. Hybrid Tuned Mass Damper and Isolation Floor Slab System Optimized for Vibration Control. J. Earthq. Eng. 2015, 19, 1197–1221. [CrossRef] 33. Kong, D.R.; Yang, Z.Q.; Wei, L.S.; Zhang, Y.S.; Zhang, T.J. Research on seismic parameters of multistory isolated structure with limit design. Earthq. Resist. Eng. Rotroﬁtting 2021, 43, 96–102+118. [CrossRef] 34. Li, F.Y.; Zhou, D.Y.; Zhong, Y.C.; Zhang, H. Seismic Performance Analysis of an Existing Medical Building Strengthened by Seismic Isolation Technology. Struct. Eng. 2021, 37, 167–176. [CrossRef] 35. JG/T 118-2018 [S]; Rubber Isolation Bearings for Buildings. Standards Press of China: Beijing, China, 2018. 36. Wei, B.; Hu, Z.; He, X.; Jiang, L. Evaluation of optimal ground motion intensity measures and seismic fragility analysis of a multi-pylon cable-stayed bridge with super-high piers in mountainous areas. Soil Dyn. Earthq. Eng. 2020, 129, 105945. [CrossRef] 37. Hu, Z.; Wei, B.; Jiang, L.; Li, S.; Yu, Y.; Xiao, C. Assessment of optimal ground motion intensity measure for high-speed railway girder bridge (HRGB) based on spectral acceleration. Eng. Struct. 2022, 252, 113728. [CrossRef] 38. GB 50011-2010 [S]; Code for Seismic Design of Buildings. China Architecture & Building Press: Beijing, China, 2010.

http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png

Buildings Multidisciplinary Digital Publishing Institute

http://www.deepdyve.com/lp/multidisciplinary-digital-publishing-institute/seismic-performance-and-optimization-of-a-novel-partial-seismic-00Bjo0hWas

Seismic Performance and Optimization of a Novel Partial Seismic Isolation System for Frame Structures

Loading next page...

Publisher: Multidisciplinary Digital Publishing Institute
Copyright: © 1996-2022 MDPI (Basel, Switzerland) unless otherwise stated Disclaimer The statements, opinions and data contained in the journals are solely those of the individual authors and contributors and not of the publisher and the editor(s). MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. Terms and Conditions Privacy Policy
ISSN: 2075-5309
DOI: 10.3390/buildings12070876
Publisher site: See Article on Publisher Site

Abstract

Journal

Buildings – Multidisciplinary Digital Publishing Institute

Published: Jun 22, 2022

Keywords: partial seismic isolation; frame structure; numerical simulation; seismic performance; isolation bearing

Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 14-Day Trial for You or Your Team.

Learn More →

Seismic Performance and Optimization of a Novel Partial Seismic Isolation System for Frame Structures

Seismic Performance and Optimization of a Novel Partial Seismic Isolation System for Frame Structures

Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 14-Day Trial for You or Your Team.

Learn More →

Seismic Performance and Optimization of a Novel Partial Seismic Isolation System for Frame Structures

Seismic Performance and Optimization of a Novel Partial Seismic Isolation System for Frame Structures

Abstract

Journal

Recommended Articles

There are no references for this article.

Our policy towards the use of cookies