Elastic-Plastic Analysis on Damaged Multi-Tower Isolation Structure with an Enlarged Base

2011 ◽  
Vol 255-260 ◽  
pp. 2550-2554 ◽  
Author(s):  
Nan Zhao ◽  
Hai Xia Geng ◽  
Kai Ma ◽  
Kang Ning Li

The analysis on earthquake response of one multi-tower isolation structure with an enlarged base in rare earthquake and aftershocks was carried out using elastic time history analysis method. It includes the damping effect of structure, plastic deformation of members and plastic hinges distribution in structure. The results show that isolation structure comes to plastic state under rare earthquake lighter, vertical elements remain flexible under earthquake aftershocks, the plastic hinges on horizontal members are deepen, but the structure can meet the requirement while it is renovated. Plastic hinges first appear in the bottom of structure, then they gradually develop upwards, Plastic hinges are generated at the ends of beams, but not occur in columns and walls. The displacement of structure under rare earthquake is mainly concentrated on isolation layer and it can take energy consumption by large displacement.

2013 ◽  
Vol 353-356 ◽  
pp. 2177-2180
Author(s):  
Hao Ming Cai ◽  
Zhong Tao ◽  
Xin Li Cao

In this paper, we calculate and analyze a tall building project of seismic isolation design. It is a frame-shear wall structure, which has twelve stories on the ground. And then, we use the time history analysis method to calculate the isolation structure. It is found that isolation equipment can extend the period of the structure, reduce the story drift in frequency earthquake. And it also can control the response of the structure. In rare earthquake, the story drift can meet the demand of unclasped; the displacement and force of the equipment can satisfy the demand of the code for seismic design of building.


2013 ◽  
Vol 353-356 ◽  
pp. 2105-2109
Author(s):  
Guo Chen Zheng ◽  
Hang Li Xu

The multi-mass analysis models of story isolation and general structure are established, major parameters are optimized on story isolation structure, with time-history analysis for isolation layers in different position, the contributions of modes and damping effects of absolute acceleration and story drift about story-isolation structure are analysed. Result indicates that after the parametric optimization, the natural period of story-isolation structure is longer than that of general structure; no matter where the position of isolation layer is, the damping effects are always obviously; the position of isolation layer has direct influence on the damping effect, damping effect gradually reduce when the isolation layer raised, and the contributions of high modes to dynamic responses increase; it's worth noting that infrastructure absolute acceleration magnify to some extent compared with general structure.


2012 ◽  
Vol 594-597 ◽  
pp. 1640-1644
Author(s):  
Yun Xiang He ◽  
Yue Qiang ◽  
Li Li

With vigorous development of hydroelectric source in west China, the anti-seismic security issue of dam engineering attracted particular attention. This paper presented the principle of dynamic time-history analysis method and established the model with the assistance of finite element method and combined with practical engineering for further analysis on the dynamic response of displacement and stress of dam’s dynamic time-history analysis to the time history. According to the result, it is feasible and necessary to apply the dynamic time-history analysis method to study the anti-seismic performance of the dam. Furthermore, it pointed out the weak part of the dam in anti-seismic function as well as the area concentrated with critical stress, providing reference for future anti-seismic engineering and shock resistance.


2010 ◽  
Vol 163-167 ◽  
pp. 4442-4448
Author(s):  
Xing Zhu Pei ◽  
Wei Wang

The basal theory of energy method is introduced, which makes use of the idea of energy balance to study the earthquake response of structures. Because of the high stiffness and low-cost of the steel frame-reinforced concrete shear wall hybrid structure, it is being widely used. But the study of the earthquake response prediction method of the structure has not been done yet. In this paper, energy method is used to study the earthquake response of the steel frame-reinforced concrete shear wall hybrid structure. A steel frame structure and a steel frame-reinforced concrete shear wall hybrid structure have been designed. The shear wall in steel frame-reinforced concrete shear wall hybrid structure is simplified as a column for easier study. In order to evaluate the results of the energy method, the time history analysis method is also used to study the earthquake response of the two structures. The shear coefficient, maximal interlaminar displacement and damage ratio of the two structures are studied. After comparison, it is found that the results of energy method and the time history analysis method are almost the same. The energy method can be easily used to study the earthquake response of the steel frame-reinforced concrete shear wall hybrid structure.


2010 ◽  
Vol 163-167 ◽  
pp. 4027-4031
Author(s):  
Jin Hui Liu ◽  
Wan Tao Ding

Based on isolation theory, time-history analysis on isolation system with limiting displacement protective devices was studied by Fortran program. Isolation effect of non-isolated structure, isolated structure and limit isolated structure were analyzed. Adhesion phenomenon of algorithm is solved by subdividing time steps during program analysis. And it gets good effect. According to comparing with isolation effect of different isolated structure, the result that isolation effect of isolated structure and limit isolated structure is obvious is reward; and limit isolated structure can isolation and prevent large displacement of isolation layers to avoid structure failure under rare earthquake condition. So limit isolated structure plays a double protection for structure.


Abstract. Seismic fragility analysis is essential for seismic risk assessment of structures. This study focuses on the damage probability assessment of the mid-story isolation buildings with different locations of the isolation system. To this end, the performance-based fragility analysis method of the mid-story isolation system is proposed, adopting the maximum story drifts of structures above and below the isolation layer and displacement of the isolation layer as performance indicators. Then, the entire process of the mid-story isolation system, from the initial elastic state to the elastic-plastic state, then to the limit state, is simulated on the basis of the incremental dynamic analysis method. Seismic fragility curves are obtained for mid-story isolation buildings with different locations of the isolation layer, each with fragility curves for near-field and far-field ground motions, respectively. The results indicate that the seismic fragility probability subjected to the near-field ground motions is much greater than those subjected to the far-field ground motions. In addition, with the increase of the location of the isolation layer, the dominant components for the failure of mid-story isolated structures change from superstructure and isolation system to substructure and isolation system.


2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Hongxian Chu ◽  
Yongcai Feng ◽  
Huijie Shi ◽  
Liancheng Hao ◽  
Yiqi Gao ◽  
...  

The Newmark seismic time-history analysis method can take into account the effects of natural seismic peak ground acceleration (PGA), duration, and seismic frequency; seismic wave can be input into the method for simulation. This study calculates the dynamic response of the typical seabed slope of Caofeidian in the event of a similar Tangshan earthquake, and the displacement value can be used to quantitatively reflect the influence of the earthquake on the slope of the site. The allowable displacement value of the top of buildings or submarine slope can be used as a marker of security and stability analysis, which can further provide important reference for similar slope stability evaluation and offshore engineering construction.


2012 ◽  
Vol 166-169 ◽  
pp. 2164-2170
Author(s):  
Xu Jie Sun ◽  
Hou Zhang ◽  
Da Gang Lu ◽  
Feng Lai Wang

The design process of the 100 m high reinforced concrete masonry building in China was firstly presented, deformation check calculation under earthquake action by mode-superposition response spectrum method and time-history analysis method were detailed and deformation under wind load was also checked. Then elastic-plastic deformation under earthquake action was checked by time-history analysis method and pushover analysis method with both under uniform load and reverse triangle load. The conclusion is construct 100 m high office building built in Fortification intensity 6 by reinforced concrete masonry is feasible. Then the building was redesigned as built in fortification 7, the same check was performed as that have been done in fortification 6, it is feasible too.


2013 ◽  
Vol 351-352 ◽  
pp. 849-853
Author(s):  
Lan Chen ◽  
De Long Lu ◽  
Xiao Gang Yin

Based on the vertical seismic information, the vertical seismic response spectrum was calculated by Matlab Lsim function. The seismic effect of Kiewitt-Lamella suspended-dome was measured by dynamic to static ratio. According to the EL-Centro seismic wave, it analyzed and compared the dynamic to static ratios which were calculated by the following four vertical seismic calculation methods respectively: the simplified method of specification, the mode-superposition response spectrum methods based on the horizontal earthquake affecting coefficients and the vertical acceleration response spectrum respectively, and the time history analysis method. Analysis shows that: For the seismic effect, the time history analysis method is larger than the other three methods, and the method based on the vertical acceleration response spectrum is closer to the time history analysis method. Owing to large difference of the four methods for seismic effect, various methods should be adopted to ensure the safety of vertical seismic design.


2013 ◽  
Vol 639-640 ◽  
pp. 896-900
Author(s):  
Ying Yuan ◽  
Ai Hong Zhou ◽  
Yan Li Gao

Different friction bearing ratios have effects on the base isolation property of parallel composite isolation system subjected to the seismic excitation. In order to deeply investigate how the friction bearing ratio affect the isolation property, the numerical simulation was carried out by the time-history analysis method, in which the seismic response of parallel composite isolation system with different friction bearing ratios under different acceleration peak values were calculated. Then, the effects of different friction bearing ratios on the base maximum shear coefficients and base maximum displacements; the hysteretic characteristics and nonlinear properties were analyzed and discussed. The results show that, for the parallel composite isolation system, friction bearing ratio is a key factor affecting the isolation property and the nonlinear properties are tightly related to the friction bearing ratio and acceleration peak values.


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