地下结构对工程场地地震动场的影响     

朱小乔  楼梦麟  孔祥海 《震灾防御技术》2011,6(1):49-58

本文以日本神户市地铁大开站为工程背景,应用大型通用有限元ANSYS软件,分别建立了自然条件下的工程场地土层和建有地下车站结构的土层的二维有限元分析模型。计算了基岩一致地震动输入模式下2个土层模型的动力反应。通过将2个土层模型的动力反应进行比较分析,讨论了地下结构对工程场地地震动场的影响。分析结果表明,日本神户地铁大开站的存在对其邻近区域土层的地震反应有影响,但影响有限。  相似文献   

A simulation‐based framework for risk assessment and probabilistic sensitivity analysis of base‐isolated structures     

Alexandros A. Taflanidis  Gaofeng Jia 《地震工程与结构动力学》2011,40(14):1629-1651

A versatile, simulation‐based framework for risk assessment and probabilistic sensitivity analysis of base‐isolated structures is discussed in this work. A probabilistic foundation is used to address the various sources of uncertainties, either excitation or structural, and to characterize seismic risk. This risk is given, in this stochastic setting, by some statistics of the system response over the adopted probability models and stochastic simulation is implemented for its evaluation. An efficient, sampling‐based approach is also introduced for establishing a probabilistic sensitivity analysis to identify the importance of each of the uncertain model parameters in affecting the overall risk. This framework facilitates use of complex models for the structural system and the excitation. The adopted structural model explicitly addresses nonlinear characteristics of the isolators and of any supplemental dampers, and the effect of seismic pounding of the base to the surrounding retaining walls. An efficient stochastic ground motion model is also discussed for characterizing future near‐fault ground motions and relating them to the seismic hazard for the structural site. An illustrative example is presented that emphasizes the results from the novel probabilistic sensitivity analysis and their dependence on seismic pounding occurrences and on addition of supplemental dampers. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

Effect of roll modelling in beam waves under multi-frequency excitation     

G. Bulian  A. Francescutto 《Ocean Engineering》2011,38(13):1448-1463

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Parametric vibration of submerged floating tunnel tether under random excitation     

孙胜男  苏志彬 《中国海洋工程》2011,25(2):349-356

For the study of the parametric vibration response of submerged floating tunnel tether under random excitation,a nonlinear random parametric vibration equation of coupled tether and tube of submerged floating tunnel is set up.Subsequently,vibration response of tether in the tether-tube system is analyzed by Monte Carlo method.It may be concluded that when the tube is subjected to zero-mean Gaussian white noise random excitation,the displacement and velocity root mean square responses of tether reach the peak if the circular frequency of tube doubles that of tether;the displacement and velocity root mean square responses of tether increase as the random excitation root mean square increases;owing to the damping force of water,the displacement and velocity root mean square responses of tether decrease rapidly compared with tether in air;increasing the damping of the tether or tube reduces the displacement and velocity root mean square responses of tether;the large-amplitude vibration of tether may be avoided by locating dampers on the tether or tube.  相似文献   

Seismic behavior of single‐story asymmetric‐plan buildings under uniaxial excitation     

Andrea Lucchini  Giorgio Monti  Sashi Kunnath 《地震工程与结构动力学》2009,38(9):1053-1070

The critical parameters that influence the nonlinear seismic response of asymmetric‐plan buildings are identified by evaluating the effects of different asymmetries that may characterize the structure of a building as well as exploring the influence of the ground motion features. First, the main findings reported in the literature on both the linear and nonlinear dynamic response of asymmetric‐plan buildings are presented. The common findings and the conflicting conclusions reached in different investigations are pointed out. Then, the results of comprehensive nonlinear dynamic analyses performed for evaluating the seismic response of systems characterized by different strength and stiffness configurations, representative of a large class of asymmetric‐plan buildings, are reported. Findings from the study indicate that the building response changes when moving from the linear to the nonlinear range, so that the seismic behavior of asymmetric‐plan buildings, apart from the source of asymmetry, can be always classified as irregular. Additionally, it was observed that as the seismic demands cause amplification of system nonlinearity with increasing earthquake intensity, the maximum displacement demand in the different resisting elements tends to be reached with the same deformed configuration of the system. The resultant of the seismic forces producing such a maximum demand is located at the center of resistance and corresponds to the collapse mechanism of the system that provides the maximum lateral strength in the exciting direction of the seismic action. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

竖向地震下双塔连体建筑的分析和设计     

侯家健  容柏生  韩小雷  谭平  陈建秋  谢毅源 《华南地震》2008,28(4):63-74

首先输入多条实际竖向地震记录,用时程分析考察了塔楼高度和连体跨度不同的多个算例。然后将其抽象成塔楼和连体桁架组成的双自由度体系,运用频域分析方法,得到竖向地震作用的变化规律：11随着桁架对塔楼频率比增加,连体地震放大作用越明显;2）当连体对塔楼质量比较小且两者频率比相近1,连体地震反应进一步加强。现行抗震规范的重力系数法提出的大跨度结构竖向地震的实用计算公式对于本文研究结构并不完全适用。提出考虑塔楼和桁架协同地震作用的实用算式,并对一个超高层工程实例进行竖向地震作用分析,与时程分析结果吻合较好。  相似文献   

Decentralized robust control of building structures under seismic excitations     

Tian‐Wei Ma  Ning‐Shou Xu  Yu Tang 《地震工程与结构动力学》2008,37(1):121-140

Many of the control algorithms proposed for structures subjected to seismic excitations are based on a centralized design philosophy, such as the linear quadratic regulator (LQR) design. The information of all the states of the system is usually required in these methods to determine the control command. For applications involving large‐scale systems, it may be more convenient to design decentralized controllers that depend only on the information of the local states for control command calculation. In this study, a nonlinear decentralized robust control algorithm is proposed. The structural system is decomposed into several artificially uncoupled subsystems. The interconnections between adjacent subsystems are treated as uncertain but bounded disturbances to the subsystems. The controller associated with one subsystem determines the control command based only on the states of the local subsystem. Numerical examples of linear and nonlinear structural models are presented to demonstrate the effectiveness and robustness of the proposed controller. The traditional LQR design is used as a baseline for comparison. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

竖向地震动对滑动摩擦隔震桥梁结构地震反应的影响     

王常峰  陈兴冲  夏修身 《世界地震工程》2008,24(4)

利用接触摩擦单元建立了滑动摩擦隔震桥梁支座在竖向地震动作用下的有限元模型,通过算例讨论了竖向地震动对不同支座摩擦系数和不同刚度(墩径)滑动摩擦隔震桥梁地震反应的影响,初步探讨了竖向地震动的激励方向对分析结果的影响,分析结果表明,竖向地震动对滑动摩擦隔震桥梁结构的地震反应有较大的影响,在竖向地震动较为明显地区的滑动摩擦隔震桥梁结构设计时,应予以考虑。  相似文献   

地震动差动作用下大跨度空间网壳结构的反应分析   总被引：1，自引：0，他引：1  

白凤龙  李宏男  全伟 《地震学刊》2009,(2):154-160

选取100m跨度的双层柱面网壳结构为研究对象,采用时程分析法,分别进行了结构在单向和三向地震行波输入作用下的反应分析,并针对多种视波速情况进行了研究,考查了地震动不同输入情况下结构杆件内力的分布特点,对其进行了对比分析,为大跨网壳结构的抗震设计提供了理论依据。研究表明,考虑行波效应会使结构部分构件内力有一定程度的提高,多维地震作用比单维地震作用下结构的杆件内力大。由此得出结论：对于大跨度空间网壳结构,应该进行多维非一致输入下的地震反应分析;为保证抗震安全,应对可能出现的地面视波速进行全面分析。  相似文献   

THE THEORY OF RESPONSE ANALYSIS OF FUZZY STOCHASTIC DYNAMICAL SYSTEMS WITH A SINGLE DEGREE OF FREEDOM     

Y. ZHANG  G. WANG  F. SU  Z. QIAO 《地震工程与结构动力学》1996,25(3):235-251

Most real-life structural/mechanical systems have complex geometrical and material properties and operate under complex fuzzy environmental conditions. These systems are certainly subjected to fuzzy random excitations induced by the environment. For an analytical treatment of such a system subjected to fuzzy random excitations, it becomes necessary to establish the general theory of dynamic response of a system to fuzzy random excitations. In this paper, the theory of response, fuzzy mean response and fuzzy covariance response of a single-degree-of-freedom (sdf) system to fuzzy random excitations in the time domain and frequency domain is put forward. The theory of response analysis of an sdf system to both stationary and non-stationary fuzzy random excitations in the time domain and frequency domain is established. Two examples are considered in order to demonstrate the rationality and validity of the theory, and the models of stationary filtered white noise and non-stationary filtered white noise fuzzy stochastic processes of the earthquake ground motion are set up. Methods of analysis for fuzzy random seismic response of sdf systems are put forward using the principles of response analysis of an sdf fuzzy random dynamic system.  相似文献