宁夏地区中小地震震源参数的研究     

许英才  许文俊  李鸿庭 《地震地磁观测与研究》2011,32(6):35-41

利用宁夏及邻区的数字测震资料,选取2009年5月至2010年10月间的31个M2.7-ML4.9地震事件的波形记录,以Brune提出的震源谱为平方模型基础,通过消除观测谱中的几何扩散、非弹性衰减、场地响应、仪器响应等影响因素,得到这些地震的震源谱,根据Brune的圆盘震源模型计算并研究地震矩、矩震级、地震应力降、震源尺...  相似文献   

高淳台地磁异常与地震关系     

夏孝田 《华北地震科学》2011,29(2):49-52

应用差分法分析了高淳台、溧阳台、高邮台、连云港台、宿迁台、海安台地磁垂直分量Z的变化,以加卸载响应比方法研究地磁极值的变化,用Z极小值时间进行地磁低点位移分析,对这些台站资料进行相关分析,研究发现中强震前高淳台的地磁场存在明显的异常变化.  相似文献   

抗震设计反应谱的标定方法   总被引：3，自引：0，他引：3  

郭晓云  薄景山  张宇东  孙有为  李平 《世界地震工程》2011,27(1)

抗震设计反应谱是结构抗震设计的主要依据,设计反应谱的标定是确定地震动输入的重要环节。文中详细地总结了设计反应谱标定的基本原理和几种常用的设计反应谱标定方法,介绍了我国建筑抗震设计反应谱参数的确定方法和统一抗震设计反应谱的研究现状及应用前景;对不同设计反应谱标定方法中存在的问题进行了评述;提出抗震设计反应谱标定方法中有待进一步研究的问题。  相似文献   

节点刚度对单层柱面网壳地震响应及内力的影响分析   总被引：1，自引：0，他引：1  

薛素铎  王宁  李雄彦  梁劲 《世界地震工程》2011,27(3)

论文首先采用壳单元Shell163建立了单层柱面网壳模型,同时利用壳单元模拟了焊接空心球节点,并通过计算验证了模拟方法的合理性。然后,通过调节空心球节点的厚度,考察了节点刚度变化对单层柱面网壳地震响应的影响,分析结果表明,在强震作用下节点刚度变化对网壳节点响应与杆件内力的影响均较大,建议在进行此类结构的动力分析时考虑节点刚度的影响。  相似文献   

Influence of the mean period of ground motion on the inelastic dynamic response of single and multi degree of freedom systems   总被引：1，自引：0，他引：1  

M. Kumar  J. M. Castro  P. J. Stafford  A. Y. Elghazouli 《地震工程与结构动力学》2011,40(3):237-256

This paper focuses on examining the effects of frequency content of the ground motion on the inelastic demands imposed on both single degree of freedom (SDF) and multi degree of freedom (MDF) steel‐framed systems. A detailed literature review is conducted to identify the indicator that best represents the frequency content of ground motion. The mean period (T_m) of ground motion is selected owing to its ability to distinguish between various spectral shapes of ground motion, and its relationship with magnitude, distance and site characteristics. Inelastic displacement demands on SDF systems for target ductility levels are first studied in the light of T_m, using a suite of 128 ground motion records. The study is then extended to MDF systems with the help of incremental dynamic analysis by employing the same ground motion ensemble to assess the influence of T_m on various engineering demand parameters. The results obtained indicate that, for SDF systems, the amplification of displacements occurs when the period ratio between elastic period (T_e) and T_m is lower than unity. For MDF systems, the results demonstrate that the influence of higher modes on the base shear and maximum storey drift profile becomes more pronounced, as T_m approaches the higher mode periods of the structure. These observations, for both SDF and MDF systems, tend to be more evident for higher levels of inelasticity. The significance of the results, with particular reference to European seismic design procedures, is highlighted. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

Effect of hysteretic smoothness on inelastic response spectra with constant‐ductility     

Jong‐Keol Song  Henri P. Gavin 《地震工程与结构动力学》2011,40(7):771-788

This paper presents an efficient methodology for computing constant‐ductility inelastic response spectra. The computation of constant‐ductility spectra involves numerical root‐finding algorithms to find the strongest structure providing a desired ductility response. Smooth inelastic structural behavior is modeled using a first‐order nonlinear differential equation and the transient structural response is solved using an implicit algorithm requiring Newton iterations at each time step. For structural models with smooth hysteretic behavior (not piece‐wise linear), a simple root‐finding method involving a combination of hyperbolic fits, linear interpolation, and Newton's method converges upon the highest strength (conservative) solution with a small number of iterations. The effect of the hysteretic smoothness on the occurrence of multiple roots is examined for two near‐fault and two far‐fault earthquake records, and for two measures of ductility and for normalized hysteretic energy. The results indicate how the smoothness of the hysteretic behavior affects ductility demand and constant‐ductility response spectra. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

县(市)绝对地震应急能力评估方法的初步研究   总被引：4，自引：0，他引：4       下载免费PDF全文

邓砚  聂高众  苏桂武 《地震地质》2011,33(1):36-44

县(市)地震应急能力的高低直接关系到中国整个地震应急工作的成效.从县(市)绝对地震应急能力的内涵分析出发,结合汶川地震灾区县(市)地震应急能力实地调研工作取得的认识,首先初步构建了县(市)绝对地震应急能力指标体系框架;然后以四川省县(市)为例,在遵循科学性、系统优化和可操作性原则的基础上,构建了围绕着1个目标层,设定5...  相似文献   

振动台试验模型地震反应的HHT研究   总被引：1，自引：1，他引：0       下载免费PDF全文

石春香  李胡生  罗奇峰  施卫星 《地震学报》2011,33(1):114-119

Hilbert-Huang Transform(HHT)是一种新的适用于非线性、非平稳信号,且具有自适应性的数据处理方法．本文简要介绍了一座45层钢筋混凝土框架结构及其振动台试验模型概况. 利用HHT分析了模型结构在不同烈度地震中的反应记录,得到了Hilbert时频幅值三维分布和Hilbert边际谱．Hilbert谱得到记录能量集中分布的频段与时间范围,捕捉到信号变化的主要特征. Hilbert边际谱曲线形状和峰值频率值随着地震烈度的升级而发生了相应变化,而且所有的结果图形体现出相同的规律性,预示着Hilbert边际谱在土木工程结构安全评价中的应用前景．   相似文献   

Pseudo-dynamic test and numerical simulation of high-strength concrete frame structure reinforced with high-strength rebars     

Xin Chen  Shi Yan  Baojian Ji 《地震工程与工程振动(英文版)》2011,10(2):303-311

This paper describes an investigation of a high-strength concrete frame reinforced with high-strength rebars that was tested in the structure engineering laboratory at Shenyang Jianzhu University. The frame specimen was pseudo- dynamically loaded to indicate three earthquake ground motions of different hazard levels, after which the test specimen was subjected to a pseudo-static loading. This paper focuses on the design, construction and experiment of the test frame and validation of the simulation models. Research shows that a high-strength concrete frame reinforced with high-strength rebars is more eff icient and economical than a traditional reinforced concrete frame structure. In addition to the economies achieved by effective use of materials, research shows that the frame can provide enough strength to exceed conventional reinforced concrete frames and provide acceptable ductility. The test study provides evidence to validate the performance of a high- strength concrete frame designed according to current seismic code provisions. Based on previous test research, a nonlinear FEM analysis is completed by using OpenSees software. The dynamic responses of the frame structure are numerically analyzed. The results of the numerical simulation show that the model can calculate the seismic responses of the frame by OpenSees. At the same time, the test provides additional opportunities to validate the performance of the simulation models.  相似文献   

Investigation of effect of near-fault motions on substandard bridge structures   总被引：1，自引：1，他引：0  

Austin Brown  M. Saiid Saiidi 《地震工程与工程振动(英文版)》2011,10(1):1-11

The objective of this study was to investigate the effects of near-fault ground motions on substandard bridge columns and piers. To accomplish these goals, several large scale reinforced concrete models were constructed and tested on a shake table using near- and far-field ground motion records. Because the input earthquakes for the test models had different characteristics, three different measures were used to evaluate the effect of the input earthquake. These measures are peak shake table acceleration, spectral acceleration at the fundamental period of the test specimens, and the specimen drift ratios. For each measure, force-displacement relationships, strains, curvatures, drift ratios, and visual damage were evaluated. Results showed that regardless of the measure of input or response, the near-fault record generally led to larger strains, curvatures, and drift ratios. Furthermore, residual displacements were small compared to those for columns meeting current seismic code requirements.  相似文献