Spatial variation of seismic motion induced by propagation of body waves     

D. Zendagui  M. K. Berrah 《Soil Dynamics and Earthquake Engineering》2002,22(9-12):805-811

Spatial variation of earthquake ground motion is an important phenomenon that cannot be ignored in the design and safety of strategic structures. Several models have been developed to describe this variation using statistical, mathematical or physical approaches. The latter approach is not specific to an event. A recent contribution, which uses such an approach and called complete stochastic deamplification approach (CSDA), was developed [1]. The aim of this paper is to analyze the spatial variation of earthquake motion induced by the propagation of body waves using the CSDA. Coherency functions are evaluated for the cases of SH–SV–P waves propagating through stratified soil. Results obtained show that the variation of the coherency function is not the same for vertical and horizontal components and that the motion is more coherent at depth than at the free surface. In fact, we found that the rate of decrease with frequency and distance is not the same if P–SV waves propagate through stratified soil.  相似文献   

Geostatistical inversion of coupled problems: dealing with computational burden and different types of data     

《Journal of Hydrology》2003,281(4):251-264

Practical application of geostatistical inversion to coupled problems is hampered by a number of difficulties. In this paper, we address two of them: first, the computational cost of sensitivity (Jacobian) matrices and, second, the evaluation of the relative weights of different types of data. Regarding the first, we revise the adjoint state equations to propose a form whose cost is independent of the number of unknown parameters and only grows with the number of observation wells. Regarding the second, we derive expressions for the relative weights of different types of data. These expressions are based on minimizing the expected likelihood, rather than the likelihood itself. The efficiency of both improvements is tested on a synthetic example. The example analyzes a wide range of groundwater flow and solute transport conditions. Yet, the expected likelihood consistently yields the optimal weights. The proposed form of the adjoint state equations leads to one order of magnitude reduction in CPU time with respect to the conventional sensitivity equations.  相似文献   

场地条件对地震动相干函数的影响   总被引：3，自引：1，他引：3  

丁海平  金星  刘启方  袁一凡 《地震工程与工程振动》2003,23(1):1-5

本通过弹性半空间内位错源的数值解法研究了曲岩地震动相干函数，采用有限元方法分析了一些典型场地的地表地震动相干函数，两的对比结果表明：复杂场地对地震动相干函数的影响强烈。  相似文献   

ω循环型边界条件          下载免费PDF全文

梅金顺  刘洪 《地球物理学报》2003,46(6):835-841

通过利用预条件共轭梯度法对对称正定Toeplitz 矩阵系统进行分析，重点介绍了一种新的嵌入式预条件矩阵构造方法，证明了以前的预条件矩阵构造方法大都是这种方法的特例.提出了ω循环型边界条件，并将其与普通循环型及螺旋型边界条件作了分析、比较后得到了一种新的边界条件即混合型边界条件.  相似文献   

A coherency function model of ground motion at base rock corresponding to strike-slip fault   总被引：2，自引：0，他引：2  

丁海平  刘启方  金星  袁一凡 《地震学报(英文版)》2004,17(1):64-69

IntroductionEarthquakedamagesurveyandresearchresultshavedemonstratedthatspatialdistributiondifferenceofgroundmotionisoneoftheimportantreasonswhichcausedlongstructure(eglongspanbridge,undergroundpipe)destroy.Thathowtoprovideareasonableinputofgroundmotionfieldforaseismicdesignoflongstructureisaurgentprobleminearthquakeengineeringfield.Atpresent,themethodtostudyspatialvariationofgroundmotionsisadoptingstatisticanalysisbasedondensearrayrecordssuchasSMART-1array,etc,togetcoherencyfunctionofground…  相似文献   

非一致激励条件下工程场地地震动相干函数的数值模拟--Ⅰ分析原理和方法     

李杰  陈原 《地震工程与工程振动》2006,26(1):30-35

本文将随机振动的虚拟激励原理与工程波动理论散射问题的求解方法相结合,建立了开放系统中非一致激励条件下工程场地地震动随机场的数值模拟方法。该方法将随机输入下的波动分析问题转换为多个虚拟激励下的确定性波动分析组合问题,从而可以方便地获得场地波动观测量之间的谱密度矩阵,进而计算给出工程场地的地震动相干函数。本文还用数值模拟的办法对所提出方法的合理性和稳定性进行了探讨。  相似文献   

非球形轴对称粒子光散射的散射矩阵元素展开系数的数值计算     

丁继烈  许丽生 《成都信息工程学院学报》1999,(3)

扼要地介绍了非球形粒子光散射的散射矩阵元素按广义球函数展开的基本理论,以及球形粒子散射矩阵元素间的关系。在此基础上较详细地阐述了计算展开系数的方法以及在程序研制中所遇到的一些问题。最后,对非球形的Ｃｈｅｂｙｓｈｅｖ粒子光散射的散射矩阵元素的展开系数进行了计算,结果表明数值技术和计算的正确性。  相似文献   

空间后交的一种新算法     

黄幼才 《武汉大学学报(信息科学版)》1994,(4)

根据矩阵理论，推导了空间后交的一种新算法．这种方法简单易行，无需线性化，其计算结果、精度与传统方法一致．  相似文献   

成层介质中交流电测井响应   总被引：27，自引：10，他引：27       下载免费PDF全文

张庚骥  汪涵明 《地球物理学报》1995,38(6):840-849

本文给出了纵向成层、径向不均匀介质中轴对称电磁波的反射阵和透射阵的递推公式．用这些阵可以计算交流电测并响应，包括感应测并和深探测电磁波传播测井（ＤＰＴ）．同时还给出了幅度基函数和斜度基函数，它们分别＂支撑＂起结点上函数的幅度和斜度．  相似文献   

相干和方差数据体的算法研究及应用     

陈凤云  杭远  康建林 《物探与化探》2006,30(3):250-253,257

研究了相干数据体的C3算法以及方差数据体算法,编制开发了利用相干和方差数据体技术进行地震资料处理的数据处理系统,利用相干和方差数据体的时间切片和顺层切片来分析相邻道地震信号的相似性,进而探测小断层和分析地质构造。通过对实际资料的分析解释可以看出,相干和方差数据体技术对断层解释是非常有效的,可以提高解释精度,缩短勘探周期。  相似文献