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   

依据剖面资料求解断层的水平位移     

安晓文  李世成  周瑞琦  俞维贤  陈宇军 《地震研究》2002,25(4):369-373

提出依据开挖剖面中的楔形体在受到断层作用时其厚度的变化量求解断层水平位移的方法。分析表明断层水平位移量S与楔形体在断层两侧厚度变化量Δh满足关系式S＝Δh/ρsinβ。式中ρ为楔形体在断层走向上的尖灭系数，β为断层的倾角，该关系式不仅能满足纯走滑运动的断层，而且也满足一般斜滑断层，同时提出了在剖面上判断断层水平运动性质的方法。  相似文献   

扁铲侧胀试验判别液化的研究和实践   总被引：8，自引：0，他引：8  

陈国民  李隽毅  汤智青 《上海国土资源》2003,(1):20-24

通过对扁铲侧胀试验判别液化的研究和实践，提出了在上海地区采用扁铲侧胀试验判别液化的公式，扁铲侧胀试验判别液化与标准贯入和静力触探试验判别液化的方法对比，具有相对较好的结果，是一种有前途的液化判别方法。  相似文献   

结构设计地震作用效应影响因素及规律分析   总被引：1，自引：1，他引：1  

李英民  郑妮娜  周长安 《世界地震工程》2003,19(1):51-56

基于现行《建筑抗震设计规范》（GB50011－2001），本文分析了现行抗震设计中影响结构设计地震作用效应的主要因素，以规则平面框架对例对新旧规范影响结构设计地震作用效应的因素进行了对比，给出了其间的重要变化和基本规律。  相似文献   

安塞油田坪桥水平井区沉积微相三维建模研究   总被引：4，自引：0，他引：4  

吴胜和  武军昌  李恕军  吴志宇 《沉积学报》2003,21(2):266-271

以安塞油田坪桥水平井区为例,探讨了应用水平井和露头资料及标点过程(示性点过程)方法进行沉积微相三维建模的思路与方法,同时对研究区三角洲前缘分流河道的定量结构模式进行了深入的研究。研究表明,坪桥水平井区三角洲分流河道单砂体宽度一般为40～100m左右。砂体结构呈两种模式,其一为“迷宫状”,砂体离散地分布于湖相泥岩中,其二为“拼合板状”,多个砂体在侧向上叠置而形成连片分布的砂体,但部分单砂体间可被泥质或钙质薄层侧积层所隔挡。应用水平井资料和露头资料,可有效地提取三维建模所必须的地质统计学参数。研究表明,采用标点过程方法,可建立符合地质实际的沉积微相三维模型。  相似文献   

Aseismic negative dislocation model and deformation analysis of crustal horizontal movement during 1999——2001 in the northeast margin of Qinghai-Xizang block     

张希 江在森王琪  张晓亮 《地震学报(英文版)》2003,16(4):395-403

Through numerical simulation for GPS data, aseism/c negative dislocation model for crustal horizontal movement during 1999-2001 in the northeast margin of Qinghai-Xizang block is presented, combined with the spatial distri-bution of apparent strain field in this area, the characteristics of motion and deformation of active blocks and their boundary faults, together with the place and intensity of strain accumulation are analyzed. It is shown that: a) 9 active blocks appeared totally clockwise motion from eastward by north to eastward by south. Obvious sinistral strike-slip and NE-NEE relative compressive motion between the blocks separated by Qilianshan-Haiyuan fault zone was discovered; b) 20 fault segments (most of them showed compression) locked the relative motion between blocks to varying degrees, among the total, the mid-east segment of Qilianshan fault (containing the place where it meets Riyueshan-Lajishan fault) and the place where it meets Haiyuan fault and Zhuanglanghe fault, more favored accumulation of strain. Moreover, the region where Riyueshan-Lajishan fault meets north boundary of Qaidam block may have strain accumulation to some degree, c) Obtained magnitude of block velocities and locking of their boundaries were less than relevant results for observation in the period of 1993-1999.  相似文献   

空间点相对关系的精密检测     

田林亚  何江斌  张铎强 《测绘工程》2003,12(2):9-10,40

工业检测的精度一般要求很高，常规的检测手段难以达到。本文对空间点相对关系的精密检测方法和精度进行分析，实践表明该方法行之有效。  相似文献   

黄壁庄水库副坝塌坑Ⅳ76+1槽段安全监测     

曹荣祥  李强  周启 《岩土力学》2003,(Z1)

介绍了黄壁庄水库副坝塌坑Ⅳ76+1槽段进行的安全监测设计及根据此设计进行的安全监测实施,根据取得的监测资料解决了一直未能确定的主要变形地层的问题,为水库的加固施工和后期的运行安全提供了一定的依据。  相似文献   

A STUDY ON TYPHOON MOVEMENT PART Ⅲ:EFFECT OF THE HORIZONTAL MOMENTUM EXCHANGE BETWEEN TYPHOONS AND ENVIRONMENT     

贺海晏  董惠菁 《热带气象学报(英文版)》1997,3(1):1-10

Two semi-asymmetric flow patterns of typhoons are chosen to qualitatively determine the effect of exchange of horizontal momentum between inflow and outflow layers and the environment on the motion of typhoons. The results show that only the asymmetric flow component (residual after azimuthal mean flow has been removed) could cause a net momentum input into or output from a typhoon and therefore contribute to the changes in speed and direction of the typhoon movement. A typhoon with major inflow and/or outflow channels on its right (left) side would tend to accelerate and turn left (decelerate and turn right); On the other hand, a typhoon with major inflow and/or outflow channels in the rear (front) semicircle would tend to accelerate and turn right (decelerate and turn left).  相似文献   

Recovering magnetic susceptibility from electromagnetic data over a one-dimensional earth   总被引：1，自引：0，他引：1  

Zhiyi Zhang  Douglas W. Oldenburg 《Geophysical Journal International》1997,130(2):422-434

While the inversion of electromagnetic data to recover electrical conductivity has received much attention, the inversion of those data to recover magnetic susceptibility has not been fully studied. In this paper we invert frequency-domain electromagnetic (EM) data from a horizontal coplanar system to recover a 1-D distribution of magnetic susceptibility under the assumption that the electrical conductivity is known. The inversion is carried out by dividing the earth into layers of constant susceptibility and minimizing an objective function of the susceptibility subject to fitting the data. An adjoint Green's function solution is used in the calculation of sensitivities, and it is apparent that the sensitivity problem is driven by three sources. One of the sources is the scaled electric field in the layer of interest, and the other two, related to effective magnetic charges, are located at the upper and lower boundaries of the layer. These charges give rise to a frequency-independent term in the sensitivities. Because different frequencies penetrate to different depths in the earth, the EM data contain inherent information about the depth distribution of susceptibility. This contrasts with static field measurements, which can be reproduced by a surface layer of magnetization. We illustrate the effectiveness of the inversion algorithm on synthetic and field data and show also the importance of knowing the background conductivity. In practical circumstances, where there is no a priori information about conductivity distribution, a simultaneous inversion of EM data to recover both electrical conductivity and susceptibility will be required.  相似文献