Earthquake—generating Structure Revealed by 1999 Sichuan mianzhu Earthquake Sequence with Ms=5.0

Through the accurate determination of hypocenter location,the measurement of the main focal mechanism solutions and the analyses of time dependent processes for Sichuan Mianzhu earthquake sequence with Ms=5.0 occurred along the middle segment of Longmenshan fault zone on November 30,1999,the distribution of focal depth section,the stress relase and seismicity features are given to reveal the earthquake-geneating structure of the earthquake sequence.The obtained results show the activity features for this sequence as follows:(1) There is no obvious foreshock,the accumulated strain energy releases in nearly pulse way,fluctuation of the seismic activity level is not quite evident during the duration of the sequence,and the statistical relation between the large events and the small events is less compatible with the traditional G-R estimation;(2) The epicenters of the earthquake sequence are not distributed on the main Longmenshan piedmont faults emerging out ground,but near the hidden Longmenshan piedmont faults.The direction of epicenter distribution is not very coincident with the fault strikes.The microscopic epicenters are relatively far from the macroscopic epicenters,The focal depths range from 5km to 16km;(3) The fractures of focal fault plane with the NE strike appear out the strike-slip displacement with a few overthrust components under the major principal compressive stress of NNE direction.From these,we consider it should be paid more attentions to the underground hidden faults near the ground fault zone on a large scale for their generating earthquake risk.     

Focal Fault of the 1999 Datong Ms5.6 Earthquake in Shanxi Province

Several earthquakes with Ms≥5.0 occurred in the Datong seismic region in 1989,1991 and 1999,The precise focus location of the earthquake sequence was made by the records of the remote sensing seismic station network in Datong.Using that data together with macro-intensity distribution and focal mechanism solutions,we analyze the difference among three subsequences.The results show that the focal fault of the 1999 Ms 5.6 earthquake was a NWW-trending left-lateral strike-slip fault.It is 16km long and 12km wide.It developed at the depth of 5km and is nearly vertical in dip.The two previous earthquake subsequences,however,were generated by activity along NNE-trending right-lateral strike-slip fault.It can be found that the rupture directioin of the 1999 earthquake has changed.It is generally found that a rupture zone has more than two directions and has different strength along these two directions.The complicate degree of focal circumstance is related to the type of earthquake sequences.There is the NE-trending Dawangcun fault and the NW-trending Tuanbu fault in the seismic region,but no proof indicates a connection between focal faults and these two tectonic faults.The feature that focal faults of three subsequences are strike-slip is different from that of the two tectonic faults.It is suggested that the 1999 earthquake subsequence was possibly generated by a new rupture.     

不同小波基下的结构位移反应动力可靠性分析

本文从三种不同小波即：修正的Meyer小波，littlewood-Paley小波，谐波小波的基本概念出发，得出这三种小波基下的地震输入瞬时功率谱，并求出在地震作用下各自的结构位移反应瞬时功率谱，同时定量给出了在这三种小波基下的自由度体系结构位移反应的动力可靠度时程。     

跨断层长输油(气)管道抗震研究与实践

概述了输油（气）管道跨断层抗震研究与实践的现状，总结了判断地表断裂位移的两种经验统计方法和覆盖土层场地地表断裂的分析判断方法，评述了用这些方法得到的结果。对常用的跨断层管道抗震分析方法进行了评述，并列举了我国管道工程中可行的抗震措施。     

位移监测在滑坡时空运动研究中的应用

滑坡时空运动特征是滑坡地质体在内因和外因共同作用下，自一种状态向另一种状态转化的地质过程。滑坡位移监测是研究滑坡变形影响因素、动态规律及预测预报的主要途径，特别是滑坡深部位移监测，又为研究滑坡体的时空运动过程提供了重要信息。本文结合几个滑坡的深部位移监测实践，综合分析位移监测信息，研究滑坡体的时空运动特征及发展趋势，为滑坡时空运动系统研究及稳定性预测提供依据。     

贵州雷公山背斜南段锑矿控矿条件浅析

本文根据雷公山背斜南段的几个锑矿床的勘查资料，结合1：5万区调和相应的科研成果，总结该区锑矿床的共同特征，并对其控矿条件进行分析，认为逆冲断层、剪切带控制锑矿田的分布，“褶皱 断层”控制锑矿床分布，单条剪切带及后期脆性断层控制锑矿体的产出。     

支挡结构位移与土体应力相互作用研究

通过现场监测数据分析 ,获得了在复杂地层中在支挡结构水平位移达到一定值时 ,淤泥质亚粘土层中有效应力会有突然增大的现象 ,为今后深基坑工程设计提供了一种土压力取值的依据。     

直埋敷设热力管道取消固定支座的可行性

本文从热力管道直埋敷设的固定支座功能出发，分析了取消固定支座后管道的状况及应力分布，讨论了取消固定支座以提高设计的科学性，节省资金的可能性。     

多右端非对称位移方程组的GMRES种子投影方法

考虑用GMRES方法求解多右端非对称位移方程组(A-σjI)x^(j)=b^(j)，1≤j≤p。基于Smith的求解多右端方程组的种子投影思想，提出了求解上述位移方程组的GMRES种子投影方法，利用种子方程组产生的Krylov子空间来求近似解。本文给出了近似解的误差界，最后数值结果显示了该方法的有效性。