南水北调西线一期工程区断层活动性及其对工程的影响分析

FAULT ACTIVITY AND ITS EFFECT ON THE WEST LINE OF WATER DIVERSION PROJECT FROM SOUTH TO NORTH OF CHINA

基于对南水北调西线一期工程区活动断层及其工程效应和遥感解译的2次现场考察工作,提出如下初步认识:(1) 工程区NW向断层的活动方式以左旋走滑为主;近SN向的横向断层较为发育,并多为右旋运动。(2) 由于马尔康基底隆起和年保花岗岩体的遏制作用,断层的活动性表现出自NW向SE减弱的趋势。清水河北断层等区域性断层活动性及其对工程的影响为向区内减弱或趋于终止。(3) 断层活动性对工程的影响主要表现为断层及断层带的变形、断层活动构造应力场对深埋长隧洞的影响,以及对水库诱发地震的影响。

Based on field investigations of fault activity in the project region of the first stage of the west line of Water Diversion Project from South to North of China,following viewpoints are presented. (1) The NW directional faults mainly twist laevogyrately,and the SN directional ones are well developed and twist dextrorsely. (2) Because of the confining of Maerkang floor boming and Nianbao granite,the activity of faults shows a weakening trend towards SE direction. The activity and its engineering effect of regional faults such as Qingshuihebei fault present a trend of weakening,or a tend to terminating. (3) The influences of fault activity on the project are mainly the influences of the deformation of faults and fault belt and tectonic stress field on the deep tunnels,and the influences of fault on the earthquake induced by reservoir.