小江断裂带中段和南段井水位变化与形变分析  

ANALYSIS OF WATER LEVEL CHANGES AND DEFORMATION PROCESS OF THE MIDDLE AND SOUTHERN SEGMENTS OF XIAOJIANG FAULT ZONE

作　　者：唐彦东[1,2] 刘春平[2] 廖欣[2] 石云[1,2] 万飞[2] 

机构地区：[1]湖南师范大学资源与环境科学学院,长沙410005 [2]防灾科技学院,河北三河065201

出　　处：《地震地质》2013年第3期553-564,共12页Seismology and Geology

基　　金：中国地震局教师科研基金(20100104;20130102)资助

摘　　要：应用井孔-裂隙、微裂隙(孔隙)水流交换产生的潮汐水位-固体潮的位相差和振幅变化理论,结合井水位变化,分析小江断裂带中段和南段的形变特征。裂隙承压含水层条件下,地震波和构造应力引起的形变能够引起潮汐水位分波位相差和振幅的变化。地震波引起含水层与井孔之间水流交换增大,疏通裂隙而使渗透率增大,震后井水位潮汐分波相位差提前,其后裂隙内沉积物重新堵塞裂隙,渗透率降低,位相差逐渐下降。位相差的长期趋势性变化反映出含水层在构造应力作用下的应变信息。小江断裂带中段和南段形变变化不同。断裂带中段地区,观测井位相差和振幅趋势性下降,表明该区段不仅有走滑特性,并且具有挤压特征。小江断裂带与红河断裂带交会地区观测井振幅和位相差稳定,表明该区域没有受到明显的挤压,形变不明显。This paper analyses the deformations of middle and southern segments of Xiaojiang Fault zone u- sing the theory of phase shift and amplitude changes between tidal water level and earth tides caused by water exchange among the systems of well hole-fracture-micro fracture. Seismic waves and deform- ation caused by tectonic stress can lead to changes of phases shift and amplitudes of tide levels in frac- tured confined aquifer. Seismic waves can increase water exchange between the aquifer and the bore- hole. So the fluid pathways can be unclogged during the earthquake and permeability in the fractured rock system can be increased after the earthquake. Smaller phase shift lag implies the higher permea- bility in the system. Permeability will return to background value gradually because of reclogging of fluid pathways and phase shift decreases. The long-term trend of phase shift represents the information of aquifer deformation caused by tectonic stress. The middle and southern segments of Xiaojiang Fault zone deform differently. The middle segment of the fault zone shows both strike-slip and compression characteristics. Deformation of this section is accumulated continuously. Phase shift and amplitude of the monitoring wells located at the intersection of Xiaojiang Fault zone and Honghe Fault zone change in a small scope. This shows that deformation of this section is not obvious and the aquifer is not squeezed remarkably.

关 键 词：振幅 相位差 构造应力 小江断裂带 含水层 

分 类 号：P315.723[天文地球—地震学]