抽水作用下先期断裂对地裂缝的影响研究  

INFLUENCE OF PRE-EXISTING FAULT ON GROUND FISSURES DURING PUMPING ACTION

作　　者：蒋臻蔚[1] 彭建兵[1] 王启耀[1,2] 

机构地区：[1]长安大学地质工程与测绘学院,西安710054 [2]长安大学建筑工程学院,西安710061

出　　处：《工程地质学报》2010年第5期651-656,共6页Journal of Engineering Geology

基　　金：国家自然科学基金项目(50908018);国土资源大调查项目(121201064140)

摘　　要：过度抽取地下水和先期存在的断裂构造是西安市地裂缝地质灾害发生的主要原因。作者首先从理论上分析了抽水情况下地裂缝形成的张拉破裂机制、剪切破裂机制和张剪复合破裂机制,并从结构面控制理论分析了先期断裂在地裂缝形成中的控制作用;然后依据比奥三维固结理论,采用FLAC软件建立了西安地裂缝的计算模型,比较了抽水作用时没有先期断裂和地层差异、有先期断裂而没有地层差异、有地层差异而无先期断裂等情况时的地面变形特征,得出抽水作用下,先期断裂对地裂缝的形成及发展具有诱导、隔离和放大的耦合作用,从而得出先期断裂不仅仅只是地裂缝形成的构造基础的结论。Ground-water depletion and pre-existing fault are the main factors that can arouse the ground fissures hazard in Xi′an City.Firstly,the tensile crack mechanism,shear crack mechanism,shear and tensile multiple mechanism of the ground fissures are analyzed in theory.The controlling role of the pre-existing fault on the causes of ground fissures is analyzed using structural plane controlling theory.Then,paper sets up a numerical simulation model with three dimension Biot＇s consolidation theory.Using this model,the displacements of three cases are compared.The three cases are pumping without pre-exsting fault,pumping with pre-existing fault,pumping without pre-existing fault but with stratum difference.The paper finds that the pre-existing fault is not only the tectonic foundation,but also has induction,amplification and segregation functions on the formation and development of the ground fissures.

关 键 词：抽水 地裂缝 耦合作用 数值模拟 

分 类 号：P642[天文地球—工程地质学]