基于破裂度的堆积层滑坡危险性分析方法  

RISK ANALYSIS METHOD OF ACCUMULATED LANDSLIDE BASED ON FRACTURE DEGREE

作　　者：李世海[1] 周东[1] 刘天苹[1] 

机构地区：[1]中国科学院力学研究所,北京100190

出　　处：《岩石力学与工程学报》2013年第S2期3909-3917,共9页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家重点基础研究发展计划(973)项目(2010CB731500)

摘　　要：分析地表裂缝和滑面状态在滑坡灾害形成过程中表现出来的基本特征,建立地表裂缝和地质体内部破坏状态之间的联系。简单介绍基于连续介质力学的离散元法,对具体的、典型的滑坡进行数值模拟,发现数值模拟结果中的地表裂缝和材料强度有某种相关性,并且存在一个地表最大破裂数。同时定义滑面贯穿时对应的破裂数为滑面最大破裂数。提出破裂度的概念,分地表破裂度和滑面破裂度,取值为滑坡相应位置当前破裂数与最大破裂数之比。研究发现,地表破裂度与滑面的贯通有明确的对应关系,可以直接描述地质体的危险程度,并基于此提出破裂度分析滑坡危险性的基本方法。地表破裂度与网格的划分数目、形状等参数的相关性不大。说明基于破裂度和CDEM分析方法判别滑坡体的危险度是可行的。Basic characteristics for development of surface cracks and state of slip surface during landslide disaster is studied,and relationship between surface cracks and internal fracture state is established. Continuum-based discrete element method(CDEM) is briefly introduced. Through simulation of specific and typical landslides with CDEM,relativity of strength and surface cracks is discussed and maximum number of surface cracks is found. Maximum number of slip surface cracks is defined as the number of cracks on slip surface which is already running through. The concept of fracture degree of surface and fracture degree of slip surface are proposed,which are defined as the ratio of current number of cracks to maximum number of cracks on surface and slip surface respectively. Numerical experiments show that there is a specific corresponding relationship between fracture degree of surface and state of slip surface,which could directly describe the risk of a geological body. Result shows that fracture degree does not rely on mesh division when calculation accuracy is guaranteed,which indicates that it is feasible to use this new method based on fracture degree and CDEM to evaluate the risk of a landslide.

关 键 词：工程地质 滑坡 破裂度 地表裂缝 基于连续介质力学的离散元法 

分 类 号：P642.22[天文地球—工程地质学]