地震作用下黄土暗穴的稳定性  

Stability of loess-hidden hole under earthquake

作　　者：陈立伟[1] 彭建兵[1] 范文[1] 孙萍[1] 

机构地区：[1]长安大学地质工程与测绘学院

出　　处：《长安大学学报（自然科学版）》2007年第6期34-38,共5页Journal of Chang’an University(Natural Science Edition)

基　　金：国家西部交通建设科技项目(200131881213)

摘　　要：黄土高原地区发育的黄土暗穴是一种特殊的不良地质现象,已经成为西部黄土地区公路损坏的主要原因。黄土具有很高的地震易损性,对于暗穴较高发育区的西安—兰州一带,受地震影响比较大。在深入研究黄土暗穴发育特点的基础上,采用有限元法对其在地震力作用下的致塌机理进行了数值模拟,得出了不同洞径及埋深的暗穴在地震荷载作用下的动力响应规律。研究结果表明:地震发生时,往往会引起暗穴顶板的塌落,这种现象并非洞壁土体材料的屈服渐次发展所致,而是由突发性的暗穴结构稳定性丧失引起的。Loess-hidden hole developed in the loess plateau is a kind of unfavorable geological phenomenon, and it has become the main reason causing damage to the highway in western loess region. The loess has the seismic vulnerability. At the loess regions from Xi^an to Lanzhou, the hidden-holes are more developed, the earthquake influence is strong. Through the study on the developmental features of loess hidden hole, this paper analyzes the slumping mechanics by dynamic finite element method. According to the dynamic response results of loess-hidden hole with different diameter and embedded depth, when the earthquake happens, the reason causing the hidden holes＇ roof collapsed is not that the soils become yield gradually, but the structure loses its stability. 3 tabs, 8 figs, 10 refs.

关 键 词：道路工程 黄土暗穴 有限元 地震 稳定性 

分 类 号：U419.4[交通运输工程—道路与铁道工程] P642.26[天文地球—工程地质学]