循环动荷载与地下水动力条件耦合作用下岩溶塌陷动力响应及灾变机理

项目名称： 循环动荷载与地下水动力条件耦合作用下岩溶塌陷动力响应及灾变机理

项目编号： No.41502341

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 地质学

项目作者： 曾斌

作者单位： 中国地质大学（武汉）

项目金额： 18万元

中文摘要： 铁路沿线由于列车振动产生的次生地质灾害以岩溶塌陷最为典型。随着我国铁路建设的高速发展，越来越多的线路穿越了岩溶地区，高速列车常年循环动荷载的振动与地下水位变动引起水（气）压力变化的耦合致塌机理研究，已成为防治岩溶区铁路沿线路基塌陷的核心问题。本项目以浙赣铁路浙江江山段为典型研究区，根据即有勘察资料构建典型覆盖型岩溶地质概化模型；开展列车动荷载引起下伏土层振动参数的现场监测，以及路基周边地下水位在线监测；结合室内实验获取盖层土体物理力学参数及动荷载作用下相关强度参数；在此基础上，基于“非连续介质力学”理论，利用离散元数值模拟方法从系统演化的微观角度，研究“列车循环动荷载持续作用”与“地下水动力条件异常变化”耦合作用下，覆盖型岩溶由连续体到非连续体的动力响应过程、孕灾模式及致塌临界条件。本研究可为覆盖型岩溶区线性工程防灾减灾提供科学依据，同时也可以极大地丰富覆盖型岩溶区塌陷机理的理论研究体系。

中文关键词： 循环动荷载；水动力条件；覆盖型岩溶塌陷；动力响应；灾变机理

英文摘要： Karst collapse is the most typical secondary geological disasters along the railway because of the train vibration. With the rapid development of railway construction in our country, more and more lines crossing in karst area, study on collapse mechanism induced by high speed train perennial cyclic mechanical loading of dynamic load and water (gas) pressure change caused by variation of ground water, has become the core problem of prevention and control subgrade collapse along the railway in karst area. The project takes the Zhejiang-Jiangxi railway which in Zhejiang Jiangshan segment as a typical study area, based on the construction of typical covered karst geological model from survey data; the field monitoring of train induced vibration parameters of the underlying soil, and online monitoring of underground water level under embankment has to be carried out; the soil physical and mechanical parameters and dynamic correlation strength parameters under load by laboratory experiments has to be gotten; then based on the theory of non-continuum mechanics, from the microscopic point view of system evolution, by using the numerical simulation method, research on procedure of covered karst from continuum to the power of non-continuum, disaster mode and collapse critical conditions, under the condition of sustained cyclic train dynamic load coupling with abnormal change of groundwater ”. This study can provide scientific basis for the disaster prevention and mitigation of linear engineering in covered karst area, at the same time also can greatly enrich the theory system of covered karst collapse.

英文关键词： circular dynamic load;hydrodynamic condition;cover karst collapse;dynamic response;failure mechanism