突发地质灾害中应急数值模拟技术应用浅析

摘要

以滑坡为例，通过综合分析大量前人研究成果，阐述数值模拟在常规状态地质灾害稳定性分析、滑坡机制分析和滑动过程推演中的应用状况，总结数值模拟技术应用于地质灾害应急的基础，比较常规状态和应急情境下数值模拟技术条件的区别，明确应急数值模拟过程特点，提出应急数值模拟技术关键问题。最后，以峨眉山九里镇王山—抓口寺滑坡灾情为例，结合非连续变形分析方法（DDA）大变形和真实时间模拟的优势，进一步研究了数值模拟在灾情应急过程中启动原因和滑动过程反演的实际应用。结果表明，滑体滑动过程中最大水平位移约87m，峰值速度7m·s－1，滑距约38m，前缘堆积厚度53m，滑坡滑动过程持续时间70s左右，与应急调查结果相符。模拟结果有助于理解滑坡发生机制，有助于确立滑坡应急防治重点，辅助应急决策效果明显。%This paper is based on the analysis of landslide and a large number of predecessor research results.It summarizes the works of conventional numerical simulation in the analysis of stability,landslide mechanism analysis and reproducing sliding process.It presents the basic conditions of numerical simulation applicable to geo-hazard emergent rescuing.At the same time,it puts forward the state differences between conventional and emergency numerical analyses.It clearly figures out the characteristics of emergency numerical simulation,and the key problems about the application of numerical simulation to geo-hazard emergent rescuing.It gives an application example of the Wangshan-Zhuakousi landslide on the Mount Emei,Sichuan province.It uses the numerical method of discontinuous deformation analysis(DDA)that has outstanding advantages in the analysis of large deformation in real time.The numerical simulation in the process and reason of the landslide have been taken into a further study. The results show,the sliding process is successfully reproduced and the maximum horizontal displacement of the sliding body reached by DDA mode is 87meters.The peak speed is 7m·s-1 .The results show that sliding distance is about 38meters and the leading edge thickness is 53meters.The whole duration of the landslide obtained by DDA method is about 70 seconds.The numerical results are consistent with the results of emergent investigation.It’s concluded that numerical simulation in geo-hazard emergency is good for the comprehension of the process of landslide,finding the key point and auxiliary emergency decision.