水位波动条件下岩溶土洞塌陷的模型试验  

Model test of karst soil cave collapse under water level fluctuation

作　　者：张晓宸 陈学军[1,2] 唐灵明 杨鑫 班如龙 宋宇[1,2] ZHANG Xiao-chen;CHEN Xue-jun;TANG Ling-ming;YANG Xin;BAN Ru-long;SONG Yu(College of Civil and Architecture Engineering,Guilin University of Technology,Guilin 541004,China;Guangxi Key Laboratory of Geomechanics and Geotechnical Engineering,Guilin University of Technology,Guilin 541004,China;Guangxi Normal University,Guilin 541004,China)

机构地区：[1]桂林理工大学土木与建筑工程学院,广西桂林541004 [2]桂林理工大学广西岩土力学与工程重点实验室,广西桂林541004 [3]广西师范大学,广西桂林541004

出　　处：《桂林理工大学学报》2022年第3期593-599,共7页Journal of Guilin University of Technology

基　　金：国家自然科学基金项目(41967037)。

摘　　要：强降雨条件下水位发生剧烈波动,容易触发岩溶塌陷。选取桂林市临桂区作为研究区域,通过现场勘查和理论分析,根据实际情况进行了强降雨条件下两种水位波动情况的土洞塌陷试验,旨在通过研究土洞顶板的孔隙水压力、土压力以及洞室气压的变化,揭示土洞的扩展过程及塌陷机理。结果表明:孔隙水压力、土压力以及洞室气压的变化情况随水位波动呈现出明显的规律性,孔压与土压随降雨量的变化具有分层现象,洞室气压的变化大致可分为2个阶段;当连续性降雨时土压单次变化较弱但塌陷发生较快,间歇性降雨时土压单次变化剧烈但塌陷发生较慢;土洞顶板塌陷经历了土体软化阶段、缓慢塌落阶段和快速-整体塌陷阶段,是强降雨诱发水位变动产生的水、气变化,进而引起多种不利因素叠加作用的结果。Karst collapse is easily triggered by violent fluctuation of water level under strong rainfall conditions.Lingui District of Guilin City was selected as the study area.Through field investigation and theoretical analysis,soil cave collapse tests were conducted under two kinds of water level fluctuations after heavy rainfall.This could reveal the expansion process and collapse mechanism of the soil cave by studying the changes of pore water pressure,soil pressure and chamber air pressure on the roof of the soil cave.The results show that the changes in pore water pressure,earth pressure and cavern air pressure show obvious regularity with the fluctuation of water level.The changes in pore pressure and earth pressure have a stratification phenomenon with the change of rainfall.The change of cavern air pressure can be divided into two stages.In continuous rainfall,the single change of earth pressure is weak,but the collapse occurs faster.In intermittent rainfall,the single change of earth pressure is drastic,but the collapse occurs slower.The collapse of the roof of the cavern experiences three stages of soil softening,slow collapse and rapid-overall collapse.Thus the change of water and air is caused by the change of water level induced by heavy rainfall,and results in superposition of many unfavourable factors.

关 键 词：岩溶土洞 塌陷机理 强降雨 模型试验 

分 类 号：P642.254[天文地球—工程地质学]