潜蚀土拱塌陷流固耦合数值模拟研究  

Numerical Simulation Study on Fluid-Solid Coupling of Submerged Soil Arch Collapse

作　　者：张磊[1] 向喜琼[1] 刘宏[1] 李麟玮 王文俊 ZHANG Lei;XIANG Xiqiong;LIU Hong;LI Linwei;WANG Wenjun(College of Resources and Environmental Engineering,Key Laboratory of Karst Georesources and Environment(Guizhou University),Ministry of Education,Guiyang 550025)

机构地区：[1]贵州大学资源与环境工程学院,喀斯特地质资源与环境教育部重点实验室(贵州大学),贵阳550025

出　　处：《土工基础》2024年第6期1027-1032,共6页Soil Engineering and Foundation

基　　金：国家重点研发计划(2022YFC300330)。

摘　　要：红黏土自上而下透水性差,天然条件下很难发生潜蚀土拱现象。地下水的反复升降增强岩土界面侵蚀作用,红黏土内部的黏土矿物遇水崩解,极易形成局部掉块促进土拱发育,土体结构随之破坏,内部结构的不稳定为潜蚀提供条件,最终诱发潜蚀土拱塌陷。为揭示该塌陷类型发育过程,结合黔南荔波洞丢近年来发生的典型塌陷实例,采用Geo-Studio数值模拟软件,将地下水侵蚀过程简化为开挖,探讨岩溶区浅埋覆盖层红黏土内部发育的土拱塌陷致塌过程。结果表明:地下水侵蚀直接影响覆盖层渗流场、应力场,导致覆盖层局部应力集中、渗流场变化;渗流过程中,有效应力降低导致覆盖层在自身重力作用下局部位移增大,土体结构不稳定加快了潜蚀作用发展,最终诱发塌陷。The red clay has poor permeability from top to bottom,making it difficult for suffusion-induced soil arch phenomena to occur naturally.The repeated rise and fall of groundwater enhance the erosion at the rock-soil interface,causing the clay minerals within the red clay to disintegrate upon contact with water.This easily leads to the formation of localized blocks,promoting the development of soil arches,disrupting the soil structure,and providing conditions for suffusion due to the instability of the internal structure,ultimately leading to the collapse of the suffusion-induced soil arches.To elucidate the development process of this collapse type,this study combines typical collapse incidents in recent years at Dongdiu,Libo,Qiannan.By utilizing the Geo-Studio numerical simulation software,the study simplifies the groundwater erosion process as excavation to investigate the process of red clay suffusion-induced collapse in the shallow buried cover layers in karst regions.The results indicate that groundwater erosion directly impacts the seepage field and stress field of the cover layer,leading to localized stress concentration and changes in the seepage field.During seepage,the reduction in effective stress results in an increase in localized displacement of the cover layer under its own gravity,accelerating the instability of the soil structure,and promoting the development of suffusion,ultimately leading to collapse.

关 键 词：岩溶塌陷 潜蚀 土拱 数值模拟 

分 类 号：P642[天文地球—工程地质学]