地形偏压作用下渗流诱发地表塌陷模型试验  

Model Test of Surface Collapse Induced by Seepage under Topographic Bias

作　　者：黎诗诚 苏永华[1] 尹文杰 王晓波 Li Shicheng;Su Yonghua;Yin Wenjie;Wang Xiaobo(College of Civil Engineering,Hunan University,Changsha 410082,P.R.China)

机构地区：[1]湖南大学土木工程学院,长沙410082

出　　处：《地下空间与工程学报》2024年第1期133-142,共10页Chinese Journal of Underground Space and Engineering

基　　金：国家自然科学基金(52178330,51878266)。

摘　　要：目前尚缺乏对地形偏压作用下渗流诱发地表塌陷的发育和影响机理的研究,本文采用自行设计的模型,以坡度倾角为主变量,结合填土高度、相对密实度以及含水率多个变量开展了对照试验。通过对试验结果的分析,获取了塌陷发育过程的规律以及不同因素作用下对地表塌陷的影响机理。结果表明:级配良好的砂土塌陷过程可分为缓慢侵蚀、加速侵蚀和塌陷阶段;沉降槽中心位置随着坡度倾角增大向深埋侧移动,空腔面积的扩展速率随倾角增大而增大;含水率影响土的基质吸力和抗剪强度,使空腔面积扩展速率与含水率成反比,沉降槽中心位置偏移角度随含水率增大而增大,塌陷坑形状也随含水率改变有显著差异;随着砂土的相对密实度增大,塌陷范围有减小的趋势。In view of the lack of research on the development and impact mechanism of surface collapse induced by seepage under terrain bias,in this paper,a self-designed model was used to carry out a control test with slope angle as the master variable and several variables including fill height,relative density and water content.Through the analysis of the test results,the law of subsidence development process and the influence mechanism of the surface subsidence under the action of different factors are obtained.The test results show that the collapse process of well-graded sand can be divided into slow erosion stage,accelerated erosion stage and collapse stage;the center position of the settlement tank moves to the deeply buried side with the increase of the slope angle,and the expansion rate of cavity area increases with the increase of the angle.The water content affects the suction of the matrix and the shear strength of the soil,so that the expansion rate of cavity area is inversely proportional to the water content,the offset angle of the center position of settlement tank increases with the increase of water content,and the shape of the collapse pit is significantly different with the change of water content.With the increase of relative density,the collapse range has a decreasing trend.

关 键 词：地形偏压 岩溶渗流 地表塌陷 模型试验 影响机理 

分 类 号：TU46[建筑科学—结构工程]