城市地面塌陷数值模拟研究

Numerical Simulation Study of Urban Ground Collapse

摘要: 随着城市化进程的加快，城市地面塌陷问题日益严重，对人民生命财产安全构成威胁。本研究旨在通过数值模拟方法，探究城市地面塌陷的机理及其影响因素，以期为地面塌陷的预防和治理提供科学依据。文章通过数值模拟，对局部、整体湿陷性黄土的不同厚度、汽车等附加荷载、黄土层顶部有杂填土层和路基的不同情况进行研究。数值模拟结果表明：在湿陷性黄土地区，当上覆土层为湿陷性黄土层时，无论是局部浸润饱和还是整体浸润饱和，黄土的湿陷沉降均随着黄土厚度的增大而增大；当在湿陷性黄土层上部路面施加交通荷载时，湿陷仍表现为荷载中心沉降大，两侧沉降小。若湿陷性黄土层上覆杂填土层时，浸水饱和后由于不同地层沉降量的差异可能会形成地下空洞，当空洞逐渐积累到一定程度时，可能会导致上覆土体局部突然下沉，产生地面塌陷。

Abstract: With the acceleration of the urbanization process, the problem of urban ground collapse is becoming more and more serious, which poses a threat to people’s lives and property safety. This study aims to explore the mechanism and influencing factors of urban ground collapse through numerical simulation in order to provide a scientific basis for the prevention and treatment of ground collapse. In this paper, the different thicknesses of local and integral collapsible loess, additional loads such as automobiles, and the different conditions of mixed fill and subgrade on top of the loess layer are studied by numerical simulation. The numerical simulation results show that in a collapsible loess area, when the overlying soil is collapsible loess, the collapsible settlement of loess increases with the increase of loess thickness, no matter if it is saturated locally or saturated as a whole. When the traffic load is applied to the upper pavement of the collapsible loess layer, the collapsibility still shows that the center settlement of the load is large, and the settlement on both sides is small. If the collapsible loess layer is covered with a mixed fill soil layer, the underground cavity may be formed after being saturated by water due to the difference in the settlement amount of different strata. When the cavity gradually accumulates to a certain extent, the local subsidence of overlying soil may be suddenly caused, resulting in ground collapse.