外界因素作用易引起城市道路地下空洞破坏，甚至向上发展至地面形成地层塌陷。基于离散元软件对城市道路路基下空洞的发展破坏进行数值模拟，分析空洞规模、埋深、施工振动、空洞周围土性对空洞稳定性的影响。结果表明：道路路面沉降随着空洞埋深的减小和尺寸的增大，均出现先急剧增加后趋于平缓的过程。该曲线的拐点为道路安全性预测的关键点。当空洞与扰动土层相距3 m以内时，必须考虑施工扰动的影响。沉降值随空洞所在土层的黏聚力和摩擦角均近似呈线性变化。该研究从颗粒细观角度揭示了地下空洞发展至路面塌陷的破坏机制，为地下病害研究提供了新方法。%This paper is concerned specifically with a deeper study addressing cavity disease—cavity damage more likely to occur under urban roads due to the external factors and even cause road surface subsidence. The study involves simulating the development and damage of cavity under urban road using distinct element software and analyzing the impact of the cavity size, buried depth, the vibration during construction, the property of soil around the cavity on the stability of the cavity. The study demonstrates that, as a result of the decrease of the cavity depth and the increase of size, the road surface is subjected to the typical subsidence tending to sharply increase, followed by a flat increase, suggesting that the point of inflexion holds the key to the road safety prediction; the occurrence of a 3-m-distance between cavity and disturbed soil necessitates the consideration of the influence of vibration during construction;and sur-face has subsidence value approximate to linear variation due to the cohesive force and the friction angle of soil to which the cavity is exposed. The study offers a new insight into failure mechanism behind the underground cavity and the resulting road surface subsidence thanks to the application of microcosmic an-gle and may provide a novel approach to investigate cavity disease.
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