Upper bound limit analysis of roof collapse of deep cavities in unsaturated soils
Upper bound limit analysis of roof collapse of deep cavities in unsaturated soils
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DOI：
10.1002/nag.3343
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发表时间：
2022-02
影响因子：
4
通讯作者：
Yanru Zhao;Xiaojiao Li;P. Tai;Liping Huang;Bo Pu;Rui Chen
中科院分区：
文献类型：
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作者：
Yanru Zhao;Xiaojiao Li;P. Tai;Liping Huang;Bo Pu;Rui Chen
深空腔顶板坍塌只在完全干燥或饱和条件下进行过研究。然而，天然土大部分是非饱和的，因此，由于基质吸力的存在，它们的力学行为有很大的不同。本文基于上界定理和非线性Mohr-Coulomb准则，建立了非饱和土中深部空室顶板坍塌的解析解，并推导了任意形状空室崩塌时的宽度。随后，进行了参数化研究，探讨了保水性、有效黏聚力、摩擦角、支撑压力和非线性系数对矩形深空腔安全系数的影响。研究发现，基质吸力和土体类型对深空腔稳定性有显著影响。当土壤持水能力较低时，随着基质吸力的增加，深孔的安全系数有一个峰值。这种新颖的解析解为非饱和土中深孔洞的稳定性提供了新的认识。
The roof collapse of deep cavities has been investigated only under fully dry or saturated conditions. However, natural soils are largely unsaturated, and consequently, their mechanical behavior is significantly different owing to the presence of matric suction. In this study, a novel analytical solution for the roof collapse of deep cavities in unsaturated soils is developed based on the upper bound theorem and the nonlinear Mohr–Coulomb criterion, and the width of a cavity with an arbitrary shape at collapse is derived. Subsequently, a parametric study is conducted to investigate the effects of water retention properties, effective cohesion, friction angle, supporting pressure, and nonlinear coefficient on the safety factors of rectangular deep cavities. It is found that matric suction and soil type have significant influences on the stability of deep cavities. There is a peak for the safety factors of deep cavities as the matric suction increases when the water‐holding capacity of the soil is low. This novel analytical solution provides a new insight into the stability of deep cavities in unsaturated soils.