摘要
文章针对承压水地层基坑开挖施工易产生突涌灾害问题,考虑基坑围护结构影响,构造提出一种由剪切区与被动区组成的底板突涌破坏机制。同时,假设基坑周边土体满足非线性Mohr-Coulomb破坏准则,并基于塑性上限定理,推导出基坑底板抗突涌临界安全隔水层厚度的理论计算公式与土体破裂面函数表达式。在此基础上,与现有文献方法、室内试验、数值模拟及工程实例结果进行对比分析,验证本文方法的合理性,分析得到不同基坑设计参数、土体强度参数、承压水压力对底板临界安全厚度的影响规律。研究表明:基坑底板所需临界安全厚度随土体剪胀系数、黏聚力、重度、被动区厚度增加而减小,而随开挖宽度、承压水压力及非线性系数增加而增加。研究工作可为承压水地层基坑支护设计与突涌灾害防治提供一定理论参考。
The construction of foundation pit in the confined water stratum is prone to cause base inrush disasters.Considering the influence of the support structure of the foundation pit,this paper proposes an inrush failure mechanism composed of shear zone and passive zone.Meanwhile,the soil mass around the foundation pit is assumed to meet the nonlinear Mohr-Coulomb failure criterion.Then,based on the upper limit theorem of plasticity,the theoretical calculation formula of the critical safety thickness of the foundation pit base and the function expression of soil failure surface are derived.On this basis,the effectiveness of the proposed method is verified by comparing the existing literature results,laboratory test results,numerical simulation results and engineering practice results.The influence rules of different foundation pit design parameters,soil strength parameters and confined water pressure on the critical safety thickness of the base are obtained.The results show that the critical safety thickness of the foundation pit base decreases with the increase of dilatancy coefficient,cohesion,unit weight,and passive-zone thickness,but increases with the increase of excavation width,confined water pressure,and nonlinear coefficient.The research work can provide a certain theoretical reference for support design and inrush disaster prevention in foundation pits with confined water.
作者
王洪涛
宣兆腾
孔令辉
殷允腾
卢昭
Wang Hongtao;Xuan Zhaoteng;Kong Linghui;Yin Yunteng;Lu Zhao(School of Civil Engineering,Shandong Jianzhu University,Jinan 250101,China;Key Laboratory of Building Structural Retrofitting and Underground Space Engineering,Shandong Jianzhu University,Jinan 250101,China;Beijing China Coal Mine Engineering Co.,Ltd.,Beijing 100013,China;Jinan Urban Construction Group,Co.,Ltd.,Jinan 250031,China)
出处
《土木工程学报》
北大核心
2025年第7期77-86,109,共11页
China Civil Engineering Journal
基金
国家自然科学基金(52374093)
中国博士后科学基金资助项目(2022M711314)
山东省自然科学基金(ZR2022ME088)。
