摘要
建立了软土深基坑抗突涌判断的弹塑性有限元数值分析模型,分析承压水位作用下的坑底突涌稳定性与基坑变形性状,并将抗突涌稳定性数值计算结果与现有理论分析方法作比较,验证数值计算的合理性。在此基础上,对影响抗突涌稳定性的承压水头、隔水层厚度、土体强度等因素进行参数分析,探讨围护墙水平位移与坑底回弹隆起的变化规律。分析结果表明:数值计算方法可以考虑坑底隔水层实际受力条件与土体强度对突涌稳定性的影响,较传统方法更为合理。随着承压水头的降低、坑底隔水层厚度的增加与土体抗剪强度的增强,基坑围护墙水平位移与坑底的回弹隆起逐渐减小。工程中应综合考虑采用多种措施,提高深基坑的抗突涌稳定性,达到经济合理的安全措施。
Numerical models of a deep braced foundation pit under confined water were established by elastic -plastic finite element method, the hydraulic heave stability and deformation of retaining wall at different excavation depths and confined water levels were investigated. In addition, the computed stabilities were compared with the existing theoretical analysis method. On this basis, the numerical models of different groundwater level, thickness of clay aquiclude, soil strength and other factors were computed to evaluate horizontal displacement of retaining wall and uplift rebound of the pit bottom. The results illustrate that： the actual force situation and cohesive soil strength of excavation bottom clay aquiclude can be well considered by numerical method, and computed results would be consistent with actual foundation pit stability. Retaining wall horizontal displacement and foundation pit bottom rebound decrease with the decline of confined water level, increase of clay aquiclude thickness and enhancement of soil shear strength. Comprehensive measures should be adopted to improve the hydraulic heave stability of the actual deep foundation pit, achieve economical and reasonable foundation pit security measures.
出处
《结构工程师》
北大核心
2015年第6期129-136,共8页
Structural Engineers
基金
国家自然科学基金青年基金项目(41402270)
江苏省科技计划前瞻性联合研究项目(BY2014108-26)
关键词
深基坑
黏性土
突涌稳定性
参数分析
deep foundation pit； cohesive soil； hydraulic heave stability； parametric analysis
