摘要
软土地区深基坑支护工程是一项复杂、安全性要求高的工程.在沿海地区,地下水位高,淤泥质土层厚,深基坑支护工程的风险更大.为了研究深基坑开挖之前实施长时间基坑降水对软土地区深基坑工程稳定性的作用效果,在天津市某深基坑工程开挖之前,进行了为期60 d的基坑降水,并在基坑降水过程中的不同阶段进行了现场钻探取土及室内土工试验,分析了土体物理力学指标的变化情况.试验结果表明:基坑长期降水可以提高软土的压缩模量、内摩擦角和粘聚力,改善软土的软硬状态.有限元计算结果显示:开挖前长期降水对提高软土地区深基坑的稳定性、减小支护结构变形具有良好的作用效果.
Deep foundation pit in soft soil area is complex and required high security.In littoral,risk of deep foundation pit is great when the water table is high and mucky soil is thick.In order to study long-term dewatering effect before ex-cavation for stability of deep foundatiton pit,dewatering of foundation pit has been done for sixty days in the certain deep foundation pit of Tianjin city.Drilling in situ and test in laboratory are made,and soil parameters are analyzed in the different phase of dewatering.The test results indicate that constrained modulus,internal friction angle and cohesion of soft soil are heightened and plasticity of soft soil is improved after long-term dewatering.The finite element caculation shows that the stability of deep foundation pit is advanced and protecting structure demermation is minished because of long-term dewatering before excavation.
出处
《河北工业大学学报》
CAS
北大核心
2011年第1期97-100,共4页
Journal of Hebei University of Technology
关键词
深基坑
软土
降水
deep foundation pit
soft soil
dewatering
