软土深基坑勘察技术及实例验证分析

Investigation Technology and Case Verification Analysis of Deep Foundation Pit in Soft Soil

文中结合工程实例,分析了勘查过程中应用的主要技术,对原位试验中的抽水试验进行了详细的研究。结果表明,软土地区深基坑主要勘察技术包括测量测绘技术、钻探技术、原位试验技术及室内试验技术。在原位试验中,抽水试验格外重要,经试验结果统计,得到含黏性土砾砂层的渗透系数变化范围为5.05×10^(-3)~5.64×10^(-3)cm/s,变化范围相对较小,平均值为5.29×10^(-3)cm/s,判断该土层属中等透水性,为基坑支护、降水等提供有效的参数支持。

In order to effectively ensure the survey quality of deep foundation pits in soft soil areas,this paper,based on the basic information of the project,analyzes the main technologies in the survey process,and then carries out a detailed application study of the pumping test in the in-situ test.The results show that the survey of deep foundation pit in soft soil area is extremely important,and the main survey technologies include surveying and mapping technology,drilling technology,in-situ test technology and indoor test technology;In the in-situ test,the pumping test is particularly important.According to the statistics of the test results,the variation range of the permeability coefficient of the sand layer containing cohesive soil gravel is 5.05×10^(-3)cm/s~5.64×10^(-3)cm/s,relatively small range of variation,with an average value of 5.29×10^(-3)cm/s,it is judged that the soil layer is of medium permeability,providing effective parameter support for foundation pit support.