摘要
利用离心模型试验、Biot固结理论的有限元和现场观测数值相结合的方法,对上海地区⑤-2层浅承压水和⑦层深承压水间的⑥层隔水层的存在或缺失对基坑变形和降水影响的研究表明,承压水隔层将对基坑开挖时的变形产生较大的影响。基坑开挖深度14．4～18 m、承压水位降低4 m 以内、承压水隔层厚度为5．8 m时,承压水隔层缺失将导致地表沉降最大值增加10％～20％,连续墙墙脚水平位移、基底最大隆起增加30％左右。基坑开挖较深时,不能用单一的抗突涌安全系数来控制承压水的降低程度;当承压水隔层缺失时,深层承压水降对浅层承压水位、地面沉降有影响,但影响主要发生在后期。
This paper is mainly concerned with the foundation pit deformation due to dewatering and excavation, in which a separation layer between two layers of confined water exists or not. The results of a centrifuge test and numerical analysis indicate that the existence of separation layer will cause a smaller foundation pit deformation compared with the case without it. If the foundation pit is deep enough, a uniform safety coefficient of piping shouldn＇ t he used, Dewatering of deep confined water will reduce the water level of upper layer and induce deformation of soil, but it will often occur at the late period of dewatering.
出处
《城市轨道交通研究》
2006年第4期22-26,共5页
Urban Mass Transit
关键词
承压水隔层
承压水
基坑降水
基坑变形
抗突涌安全系数
separation layer, confined water, dewatering,foundation pit deformation, safety coefficient of piping
