基坑开挖中地下水抽取对周围环境的影响分析  

Impact Analysis of Groundwater Withdrawal During Excavation of a Deep Foundation Pit

作　　者：唐翠萍[1] 许烨霜[1] 沈水龙[1] 王敏华 

机构地区：[1]上海交通大学土木工程系,上海200030 [2]上海市建筑科学研究院有限公司,上海200030

出　　处：《地下空间与工程学报》2005年第4期634-637,共4页Chinese Journal of Underground Space and Engineering

摘　　要：深基坑工程中,地下水的渗流将会使基坑周围形成降水漏斗。随着开挖的进行,地下水自由面不断下降,从而使坑外土体的有效应力增加,墙后土体将发生不均匀沉降。为分析基坑开挖过程中,周围土体的沉降及地下水位的变化,对基坑建立三维有限元分析模型,这是一个地下水渗流与地面沉降计算的一体化模型。利用该模型分析了在软土地区深基坑开挖引起地下水渗流场的变化。结果表明,地下水头计算值与工程现场的实测值吻合,此方法可以较好的模拟实际工程。还用该模型分析了基坑开挖地下水抽取引起的地面沉降问题。During the excavation of deep foundation pit, the seepage of groundwater forms a drawdown cone around the foundation pit. Drawdown of the groundwater level will cause the increase of effective stress of soil outside the pit. Thus, the soft clay will be consolidated and settlement will occur around the pit. In order to analyze the variations of groundwater level and ground surface settlement during excavation, a 3D finite element model was established. It is an integrative model by considering the groundwater seepage and calculation of ground settlement in one process. This model is used to analyze the changes of groundwater seepage zone due to the deep excavation in soft soil. The results indicate that the calculated value of groundwater head is consistent with the field measurement value. Therefore, this method can be used to simulate the practical engineering well work. Meanwhile, the model is also used to calculate the ground surface settlement induced by the withdrawal of groundwater.

关 键 词：深基坑开挖 地下水抽取 三维有限元分析 地面沉降 

分 类 号：TU473.2[建筑科学—结构工程] TU46+2[建筑科学—土工工程]