基坑工程降水引发的环境问题及对策

Environmental Problems and Countermeasures Caused by Ground Water Pumping during Excavation

基坑工程开挖降水势必引起基坑周围土体内地下水位变化和应力场改变,导致周围土体及建筑环境的变形,对周围环境产生不同程度的影响.基坑工程的环境效应包括支护结构、工程桩施工、降低地下水位、土方开挖等对周围环境的影响,并表现在多方面,基坑开挖降低地下水引起围护结构变形及造成基坑内外土体产生沉降、不均匀沉降和水平位移,可能导致建筑物及市政管线的变形,影响其正常使用,甚至破坏.此外,大量被抽取的地下水往往直接排至下水管网,是对城市水资源的巨大浪费.在对问题分析的基础上研究讨论了相关对策.

Construction pit excavation and ground water pumping will inevitably lead to the change of surrounding groundwater level and surrounding soil stress field, and the deformation of surrounding soil and building, more or less impacting the environment of foundation pit. The environmental effects of foundation pit, which performance in many aspects, are impacting on supporting structure, the pile construction, lowering the water table and earth excavation. Excavation and lowering groundwater will cause the deformation of supporting structure, and the settlement, uneven settlement or horizontal displacement of soil inside and outside excavation pit, which maybe lead to the deformation of municipal pipelines and buildings, which can affect their normal use, or even damage them. In addition, urban water resources is wasted because a large amount of groundwater was often discharged directly to the next pipe network. For those, countermeasures were discussed.