Study On Subgrade Settlement Influenced By Nearby Excavation Dewatering At Jinan West Station Of Beijing-Shanghai High-speed Railway

In the deep excavation construction process, the influence on the settlement of nearby building due to dewatering is always hardly ignored. In this paper, the influence on railway subgrade foundation by the dewatering of excavation engineering of the nearby new construction Jinan west station of Beijing-Shanghai High-speed line is studied. The settlement data of pile foundation subgrade of the high speed railway line are monitored and collected during the whole construction period to analyze the influence on composite foundation due to the dewatering of deep excavation. The settlement of both the top of pile and the soil between plies are recorded. And the construction period includes the following three phases:a) embankment fill period of high speed railway line subgrade construction, and b) preloading period of high speed railway line subgrade construction, and c) excavation engineering of station accessory building. As the conclusion, a general law of the influence on the composite foundation due to the dewatering of nearby deep excavation was summarized in this paper. Corresponding study achievements are presented as follows:(1) Groundwater levels reduce overall carrying capacity relative reduction (such as the extraction of groundwater), resulting in effective stress increase passed by the soil to the pile of negative skin friction causes pile, the pile settlement increase;(2) The impact of precipitation on the settlement of the reinforced area greater than on the underlying layer.(3) Stop precipitation, the water table rose Foundation Rebound cause deformation of composite foundation by elastic deformation and plastic deformation of two parts.(4) Pit precipitation composite foundation settlement, have a greater impact, according to the results of the numerical simulation, with reference to the field test data, and can reach0.1m this magnitude.(5) Composite Foundation adjustable differential settlement, but in the joint between the pile and soil subsidence have significant fluctuations...