Research On Surface Settlement Effect Caused By Dewatering For Deep Foundation Pit

The surface settlement caused by dewatering and excavation has been noticed widely. Surface settlement damages the environment and construction badly. It will make the surface and building craze, incline or make the conduit underground disuse (even rupture).Groundwater is shallow in Shenyang. The leading component in aquiferous layer is gravel, whose penetrability is great. And the incidence by dewatering is lager, the research on the similar instance like Shenyang that the hardpan thick and the clay pan missing is lacking in China now. The paper researches the settlement rule in the case of large-scale dewatering in Shenyang's geohydrologic condition.Get the influence radius and some other parameters by dewatering experiment. Programmed to draw settlement surface, and validated it with dewatering experiment.Using the theory of hydraulics and soil mechanics under the assume of one direction seepage, it is discussed that the stress change in the pit caused by dewatering and calculation method of the surface settlement. The paper researches that the soil's density change and seepage caused by dewatering make the effective stress change is the essential reason for surface settlement. The calculation method for settlement is deduced consequently.Then the method is applied to practice foundation pit and compared to the observed value in one example foundation pit, and are in good agreement with the observed results.