Deformation Prediction And Numerical Analysis Of Foundation Pit's Excavation

In recent years,with the continuous development of C hina's society,the population is becoming more and more concentrated and the development scale of the city has also been increasing,which makes the scarce land resources less.Some cities are located in river valleys,mountain areas and other areas which are restricted by topographic conditions,so urban land resources are scarcer.In order to save land resources and improve the utilization of land resources,urban transportation and construction and ot her facilities are expanding into the air and underground.Develop the space of air and underground must involves the foundation pit problem.In the design and construction of the foundation pit,the complexity of the foundation pit can cause serious accide nts.So,during the excavation of foundation pit,we must monitor the deformation of the foundation pit to discover dangerous situations.Deformation monitoring points of foundation pit should be set up first.Based on consideration of economic problem,we can set less deformation monitoring points in the place where the deformation is stable and set more deformation monitoring points in the place where the deformation is unstable.The deformation in the different stages of the foundation pit may be different,so it is possible to increase or decrease the deformation monitoring points.Therefore,it is meaningful to carry out numerical simulation analysis to foundation pit,with the physical truth of foundation pit.This paper takes the data of a foundation pit as an example and finish the following works:(1)Reading a lot of literature,summarizing the common types and reasons of foundation pit's deformation.(2)Introducing the foundation pit used in this paper,including the geological data and supporting structure.Showing a part of the deformation monitoring data.(3)Using Moving Average Method,Exponential Smoothing Method,and Grey Forecast Model to forecast the pile head horizontal displacement of GW1.Finding that Moving Average Method and Exponential Smoothing Method exist hysteresis phenomenon.The result of Grey Forecast Model is unsatisfactory.Raising the Trend Analysis Method on the basis of regression analysis to forecast the pile head horizontal displacement.The result is satisfactory(4)The methods we talked about have some problems that they need some data which has already exist.When setting up the deformation monitoring points,we need to know the overall deformation of foundation pit.Carrying out numerical analysis to foundation pit and compare the predicted results with the actual results,finding that numerical analysis can provide effective reference to the design of foundation pit's deformation monitoring scheme and the layout of foundation pit's deformation monitoring point.