Study Of The Working Characteristics In Deep Foundation Pit Supported By Composite Soil-nailed Wall

Deep foundation pit is a complicated geotechnical engineering which is related to lots of subjects.At present, there are many supporting methods for deep foundation pit. Because the supporting form of composite soil-nailed wall is very flexible and offset the deficiency that general soil-nail support has,it is used more and more comprehensively in practical project. Moreover, most of the deep foundation pit are temporary projects and their duration are very short. As a result people are easy to have fluke mind. So,engineering accident happens frequently. It not only brings huge financial losses,but also brings bad social influence. Therefore, there is a very important value of application in practical projects to study on structure deformation, stress regulation and influencing factors of deep excavation supported by composite soil-nailed wall.This article used the method that combination of theoretical analysis and numerical simulations doing research, based on the engineering background which is called deep foundation pit project of maternal and child care service centre in Jinan. First, studied on the changing rules of pile lateral displacement, ground settlement, basal heave and soil nail's axial force around the deep foundation pit supported by composite soil-nailed wall.And then studied on the influences of pile lateral displacement, ground settlement, basal heave and soil nail's axial force caused by changing the value of soil nail's length, soil nail's inclination, soil nail's interval, pile length, pile elastic modulus, water-resisting curtain thickness and excavation depth. Meanwhile, summarized the regulars of influences about each factor.After that, seriously studied on the connection between soil nail's length, pile elastic modulus, excavation depth and the horizontal displacement on the pile top.Also elicited the computational formula between those three factors and the horizontal displacement on the pile top by means of function fitting.Finally, educed the experience formula with contribution coefficient about how to calculate the horizontal displacement on the pile top of deep foundation pit supported by composite soil-nailed wall and checked the result. This achievement can provide reference basis for design and construction of deep foundation pit supported by composite soil-nailed wall in future. So that we can preferably guide the engineering construction.