The Interaction Between Sheet-pile Wall And Rock-soil Body And Its Optimization Research Based On The Soil Arching Effect

China is a mountainous country,mountain land accounts for about 2/3 of the national territorial area.The geological structure of the mountain area is complex,and the topography and landscape change greatly.In recent years,with the development of the Western Development Strategy,more and more projects have been built in mountainous region.In many mountainous areas,large quantities of highways,railways,water conservancy,mines and other engineering projects have been launched.In order to meet the needs of engineering construction,the excavation of rock and soil is very necessary,and even can not be avoided,so that lots of artificial side slopes will come into being.Currently,there are a great many measures to support side slope,and sheet-pile wall is a common shoring measures.At present,the sheet-pile wall has been widely used in the reinforcement of various types of side slopes.Although the structure of sheet-pile wall is not too complicated,but its stress mechanism is complex,and because of the lack of systematic summary of this retaining wall,the engineers often rely on their experience to design sheet-pile wall.Therefore,the theoretical research on sheet-pile wall is behind its engineering practice far and away.The sheet-pile wall can prevent the reinforced soil from slumping,mainly rely on the soil arch effect between the two adjacent piles,but the traditional design method of sheet-pile wall dose not take into account the impact of soil arch effect.Many scholars have researched the soil arch effect in slide-resistant pile,however,people's research on the soil arc effect in sheet-pile wall is not too thorough.In view of this,researching the soil arc effect in sheet-pile wall and optimizing sheet-pile wall has significant theoretical importance and engineering value.In this paper,the main study measures are numerical simulation and laboratory model test.Firstly,the writer analyses the soil arch effect in the sheet-pile wall,and introduce the theory about clear distance between two adjacent piles and the theory about breast board's soil pressure,which all base on the theory of soil arch effect.Then,the writer uses ABAQUS,a software of finite element analysis,to research the impact on the soil arch effect in sheet-pile wall and the soil pressure on breast board,which caused by the breast board's location,the shearing strength of soil,the clear distance between two adjacent piles and the roughness of the contact surface of pile and soil respectively.Finally,the writer explores the optimization measure of sheet-pile wall through laboratory model test and numerical simulation.The main conclusions of this paper are as follows:(1)In the case of other factors unchanged,as the soil's internal friction angle increases,the soil pressure acting on breast board gradually decreases,the soil pressure acting on pile gradually increases,the soil arch effect in the sheet-pile wall gradually enhance.As the soil's cohesive force increases,the soil pressure acting on breast board gradually decreases,the soil pressure acting on pile gradually increases,the soil arch effect in the sheet-pile wall gradually strengthens.(2)In the case of other factors unchanged,as the clear distance between two piles increases,the soil arch effect in the sheet-pile wall gradually weakens,and a greater proportion of soil pressure acts on breast board directly.(3)In the case of other factors unchanged,it is conducive to the formation of the friction arch between two adjacent piles to increase the roughness of the contact surface of pile and soil,and it can effectively reduce the soil pressure acting on breast board and increase the pile-board load sharing ratio.(4)In the case of other factors unchanged,we can install an elastic material between the breast board and the pile's flange plate.As the elasticity modulus of the elastic material decreases,the displacement towards the free face of the soil between two adjacent piles gradually increases,the soil arch effect in the sheet-pile wall gradually strengthens,the pile-board load sharing ratio gradually increases,the soil pressure acting on pile gradually increases,the soil pressure acting on breast board gradually decreases.(5)With the increase of the depth along the cantilever section of the pile,the pile-board load sharing ratio gradually decreases,and the displacement of soil relative to the pile becomes smaller and smaller,and the soil arch effect in the sheet-pile wall weakens gradually.