Analysis And Application Of Factors Influencing Sliding Resistance Of Thin-walled Light Rail Sliding Retaining Wall

Scholars at home and abroad have studied many common anti-skid structures,such as micro-pile,retaining wall and pile wall composite structure,but few researches on rail anti-skid retaining wall.As a new type of retaining and anti-skid structure,the rail anti-skid retaining wall is mainly composed of rail anti-skid pile and retaining wall.The rail pile is placed vertically,the pile body is connected to the retaining wall,and the lower part is mixed with grout and anchored in the stable soil layer.Compared with the traditional rail pile and retaining wall structure,it has the advantages of simple process,convenient construction and strong anti-sliding ability,but at present,there is no mature and complete theory in the systematic research.In the design of rail anti-skid retaining wall structure,in addition to meeting the requirements of slope sliding force,it is also important to deal with the force between rail and retaining wall,and to better play the functional and economic requirements of the structure.In this paper,with the help of ABAQUS finite element numerical simulation software,the influence of the general parameter variables on the anti-slip ability of the rail anti-slip retaining wall in the slope is discussed.By establishing the mechanics model of the thin-walled light rail anti-skid retaining wall,the stress balance analysis of the rail anti-skid retaining wall structure is carried out,and the stress relationship between each part of the rail anti-skid retaining wall is described in detail.Based on the characteristics of the stress of the pile bending moment and the comprehensive characteristics of deformation of retaining wall slope body bottom rail pile length to carry on the design and adjustment,improper pile length is decorated,the contact area between retaining wall and pile stress concentration phenomenon will expand,may affect the normal use of the feature,easy to produce stress phenomenon mainly distributed in the retaining wall and pile on the top of the junction and boundaries of piles and soil.When there are many rows of piles in the rail anti-skid retaining wall,the soil flow around the piles is not considered much in the analysis,and the calculation formula of pile spacing is derived.The anchor depth of the rail should fully consider the soil characteristics of the strata in the anchor section,and the anchor depth can be preliminarily determined according to the empirical formula.In the soft rock layer,the anchor depth of the lower part of the retaining wall is generally 1/3～1/2 of the total pile length,and in the hard rock layer,the anchor depth of the lower part of the retaining wall is generally1/4 of the total pile length.The finite element software ABAQUS is used to select several factors affecting the skid resistance of the rail retaining wall,establish a three-dimensional numerical model of the slope,and draw the following conclusions:(1)The different pile types of the rails in the rail skid resistance retaining wall have different skid resistance.The influence of 24# and 30# rails as well as 38# and 43# rails on the skid resistance of the rail skid resistance retaining wall in the slope is similar.(2)Compared with the selection of the concrete grade of the retaining wall,the selection of the rail has a greater influence on the sliding force of the rail anti-skid retaining wall;(3)When the lower rail of the retaining wall is anchored in the homogeneous soil layer,the anti-sliding force of the rail anti-skid retaining wall is the maximum when the pile length below the retaining wall is 1/2 of the total pile length;(4)When the soil below the retaining wall is divided into homogeneous soil and stable soil,the maximum anti-sliding force of the rail anti-skid retaining wall is obtained when the length of the pile anchored into the stable foundation soil is 3/4-5/4 of the length of the pile inside the homogeneous soil above it.(5)When multiple rows of piles are set in the rail skid-resistant retaining wall structure,the pile diameter ratio S/D should be set as 5 or6;(6)In the design of rail anti-skid retaining wall,it is appropriate to extend into the retaining wall internal pile length is 4/9～5/9 of the height of the retaining wall.Selection in a national highway as below on the right side slope engineering cases,the original design of the slope treatment project points within the slope displacement and slope safety coefficient calculation,according to rail against sliding retaining wall optimization proposals put forward new governance plan,and to check the stability of the slope of governance,through scheme comparison before and after,It is found that the rail anti-skid retaining wall structure not only saves the project cost of about 170,000 yuan,but also greatly improves the anti-skid force of the anti-skid structure and increases the stability of the whole slope.