| As a typical mountainous country,the rugged,difficult-to-use mountains,hills and plateaus account for nearly 70% of the land area in China.Meanwhile,construction land has decreased dramatically after decades of rapid development.In recent years,under the influence of the national economic transformation and development and the “The Belt and Road” strategy,economic development and infrastructure construction increase demand for more construction land,rational use of mountainous land will become an important way to solve the problem of shortage of land resources."The annual production of 2.4 million tons of aluminum hydroxide and600,000 tons of high-precision aluminum sheet with foil of Qi Ya's aluminum industry" is a provincial-level key investment attraction project in Shanxi Province,its planning plant is located in the loess plateau,the “high digging and low filling” scheme was adopted,multi-stage step geo-grid reinforced earth retaining wall was used for filling slope.When designing the reinforcedearth retaining wall,it was found that there are few relevant specifications and researches on the corners of the reinforced earth retaining wall,the deformation characteristics of the corner part are not clear,the relevant specifications of the structural design and construction are not perfect,and few cases and experiences can be used.However,some studies have shown that the corners are prone to have large deformation.Therefore,in order to improve the structural design of the corner part of the reinforced earth retaining wall project and ensure its safety,it is necessary to study the stress and strain characteristics and influencing factors of the corner part.This paper takes the Qiya Project as the studied background,combined with the Natural Science Foundation of Shanxi Province-“Study on force analysis and failure characteristics of non-linear(irregular)reinforced earth retaining wall”,the deformation characteristics and influencing factors of the corner part of reinforced earth retaining wall was studied by numerical simulation methods.The main research contents and conclusions of this paper are as follows:(1)The three-dimensional numerical analysis model of reinforced earth retaining wall was established using the professional numerical analysis software FLAC3 D in geotechnical engineering field,the horizontal and vertical deformation of the corner part and the tensile stress distribution and rupture surface form of the geogrid was studied.The results shows that concentrated deformation will occur at the corner of the reinforced earthretaining wall,the maximum deformation is at the top of the corner,and the deformation is significantly larger than the straight retaining wall due to the special shape of the wall and stress state.(2)the stress and strain laws in the vertical direction are basically same during the corner part and liner part of the reinforced earth retaining wall.Firstly,the horizontal deformation of vertical wall along the height of wall is "bulk belly";secondly,distribution of vertical deformation on the bisector at the top of the wall is a nonlinear negative correlation curve;thirdly,the distribution law of the maximum tensile stress of geogrid is the same;fourthly,The cross-sectional shape of the potential rupture surface is similar to the logarithmic spiral rupture surface.(3)The differences between the stress and strain point between the corner part and the straight part of the reinforced earth retaining wall are as follows: firstly,straight-line reinforced earth retaining wall only has horizontal deformation of vertical wall surface;From the straight part to the corner part,the horizontal deformation is slightly reduced,and the horizontal deformation of the parallel wall surface is gradually increased,and the two are equal at the corner line.Secondly,in the vertical direction,the position of the potential rupture surface at the top of the corner is deeper than the linear retaining wall;in the horizontal direction,the tensile stress distribution of the upper geogrid at the corner is "X" shaped,and the maximum tensile stress is located at the inner edge of the geogrid,which is significantly different from the distribution of theparallel wall of the tensile stress of the geogrid.Thirdly,in the three dimensions,the potential rupture surface of the linear reinforced earth retaining wall is a curved surface extending along the wall,and the potential rupture surface at the corner is a "chair shaped" and intersects the wall surfaces on both sides.(4)Among the factors affecting the deformation of the corner part of the reinforced earth retaining wall,angle between the wall surfaces,slope rate,steps and auxiliary reinforcement all have a significant impact on the deformation and stability of the site,and the rounded corners have nothing to do with the deformation of the corners.As for the corner part of the reinforced earth retaining wall,the deformation can be controlled and the stability of the retaining wall can be improved by reducing the slope rate,adding steps and auxiliary ribs or a combination of these methods(5)The research results of this paper are used to guide the design of reinforced earth retaining wall of "The annual production of 2.4 million tons of aluminum hydroxide and 600,000 tons of high-precision aluminum sheet with foil of Qi Ya's aluminum industry" ? Currently,the project is still in the construction stage.The research conclusions of this paper will be verify by monitoring datas of this project. |
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