Stability Analysis Of Integrated Panel Wrapped Reinforced Soil Retaining Wall In Railway Station

Reinforced soil retaining wall has the advantages of convenient construction,economical saving and good stability,and has been widely used in highway,railway and other fields.The research on the force deformation characteristics and stability of double-stage reinforced retaining wall is not in-depth at present and the research on the integral panel wrapped retaining wall is just starting in our country.Therefore,based on the practical project of reinforced soil retaining wall of bullet train at Yichang North Station in Wuhan-Yichang section of Shanghai-Chongqing-Chengdu high-speed Railway,this thesis studies the two-stage monolithic panel wrapped reinforced soil retaining wall.PLAXIS^3D finite element software is used to analyze the force,deformation and stability of the integral panel wrapped reinforced soil retaining wall during construction,and the influence of some material parameters on the stability of the retaining wall is studied,which provides a reference for practical engineering.The main research work and achievements are as follows:（1）Combined with the research status at home and abroad,this thesis expounds the structure and construction process of the integral panel wrapped reinforced soil retaining wall,classifies and summarizes the failure mode of the integral panel reinforced soil retaining wall,and analyzes and summarizes the theoretical analysis of the stability of the single and double stage reinforced soil retaining wall.（2）According to the actual project of the integrated panel wrapped reinforced soil retaining wall of Yichang North Railway Station,PLAXIS^3D software was used to establish a three-dimensional model to study the force,deformation characteristics and stability of the retaining wall during the construction period,and the safety factor of the retaining wall was 1.94,which met the requirements of the code.During the construction period,the horizontal displacement of the wall along the wall height is"belly"type;The vertical settlement of the base of the upper and lower retaining walls is positively correlated with the height of the fill and nonlinear along the length of the reinforcement.The horizontal earth pressure of retaining wall presents an inverted"S"type nonlinear distribution along the wall height.The vertical stress of the base of the retaining wall increases with the increase of the filling height and distributes nonlinearly along the length of the reinforcement.There are two phenomena of single peak value and double peak value in geogrid tension.The shape of the fracture surface of the lower wall is similar to that of the 0.3H fracture surface,and the shape of the upper wall is similar to that of the Rankine fracture surface and the FHWA method.The position of the fracture surface moves inward to the wall compared with the three theoretical fractures.（3）On the basis of the original model,the influence of various factors on the stability of the retaining wall was studied by changing a single parameter（internal friction angle of the filler,cohesion of the filler,stiffness of the geogrid,reinforcement length,step width and post-construction time）.It is concluded that the horizontal displacement of the retaining wall and the maximum tension of the reinforcement increase with the increase of post-construction time,but decrease with the increase of other factors,and the rate of change gradually slows down.The safety factor of the retaining wall increases with the increase of the internal friction angle and cohesion of the fill,and increases first and then tends to be constant with the increase of the geogrid stiffness and the reinforcement length,while the step width and the post-construction time have little effect on the safety factor of the retaining wall.