Research On The Mechanical Properties And Structure Optimization Of Cantilever Retaining Wall

Cantilever retaining wall is a light retaining structure which has the characters of convenient construction process, significant economic benefit, better structure, etc, so it is widely used in the field of railway, highway, water conservancy, etc. By controlling the geometry size of the retaining wall, the settlement and deformation of the embankment filling behind the cantilever retaining wall can be decreased, so based on the existing structure of the cantilever retaining wall, when the embankment becomes a little high, the thickness of the vertical panel will be larger and the length of heel slab will be longer as respond, then the engineering cost is significantly promoted. During the process of subgrade construction of high-speed railway, there are always occurring situation of high embankment, the TB10025-2006 The railway subgrade retaining structure design specification of our country regulates that the height of cantilever retaining wall is better below 6 metre, because of the limitation to the wall height, cantilever retaining wall is harder to adapt to the requirements of the development of the high speed railway subgrade. Compared with other type of retaining wall, cantilever retaining wall has the character of convenient construction process, for improving application prospect of cantilever retaining wall in the situation of high embankment, it’s necessary to search on the interaction mechanism between cantilever retaining wall and the filling behind the wall, then creating a novel cantilever retaining wall which can adjust to condition of high embankment.Based on numerical analysis of ABAQUS and combined the results of field measurement, this paper makes mechanical analysis for Reinforced cantilever retaining wall, which optimizes research work from two aspects-embedding bar strip into filling behind the wall and setting buffer layer at the wall back of the retaining wall, then propose a novel cantilever retaining wall. The main content and work just as follows:(1) Build the 2 d numerical model by simplify the prototype site of cantilever retaining wall, then with considering the characteristic of interaction mechanical functions between retaining wall and soil body, analysis the influence of attributes of filling materials which is filling modulus, internal friction angle and cohesion to distribution law and values of the earth pressure and displacement of wall in turn, beside comparing with classical earth pressure theory. The results suggest that the distribution law of earth pressure of reinforced cantilever retaining wall is consistent with that of classical earth pressure theory, that is to say the distribution of earth pressure is triangular shape which enlarge from the top of the wall to the bottom, the maximum earth pressure is at intersection of the vertical arm and bottom plate. At current condition of the filler, there is no plastic area in the filling and the whole structure is in the state of elasticity, the earth pressure is stable and won’t be smaller as the strength enlarge, improve the strength of the filling behind the wall has no big influence on decreasing the earth pressure.(2)Embed the bar strip into the filling behind the wall to investigate the optimization effect and discuss the type of bar strip material, distance and response of length parameter. Choosing zinc-plating steel strip, reinforced concrete strip and rigid plastic composite goblets as bar strip materials, the distance choose 0.3m,0.6m,0.9m, the length of the bar strip is choosing 1 time of the length of the heel plate(5.5m),1.5 times of that(8.25m),2 times of that (11m). There are necessary to figure out that by embedding bar strip into filling to comprise the structure, the way go against the displacement relieving of the reinforced cantilever retaining wall and the bar strip can’t give full play to it is tensile resistance, so it has no significant attribute to reduce earth pressure.(3)In the way that set buffer layer between the retaining wall and filling as well as reinforce the filling to make the wall occur larger lateral displacement and reduce the restriction effect of retaining wall on the filling, then the bar strip in the filling can act well. This paper discusses relationship between the thickness of the buffer layer modules of that and distribution and values of the earth pressure and displacement of wall respectively.The results suggest that on the premise of no yield zone in the structure, the resultant force of earth pressure and maximum earth pressure is decreasing when enlarge the displacement of the wall, modules of buffer layer have greater influence on the earth pressure as the thickness of the buffer layer increase.(4)Based on the research above,proposal a novel structure of retaining wall that setting buffer layer between the wall and filling.Choosing earth pressure under the working condition that the thickness of buffer layer is 0.5m and the module is 1.7MPa as design load to design the structure of retaining wall.The results suggest that the thickness of the panel of retaining wall can reduce from 1.7m to 1m which decrease about 41% compared former, it reduces the brickwork quantity and construction effectively. This novel structure improve the application prospect of cantilever retaining wall and has a certain reference value.