Research On The Interaction Mechanism Of Unsymmetrical Subgrade And Pier Along The River And The Protection Technology Of Pier

Along the road along the river has characteristics of the building,due to the influence of topography,the road is based "non symmetry",in the construction of subgrade,sometimes will be buried in the roadbed pier situation,if the blind construction of subgrade construction,will give the bridge safety brought hidden trouble.Asymmetric filling roadbed,breaking the balance of the original pier mechanical conditions,compared with symmetric subgrade,bridge pier not only bear the filling soil pressure generated and negative friction,but also has certain anti sliding ability under subgrade instability effects decline under stress,coupled with a variety of factors,soil-pier interaction mechanism and characteristics of extremely complex.This paper firstly summarized and summed up the status quo of research at home and abroad,and then expounds the asymmetric subgrade soil-pier interaction mechanism,and then using the Midas finite element analysis software GTS on Subgrade backfill effect on single and double pier structure,and puts forward the corresponding pier protection scheme,the specific contents are as follows:(1)Through the establishment of three dimensional finite element model of soil-pier,analyzed the soil for single and double pier settlement,horizontal displacement,and comparing the calculation results with the relevant norms,proposed single and double pier structure of critical filling height of roadbed and double pier structure of critical pier spacing.(2)Use of finite element model,analyzes the influencing factors to horizontal displacement of single pier structure filling,such as bulk density,elastic modulus,Poisson ratio,internal friction angle and cohesion,analyse the influence of various factors on the pier,backfill materials provide a reference for practical engineering selection.(3)Through the establishment of soil-casing finite element three-dimensional model of steel tube,reinforced concrete casing in the filling height of the displacement and stress of Von Mises,support for the two kinds of comparison analysis,comparing the calculation results with the relevant norms,put forward two kinds of in the tube filling height minimum wall thickness and Minimum net distance of pier-casing.(4)Combined with engineering practice,a finite element model of direct backfill and protection against backfill is established.The results of this study are applied toactual projects,and numerical simulation and comparative analysis are carried out to verify the reliability of the research results.