Analysis And Research Of Back Pre-roof Of Reinforced Concrete Arch Bridge Abutment Based On Composite Anti-thrust System

The excessive horizontal displacement of the abutment is one of the most important causes of the failure of the thrust arch bridge.The horizontal displacement of the abutment can be reduced by the anti-pushing of the arch bridge.For the construction of the thrust arch bridge on the soft soil foundation,the post-combination anti-push The selection of the system is a very important content.In this paper,a combined anti-pushing system using the anti-skid plate + group pile +post-top pre-top technology is proposed for this problem.By using the jack to pre-top the two ends of the abutment and the rear anti-skid plate in the construction stage,the abutment is generated in advance.The horizontal displacement in the middle direction compensates for the horizontal displacement of the abutment under the post-load,improves the safety reserve of the arch bridge,and prevents the maintenance and reinforcement of the bridge due to excessive displacement of the abutment.The characteristics of the anti-pushing system of the post-stage pre-top combination are as follows: Firstly,the pre-biasing of the arch pile group foundation to the river center is pre-biased by the pre-top,thereby improving the stress of the main arch ring structure and increasing the horizontal thrust resistance of the group pile foundation;It is to make the anti-skid structure of the anti-skid plate pre-displacement to the stage,thereby enhancing the anti-pushing ability of the anti-skid plate,and changing the active earth pressure of the post-station body to the passive earth pressure.This technology is mainly for the applicability of arch bridges with thrust on weak foundations.In this paper,the corresponding mechanics and finite element analysis theory is proposed for the combined anti-pushing system of the post-stage pre-top,and the application research is carried out in the background of a three-span continuous arch bridge built on the soft soil foundation.Firstly,the mechanical analysis model is established for calculation,the pre-push force is calculated according to the calculation data,and the structure check is performed to meet the structural safetyrequirements.Then the finite element model is built for simulation calculation.Finally,the mechanical analysis model and the finite element model are used to simulate and compare the three schemes of pre-topping technology and resisting skateboard without pre-topping and non-resisting skateboarding.The calculation and analysis of the internal force and displacement values of the pre-topping stage and the key sections after bridge forming are carried out.,study the pre-top effect and draw the corresponding conclusions.The research results of the thesis have important reference value for the design,construction and research of thrust arch bridges in the future.