Optimization Design Of New Guardrail Structure In The Transition Section Of Road And Bridge Based On Collision Simulation

In the design of transition sections of highway guardrails in China,there are often significant safety hazards in the structure of transition sections between A-grade corrugated beam guardrails for roadbeds and SB grade concrete guardrails for bridges.Many accident cases have shown that when vehicles collide directly with the transition section of the guardrail,due to the different stiffness and strength of the corrugated beam guardrail and the concrete guardrail,the collision vehicles may experience obstacles,overturning,and other phenomena,which can cause great harm to passengers.Therefore,the thesis conducts research on the transition section structure of the A-level corrugated beam guardrail on the roadbed and the SB level concrete guardrail on the bridge.The main research work is as follows:(1)Analyzed the deficiencies in the protective capacity of traditional road bridge transition guardrails.The computer simulation method was used to study the traditional road bridge transition section guardrail,and its protective ability was analyzed from four aspects: blocking performance,buffering performance,guiding performance,and deformation situation.It was found that the maximum acceleration of the vehicle center of mass after collision exceeded the standard limit of 200 m/s2,posing a threat to the safety of passengers.The protective capacity of traditional guardrails in the transition section of roads and bridges is insufficient,and it is necessary to design new guardrails to replace traditional guardrail structures in the transition section of roads and bridges.(2)On the basis of traditional road bridge transition guardrails,a design scheme for a new type of guardrail in the road bridge transition section is proposed.Two improvement schemes are proposed for traditional road bridge transition guardrails,namely,improved N-shape columns and the imitation bamboo shape columns.Through collision simulation analysis,it was found that the safety performance of the improved N-shape column scheme is better than that of the imitation bamboo column scheme,Therefore the new guardrail structure of the road bridge transition section in this article adopts an improved N-shape column.A comparative analysis was conducted with the guardrails in the road bridge transition section optimized by traditional methods,Found to have good safety performance and more economical and feasible.(3)The new guardrail structure of the transition section of road and bridge is optimized for design.Conduct full factor tests on the new guardrail in the road bridge transition section and select the best scheme based on entropy weight method and TOPSIS method.According to collision simulation and cost accounting,it is found that the optimized new guardrail in the road bridge transition section has excellent safety performance,meets national standards,and is cost-effective.This indicates that the optimized new type of guardrail in the transition section of roads and bridges has good application prospects in practical engineering.