Study on Optimizing Installation Technology of Movable Steel Guardrails in Reconstruction and Expansion Projects of Expressways

In order to improve the protective performance of the temporary movable steel guardrail used in the reconstruction and expansion of expressway, according to the application scenario of the movable steel guardrail, the maximum lateral displacement in the process of vehicle collision guardrail was taken as one of the constraints of the model, and the anchorage distance and steel plate thickness of the guardrail were established as the design variables. A multi-objective optimization model was proposed to minimize the vehicle centroid acceleration and maximize the distance between the vehicle and the right edge of the steering exit frame. According to the actual vehicle crash test, the automobile finite model and the movable steel guardrail finite element model are designed to meet the current safety performance evaluation standards and collision accuracy. Furthermore, a simulation test of vehicle collision with guardrail was designed including 25 test sample points, and the simulation results were fitted with the constructed RBF model. Based on the fitting results, the optimized model was solved by the designed genetic algorithm, and the Pareto solution set was obtained. The optimization results show that with the lateral displacement is less than 2m, the acceleration of the vehicle's center of mass is reduced and the distance between the vehicle and the right-side line of the guide exit frame is increased by reducing the anchorage spacing and increasing the steel plate thickness of the guardrail, which improves the protective effect of the guardrail and provides a certain reference for engineering application.