Study On Mechanical Response Of Highway Retaining Wall Under Vehicle Dynamic Load

In recent years,traffic construction projects in mountainous areas such as northwest and southwest of China are becoming more frequent.Retaining wall structure is the most commonly used engineering protection method to stabilize highway roadbed slope.Vehicle loads acting on highway pavement are composed of vehicle dead weight and vibration loads generated during vehicle driving.At present,the design method of highway retaining wall is to simplify vehicle loads to static loads,which completely ignores the influence of vehicle dynamic loads.Different from before,the rapid development of the automobile industry makes the speed of vehicles faster and faster,and the number of heavy vehicles is also increasing.Whether the dynamic load of vehicles has an impact on the retaining structure of retaining wall has not yet been clearly concluded.Therefore,relying on practical engineering cases,this paper studies the response law of highway retaining wall under vehicle dynamic load.The main work is as follows:(1)Summarized the theory of retaining wall,vehicle load and numerical simulation,analyzed the characteristics and applicability of commonly used vehicle load model,and analyzed the Similarities and differences of two vehicle load conversion methods in the code.(2)The two-degree-of-freedom vibration model of a quarter body structure is used to solve the expression formula of vehicle vibration effect.The analysis shows that the vehicle dynamic load is directly related to road roughness and vehicle speed.In this paper,the halfwave sinusoidal vehicle load model is selected as the dynamic load loading mode and the conventional equivalent conversion method of vehicle load is improved.(3)Combining with an engineering example,a three-dimensional model is built by FLAC3 D finite difference software to load vehicle loads.The response law of highway retaining wall structure under no-vehicle loads,vehicle static loads and vehicle dynamic loads is analyzed in detail.It is considered that the vehicle dynamic loads have some influence on the retaining wall structure.(4)According to the engineering example,the equivalent replacement of vehicle load is calculated by using the method of vehicle load conversion in the code and the improved method,and the stability of retaining wall is analyzed by using the software of marble rock and soil combined with the calculation parameters.It is concluded that the improved method is more accurate in evaluating the stability of retaining wall.