| The current design concept of roadbed in our country is mostly based on the statics theory,but the vehicle load is a kind of dynamic load,and the effect of replacing the vehicle load with static force on the roadbed is obviously insufficient.With the successful conclusion of China’s 13 th Five-Year Plan,China’s transportation industry has been vigorously developed,Highway transportation is characterized by "large flow","high speed","not light that is heavy",etc.Subgrade is affected more and more by automobile load,it is necessary to consider more dynamic method in subgrade design theory.In this paper,the field experiment of dynamic response of subgrade was carried out by the invention patent of the research group,and the dynamic effect of vehicle load on subgrade was calculated by numerical simulation software FLAC 3D.The main contents are as follows:1.Based on the characteristics of the traffic load,the change mechanism and law of the traffic load are analyzed,and the application status of the commonly used simplified vehicle load model is described.Two kinds of additional dynamic stress modes and response mechanism under vehicle load were analyzed from the perspective of dynamics,which provided early theoretical preparation for the subsequent field experiments and numerical simulation.2.According to the patent description of the research group and combined with the field conditions of the test,the device used to observe the real-time deformation of embankment filling of each layer under the action of vehicle load is made,and the dynamic and deformation response under the action of vehicle load is described with the earth pressure sensor.At the same time,more applications of the device are studied theoretically and practically.3.According to the field conditions,the road model and the test site model were established by using the numerical simulation software FLAC3 D.By comparing the measured data with the simulation results,the feasibility of the simulation software and method was determined,which provided a guarantee for the subsequent extensibility calculation.4.The dynamic response range of the subgrade on cross-section is analyzed by the model of the test section,and the dynamic response law of the subgrade at different depths under the action of different speed and axle load is studied.At last,the cumulative plastic deformation of subgrade under standard and overload conditions is analyzed by simulating cyclic loading conditions. |
