Study On Dynamic And Its Parameters Of Heavy Shaul Railway Subgrade

The progress of the overloaded transportation technology trends, from the world as far as possible increase the axle load, make full use of existing station line length, has gradually become the mainstream direction of overload transportation, large axle load truck has a broad development prospects. But as overloaded railway axle load unit or the development of the block train, than in the general line, overloaded railway subgrade related design for aspects put forward higher requirements, and clear overloading railway roadbed in the dynamic response under dynamic load disturbance is the precondition of subgrade design, thus to study the dynamic response problem of overloaded railway subgrade, and then explore the optimization of subgrade parameters has important practical significance.In this paper, in order to better analyze overloaded railway dynamic load of roadbed disease induced effects, further optimization of overloaded railway subgrade parameters design, mainly done the following work:(1) first of all, through the understanding of overloaded railway development situation at home and abroad, to realize overloaded railway development in our country and foreign gap, overloaded railway development in China started late but fast development, the axle load unit of overloaded railway in the broad prospects for the development in our country;(2) the second, by comparing the simulation analysis, field measurement and expression of train load processing methods, from the Angle of dynamics research applicability, established the expression analog excitation load as the train load simulation;(3) on the basis of predecessors’ research results, this paper adopts the method of combining theoretical analysis and numerical analysis study of dynamic response problem of overloaded railway roadbed, the rail as a supporting beam in a row, using theoretical analysis method for sleeper fastener points of reaction solution, coupled with ABAQUS sleeper- multilayered subgrade system numerical model is established to study the dynamic response of roadbed, and according to the results of numerical analysis on the effectiveness of the proposed model is verified;(4) the deformation of roadbed is an important index of assessment of embankment quality, its acceleration can better characterization of subgrade intensity by dynamic disturbance, therefore based on the dynamics calculation results in this paper, the output of overloaded railway subgrade under dynamic load disturbance dynamic displacement and acceleration time history curve of the case for the careful analysis, and the axle load of 25t~35t subgrade under dynamic displacement and acceleration has carried on the comparative analysis, demonstrates the overloading the especially big axle load unit heavy-load railway roadbed, the necessity of optimizing design;(5) thickness and elastic modulus of solid bed, bed surface layer thickness and elasticmodulus of subgrade dynamic displacement and acceleration under 35 t axle load for analysis, the influence of optimum design of large axle load of freight line subgrade provide certain reference value.