Numerical Analysis Of Mudstone Cutting Deformation In The High Speed Railway Under Weak Expansion And Train Loads

With the rapid development of high-speed railway,many remarkable achievements had made by Chinese high-speed railway,gradually became famous in the world.High-speed railway was popular to the public for its unique high speed,high comfort,high security,and was famous to engineers for its unique high request,high standard and high quality.While high-speed railway brought convenient,but also brought trials and challenges.Due to the vast territory,complicated geological conditions,geographical distribution of complex,a so-called " engineering problems soil" of expansive soil wide distribution in our country,this passage based actual engineering of expansive mudstone cutting,which in the operation of high-speed rail the large deformation of rail end face,the serious influence line of comfort and security,high speed running.How to solve the influence of expansive soil for high speed railway and the dynamic response analysis of train load,is the moment problem to solve.In this paper,expansive mudstone cutting deformation of high-speed railway and the dynamic response under the train load of the second-line Hami was studied,and compared analyses the numerical simulation without consider expansion,and when considering expansion with different methods introduction of expansive force were carried out.The main work and achievements of this paper as follows:1.This passage through indoor experiment preliminarily determine the expansive mudstone is hard,low moisture content,the expansion of the liquid plastic limit is larger,and weak to moderate swelling expansion sandy mudstone.In the same initial dry density,the greater initial moisture content,the smaller expansive force of remolded sample;While the initial moisture content the same,the greater the initial dry density,the larger expansion of the remolded sample.And expansive force test results of the remolded sample was compared with the results of the expansion of the undisturbed soil strength test,in the same test condition of the expansion of the undisturbed mudstone is greater than the results of remolded mudstone,and the overlying load has significant inhibitory effect to the expansion of the expansive mudstone deformation.2.The characteristic parameters was confirmed by trial model numerical calculation model of cutting ring,and then the parameter applied into the expansive mudstone cutting model,under the 3 condition without expansion force,with expansion force in the form of a uniformly distributed load and temperature expansion in temperature field to replace the humidity expansion in the humidity field,the expansion of the mudstone high-speed railway roadbed deformation simulation calculation was taken on,and get the results when in the condition without considering the expansive force under the action of the unloading effect of mudstone cutting can be made cutting certain deformation and stress changes;In a uniformly distributed load is introduced into expansion force,the vertical displacement of rail roughly symmetrical from left to right,the overall displacement around the extremer in the top of the cut slope.The maximize vertical displacement of the two extreme points,one is at the bottom of the cutting board on the scope of the vertical up deformation;another biggest vertical displacement downward on both sides of the upper part of slope body in cutting.In the direction perpendicular to the railway,the maximum deformation is located in the foot of slope and symmetrical shape.In the direction of along the line,the deformation of almost zero;Temperature expansion in the temperature field to replace the humidifying expands in the humidity field,the simulation results and with uniformly distributed load into the expansive force roughly the same only a small difference in value.3.And under the train load,regardless the expansive force under the action of the mudstone deformation of roadbed did not influenced by train loads;While the uniformly distributed load is introduced expansion force,the top surface of rail the vertical up displacement decreased in a certain degree;In the expansion of the temperature field replace the humidity field,under condition of train load compared with expansion force introduced by uniformly distributed load result,only slightly smaller in value.The expansive mudstone under train load cutting deformation compared with the does not consider the train loads of contrast,obliviously train loads influence scope is limited,but for orbital smoothness greatly influenced the orbits of the plate at the bottom of the dynamic response is more obvious,and considering the expansive force under the condition of the big vertical up displacement also within the scope of the humidifying expansion after considering the high-speed train load,caused by the expansion deformation of expansive force will appear a certain compression.4.When the field monitoring data compared with the results of numerical simulation study,shows the results of cutting expansion deformation of the roof of rails to the vertical deformation from 14 mm to 15.5 mm,with the top surface of the medial two rail deformation value simulation results is 14.0 mm and 14.8 mm,outside two rail is 14.8 mm and 15.5 mm,and the filed measured data shows that rail top surface vertical deformation of the cutting range is stability in 14 mm,means under the condition of field expansion conditions continue to deteriorate,the expansion of the mudstone cutting is having some shallow potential.