The Renovation Of Railway Roadbed Disease On Yangan

The expansion soil on YangAn railway roadbed cause many diseaseses, such as mud pumping, ballast pocket and settlement and extrusion, etc. when being serious there are too mud on sleeper and roadbed to walk on it, it is hard to keep the size of geometry of the track and often cause the car shaking and influence the security of the driving seriously. Sometime it had to set up disease sign to restrict the vehicle velocity.Through investigation and analysis, this thesis put forward that the roadbed disease are caused by the surface water' s softening of the base soil with bad nature. With the raise of the water containing rate, the shear strength drop, and easy cause ballast pocket. Ballast run into the roadbed' s top layer, conduce soil liquefaction under the repeated train loading. When the train pass, because of the rise and reduction of the pressure by function of sucking and releasing the hole water pressure of nearby the top layer increases, mud rises from the interstice of the roadbed and rise to the surface of roadbed.This thesis consider that dealing with the roadbed disease should be the improvement in expansionsoil property on one hand, should be isolated the surface water to influence the roadbed on the other hand; Strengthen maintenance work; keep the railway line' s good state, reduce the stress of the roadbed.There are varied method to deal with the mud pumping problem, I think isolate surface water using plastic board is the most effective method at present. ( use geotechnical cloth in tunnels, playing the role in filtering the groundwater), using lime and mixed soil to improvethe nature soil property, And using the geotechnical form to improve the strength of the roadbed.We put forward the rational renovation according to the reason of the disease characteristic and has renovated the inflation roadbed disease section of the YangAn railway line. The renovate result is obvious. Result indicate that the renovate and measure scheme is correct, the work have sure guidance functions to renovate other railway line disease.