Research On Mechanical Properties Of Cold Resistance Layer Of Subgrade In Seasonal Frozen Area

Seasonal frozen soil are widely distributed in our country, accounting for about53.5%ofthe land area in china. Seasonal frozen soil area road disease such as frost heaving, frostboiling, net cracks, uneven settlement influence road and the road performance and servicelife. Now common governance measures for filling roadbed, heightening embankment, thelaying of geotechnical materials, but are unable to fundamentally solve season permafrostsubgrade freezing and thawing phenomenon.Seasonal frozen area road diseases is mainly due to the moisture in winter to freeze themigration area caused by freezing swelling caused by road bulging, cracking etc., springthaw freezing melting zone of the water cannot be discharged in time, in under the trafficload caused by boiling. This paper put forward the XPS board and rubber particlesmodified fly ash composition of cold resistance layer as roadbed filler. Subgrade with coldresistance layer through of roadbed thermal insulation and blocking in subgrade moisturemigration channel two aspects to governance in seasonal frost area road diseases. Butbecause of the cold resistance layer in XPS plate strength relative to other small roadstructure layer. Therefore, according to the mechanical properties of cold resistance layerof subgrade is studied.1. Considered to have greater relationship to XPS board mechanical properties and densityfirstly measured with XPS board density, elastic modulus, pressure distortion mechanicalproperties. Fly ash modified with rubber particles was determined by three tests of internalfriction and cohesion. Through the shear test determination of bond strength between XPSslab and base, rubber particles modified fly ash soil.2Though outdoor cold resistance layer of subgrade simulation test. The results show thatby XPS plate and rubber particles modified fly ash group layer of cold resistance layer as aseasonal frozen area of soil subgrade filling a good cold resistance, heat preservation effect.And for the suppression of road frost heave and winter due to frost heave additional stress has a positive effect.3Through the finite element analysis of the subgrade under cold resistance, themechanical properties of the road structure are calculated.. Stress analysis of the verticalstress, vertical deformation of the road under the load, and the shear stress of the structureof the road under the unfavorable driving conditions. The results show that the verticaldisplacement of the road structure is small, and is continuous, without mutation..According to the adverse driving conditions, the top and bottom shear stress of the XPSplate are calculated, and the shear strength of the road structure is proved to be enough,and the structure layer cannot be destroyed.