Experimental Analysis And Research On The Prevention And Treatment Of Saline Soil Diseases By Changing The Structure Of Saline Soil Roadbed

This article relys on the alar in the southern of xinjiang. The research mainly about changing the structure of saline soil roadbed to find the method about combating the disease which is cased by saline soil such as salt expansion and collapsibility and so on.The new structure of saline soil roadbed is named "obstruct the beyond and dredge the download".we did some experiments such as thermal conductivity, permeability coefficient and frost heave and so on at the beginning of the research.And then we did experiments with the small model of roadbed to find the most favorable form of the hydrophobic layer.By the test of the big model of roadbed,we studied on the effect of new structure of saline soil roadbed on the disease which is cased by saline soil. The results show that:(1) The formation of the permafrost layer in roadbed has great influence on the distribution of soil moisture,and affects the distribution of Soil salinity.(2) The thermal conductivity of the saline showes a parabolic relationship with the soil’s salt content. The thermal conductivity of the saline soil increases with increasing salt content, when it reaches a certain level, thermal conductivity is reduced with the increase in the amount of salt in the soil. Thermal conductivity is increasing with the increase of the moisture content. The thermal conductivity of the saline soil increases with increasing density.(3)With the influence of temperature,there are not only frost heave but also expansion deformation will occur. Salt expansion will leave the amount of deformation residual after ablation, the residual amount of deformation will gradually increase when the freeze-thaw alternately ongoing.(4) When the slope of the hydrophobic layer in the roadbed is set to the v-shaped:, the effect of slope of15°on the salt discharge is the best, followed by the slope of10°. When the slope of the hydrophobic layer in the roadbed is set to the inverted v-shaped:the effect of slope of15°on the salt discharge is the best, followed by the slope of20°. Compare the effect of the two subgrade model on the salt discharge, the v-shaped is better than the inverted v-shaped.(5) Different depths of the embankment structure mode have the salt expansion in the cooling process, However, the deformation is mainly concentrated in the surface. The new roadbed structure deformation amount are less than the the the traditional roadbed structure model,it shows that the new roadbed structure can reduce the dangers of saline soil.(6) By analyze the causes of traditional saline soil road damage in Alar and comprehensive results of laboratory experiments roadbed model. Set the hydrophobic layer in the roadbed. So can subgrade moisture affected by rising groundwater levels of emissions,at the same time,it could discharge the water which penetrate in the road through the green belt and the surface of the the road.In order to reduce frost heave that caused by the water which can not be discharged within the roadbed. Use hpds-2006software for road pavement design, to improve The traditional saline soil subgrade.Through the improve to ensure that the roadbed in the dry or wet state,so can reduce the damage which is caused by Saline soil..