Experimental Study On Damage Effect Of Road Water Stabilized Layer Based On The Environmental Effect Of Saline Soil In The Frozen Area

The climate in southern Xinjiang is a typical inland extreme arid desert climate.Its climate is dry,the salinity of groundwater is high,and the temperature difference between day and night is great.The effect of strong capillary action on the accumulation of salt in the earth's soil and the drying-wetting cycles of water and salt is significant.Seasonal freezing and thawing cycles result in serious deformation and failure of roadbed structures.This special regional environmental function is mainly divided into water and salt drying-wetting cycles and water salt freezing-thawing cycles.In this paper,the experimental study on the effect of water and salt drying-wetting cycles on the saline soil environment and the effect of the deformation and damage of the water stable layer of the road structure under the action of freezing-thawing cycles in the saline soil of the southern Xinjiang frozen area is carried out.The water salt temperature environment of the roadbed structure layer in the saline soil environment of the Alar area in the alar region of Southern Xinjiang is artificially simulated.The model specimens of the subgrade structure layer are made to study the damage effect of the water and salt drying-wetting cycles,the single environmental action of the freezing-thawing cycles and the water stability of the subgrade under the action of various environmental effects.The results of the specific work are as follows:(1)Through the investigation of the early construction of the city road in Alar City in southern Xinjiang,it is found that the asphalt concrete road with cement soil stabilized base is the first asphalt concrete pavement corresponding to the shoulder part of the roadbed on both sides of the road subgrade with external water and salt infiltration.The deformation and failure of the whole pavement is caused by the interaction of salt dry and wet circulation,salt expansion and frost heave freezing and thawing in the saline soil subgrade.(2)The drying-wetting cycles of sulfate will promote the accumulation of salt in the water stable layer and erosion of the water stable layer,but it has little effect on the mechanical properties of the water stable layer;the effect of the sulfate freezing and thawing cycle on the mechanical properties of the water stable layer will decrease the durability of the water stable layer,and the water and salt dry and wet circulation will accelerate the water stability layer.(3)The vertical deformation effect of the drying-wetting and freezing-thawing cycles test of the water stabilized layer specimen shows that the driving load has a certain suppression effect on the vertical deformation of the water stable layer,but the vertical deformation of the water stable layer of the stress effective zone of the perimeter is increased.(4)The experimental results and engineering practice show that in the road engineering of the seasonal frozen soil and the saline soil area of Xinjiang,the cement soil stabilized base in the subgrade is not suitable for the special climate environment and the engineering geological environment,and it is not suitable for the new roadbed structure of the roadengineering in this area.