Research On Temperature And Salt Migration Law Of Sulphate Salty Soil Subgrade In Xinjiang Region

With the speeding up of the construction in western China, road grade and construction standard are also correspondingly improved. Saline soil widely distributed in Xinjiang, can cause pavement salt expansion crack, aggravate frost heave and boil, erode pavement. Therefore, it necessary to research the salt migration rule of road subgrade in sulphate salty soil areas of Xinjiang, for provide the basis for road construction and disease prevention.Based on road subgrade test section of the saline soil of Xinjiang agricultural21th-22th group, the paper adopted the methods of on-site testing and finite element numerical analysis to study the temperature distribution, water and salt migration rule of sulphate salty soil. The main research contents and results are as follows:(1) Selected the field test section of the saline soil subgrade in Xinjiang, and monitored the local air temperature and subgrade temperature long-termly, then analysed the temperature monitoring data and obtained temperature distribution law of saline soil subgrade.(2) Seted the finite element model and analysed temperature distribution rule of different soil subgrade in different salt content, then combined with salt expansion sensitive temperature interval data and roughly delimited salt expansion sensitive position interval of salty soil subgrade.(3) Made the site pit samplings in natural foundation, the discard old road subgrade and geomembrane insulating layer embankment respectively, then analysed the variation rule of soil salt content with depth in different conditions.(4) Analysed the water and salt migration rule of different soil subgrade in different salt content through finite element model.(5) Researched the insulated effects of various materials insulating layer in different position through finite element numerical simulation.The paper’s studies can provide the basis for salty soil disease prevention effectively.