Study On The Physical And Mechanical Characteristics Of Chlorine Saline Soil And Shear Strength Parameters In Qinghai Province

China is a country with a wide distribution of saline soil, especially in the western regions such as Xinjiang, Qinghai, Gansu, Ningxia, Shaanxi and Inner Mongolia, the distribution of saline soil is the most common. In particular, highway sub-grade filler exposed in natural environment, subjected to repeated in the natural cooling and heating, sub-grade will present a salt heaving, frost heave and settlement, the intensity variation of physical and mechanical properties, serious will development for highway sub-grade disease. Highway roadbed diseases seriously affect the safety and comfort of road vehicles. Along with the rapid development of the high grade highway in the saline soil area, the physical and mechanical properties and engineering characteristics and the roadbed deformation and so on have the certain practical significance.The Charge expressway as an example, distributed widely in area of Charge Salt Lake in Qinghai Province containing salt silty clay as the experimental material, through field survey along the route and outdoor test as a means of site temperature and local temperature along the process variation, field water and salt move rules and elevating the temperature cycle of the amplitude and frequency shift of saline soil shear strength parameters. At the same time, combined with the new G215 observation of Qinghai province highway, the test section of the special treatment of saline soil sub-grade developed a detailed deformation monitoring program, a detailed analysis of the roadbed monitoring data, guidance. The main conclusions are as follows:(1) To determine the test section of saline soil in soil at different depths of soil temperature changes along the different time scales, on the whole, in under the action of high temperature and evaporation, the soil temperature and air temperature change trend of saline soil, showing a decreased with the increase of atmospheric temperature increases, but decreases with the increase of the depth of the law;(2) Determination of the test section of saline soil at different depths of the unit volume water content per unit volume and the water salt content and distribution, under natural conditions and soil thermal state change, the area test section of saline soil containing water for re migration and distribution, and lead to salt in the migration process in the surface and subsurface range formed two salt accumulation area.(3) By laboratory triaxial compression test, under the other conditions are the same, with salt content of increased first and decreased after increasing shear strength parameters(internal friction angle and cohesion), with the increase of the water content decreased, with the increase of cyclic wetting drying amplitude and frequency and attenuation, and analyzes the corresponding mechanism.(4) By the special treatment of sub-grade deformation monitoring found, in the treated by impact compaction of sub-grade layered embankment, construction progress about 4d/leavers; pleading period maintain about 2 months after the deposition rate tends to be stable; upper powder soil after construction settlement by the external environment(such as temperature and groundwater) influencing factors, put forward the feasible and effective of saline soil foundation treatment scheme.