Application Research On Thermal Insulation Materials Applied In Sulphate Salty Soil Subgrade

Xinjiang is the largest saline-alkali soil province in China, the saline soil road damage with the temperature change is an urgent problem to solve. In order to prevent the happening of the salt damage, In order to research the changes of subgrade temperature field with alterable environmental conditions, this paper is based on the long-term monitoring data of agricultural second division21-24group road section in the xinjiang, the method of finite element analysis was conducted by ABAQUS software to simulate thermal state of the roadbed with insulations in saline soil region. The main research contents and results are as follows:(1) Through the comparison and analysis, the influence of temperature field with and without EPS is studied;(2) The temperature field numerical simulation results and related data about the EPS board laying in three different embankment position are analyzed, the best position for insulation boards is presented;(3) The temperature field of roadbed about five different thickness of EPS layers is researched, the best thickness for insulation boards is presented;(4) Through the analysis of the temperature curve at the bottom of the embankment of the different embankment height with10cm EPS laying in the different position of roadbed, the relationship between the position of insulation and the height of embankment is analyzed;(5) Through the analysis of the temperature curve at the bottom of the embankment of the different embankment height with different thickness of the EPS laying at bottom of roadbed, the relationship between the thickness of insulation and the height of embankment is analyzed;(6) According to the numerical simulation results, the highest and lowest temperature on different depth of the layer are get and the salt-frost heave depth is calculated, thus further insulation effect of EPS is verified.By analyzing the calculated results, it is shown that the roadbed with EPS can effectively protect saline soil under roadbed; EPS should be placed at the bottom of subgrade; The best thickness is between5cm to10cm; The impact of EPS laying position on embankment bottom temperature is greater when subgrade is high and the impact is smaller when subgrade is low; The impact of EPS thickness on embankment bottom temperature is smaller when subgrade is high and the impact is greater when subgrade is low.