Study On Subgrade Stability Evaluation Method In Wudaoliang Permafrost Region Of Qinghai-Tibet Railway

The special permafrost environmental characteristics and climate warming tendency in future decided the cooling subgrade idea should be adopted during Qinghai-Tibet railway subgrade design. Many comprehensive measures of degrading the ground temperature at bottom of embankment should be used to protect permafrost under subgrade. As many unsure factors relating to climate warming and permafrost environment changing could affect the long-term stability of subgrade greatly. How to evaluate the subgrade stability after the railway being in use was the most important item for Qinghai-Tibet maintenance.By means of ground temperature data from different types of permafrost structure section in low temperature area, wudaoliang, the long term stability evaluation method was studied for different style of subgrade structure. The paper include,To carry out the study on stability evaluation for permafrost subgrade, the ground temperature monitoring system was build in wudaoliang area of the low temperature permafrost region.The ground temperature data variation with time and depth from subgrade, bridge and culvert basement experiment were arranged and analyzed depending on the different section of the long term monitoring in Wudaoliang permafrost area.The paper studied the main effect and control factors of permafrost subgrade stability. Considering these factors, the theoretical fuzzy comprehensive modal was built. With this method, the different area of permafrost subgrade stability was evaluated for Qinghai-Tibet railway. Furthermore, the fuzzy inference rule modal was established to evaluate the test sections stability in Wudaoliang area.According to artificial neutral network, the ground temperature and settlement mapping relation modal were deduced to evaluate the permafrost subgrade stability of embankment with riprap in high temperature and fine soil area of Qinghai-Tibet railway.In general, in response to the permafrost engineering practice, the paper studied the effect factors for subgrade stability in Wudaoliang area of Qinghai-Tibet railway. Based on fuzzy mathematics, artificial neural network evaluation built-up modal, the corresponding stability evaluation methods for Qinghai-Tibet permafrost subgrade were presented. The results would affect directly for subgrade disease control and the railway prewarning, furthermore, it would guide the similar engineering construction well for future.