Impact of Evaluation of Freeze–Thaw Cycles on Collapse Zone at Entrance and Exit of Loess Tunnel

The entrance and exit of loess tunnel are easily affected by freezing thawing, which leads to collapse in cold regions. Based on the slip line network method, this paper proposed a graphical method analyzed impact evaluation freeze–thaw cycles zone at tunnel. Firstly, was improved for calculation program, program validated monitoring data evolution an unlined situ. Then, some triaxial tests were carried out loess, attenuation law strength summarized after Finally, applied evaluate range results show that introducing classic field into analysis process can provide feasible efficient surrounding rock arch engineering, increases with growing number cycles. Moreover, suffered from would cause area increase maximum 16.13%.