Study on the Construction Time of Secondary Lining in Loess Tunnel

The construction time of secondary lining in loess tunnel has been the focus of attention in the tunnel field, but no specific quantitative discriminant index of the construction time of the secondary lining has been applied. Relying on the Wofosi tunnel of Zhangjiakou-Zhuolu highway, based on the deformation characteristics and deformation rate analysis of the crown settlement and surrounding convergence, proposed that the stability of basic rate as the indicators of construction time of secondary lining, determined preliminarily the construction time of secondary lining by optimizing the regression model, combined with the characteristics of the rock pressure and pressure distribution state along the hole to determine the best construction time of secondary lining