Optimization of Construction Scheme for Loess Tunnel with Super Section

Through the research of the Fu Jiayao 1^# tunnel for Zhonghe to Shuifu section of the Lanzhou-Qinwangchuan Expressway,the optimization of construction scheme for loess tunnel with super section was proposed from the aspects of technical economy,monitoring measurement,numerical simulation,etc.Mathematical analysis was proceeded based on the data from on-site monitoring measurement of tunnel vault subsidence and peripheral displacement convergence.The force and deformation of the tunnel surrounding rock and the support in the excavation process was summarized.Meanwhile,the threedimensional model of tunnel excavation process was simulated by using finite element software MIDAS/GTS.Comparing the calculated data with the on-site monitoring data,the tunnel is demonstrated to be stability,which shows that the construction schemeis optimized and reasonable.This method is of reference significance for the construction of the same type tunnels currently.