Study on the construction deformation of a slotted shield in loess tunnels with different buried depths and large sections

Since there is no precedent for the use of slotted shield tunneling in large section high-speed railways China, relevant technological accumulation and systematic research achievements are few. Therefore, this paper provides theoretical support loess tunnel construction decision-making through study shields expected to promote mechanization even intelligent a iron-loess tunnel. Taking Luochuan Xiyan railway as engineering background, uses numerical simulation software packages ANSYS FLAC3D deformation (surface settlement, vault bottom uplift, horizontal convergence) caused by three different buried depths 30, 40, 50 m surrounding rock. The law mechanical characteristics cutter cross-section tunnels under influence put forward. Results showed that 1) mutual interference between working procedures can be significantly reduced inserting cutting tool into soil instead advanced tubule before excavation; 2) settlement upper part longitudinal axis largest; greater depth is, smaller surface is; 3) arch waist foot symmetrically distributed during whole process tunneling.