Mechanical Characteristics of an Open-Buried Double-Arch Tunnel during Construction

The open excavation and concealed construction method is widely adopted for the of bias double-arch tunnels. However, mechanical behavior tunnel during whole period by using not well understood, basis organization optimization lacking. Based on an open-buried Xiajuan Road, Changsha City, China, on-site monitoring was carried out in terms deformation steel arch primary lining, stress reinforcement secondary surrounding rock process. correlation between vault settlement rate strain analyzed. results show that maximum settling left right caverns occur at different locations due to supporting conditions. peripheral displacement experiences a process convergence inward extension outward. compressive lining cavern greater than cavern, except points waist. backfill above reduces loading but it increases cavern. effect controlled balanced when adopted.