The Rule And Control Technology Of The Ground Deformation In Large Section Tunnel Which Filled By Manpower

Base on the Longdongbao airport's tunnel in Guizhou railway hub, using site monitoring,model experiment and numerical simulation method, ground movement of artificial back-filling soil and construction strategy are studied. According to the consolidation characteristic of artificial soil,soil movement of large cross-section tunnel is studied. The strategy of construction is given on the basis of ground and subsurface movement. Following results are obtained:1. According to theoretical analysis and indoor experiment, consolidation characteristic of new artificial back-filling soil is carried out. Base on the consolidation property, consolidation amount of the soil is predicted.2. Using site monitoring, model experiment and numerical simulation method, relation between settlement on the arch and ground settlement is studied. We find out that the main reason of the settlement refers to soil consolidation.3. Based on the Longdongbao tunnel project, using the bench method with core soil saving and arch-shape crown foot pilot, single strengthen technique of ground movement control for tunneling in the new artificial back-filling soil is studied. The effect of such construction strategy is also given. First, advance support should be installed to ensure stability of rock mass; Strengthening job should be done simultaneously around the full circle of the tunnel;Then the secondary lining should be installed as soon as possible.The study results directly help the construction of Longdongbao tunnel in the new artificial soil and it also help us gain the experience of tunneling in the soft soil.