Study on comparison and selection of construction methods for water conveyance tunnel of Beikeng Reservoir

Abstract

The water conveyance project of Beikeng Reservoir adopts pressurized gravity flow for water conveyance throughout the whole process, and the end water receiving point is the central water plant. The design diversion flow is 7.64 m³/s and the tunnel diameter is 2.4 m. The total length of the water conveyance tunnel is 8 757 m. The river terraces and eroded low mountain landforms are along the tunnel. The terrain is undulating. The buried depth of the tunnel is about 50 ~ 390 m, mainly through tuff, slate and shale. The drilling and blasting method, open TBM method and double shield TBM method are compared and selected for 1~# tunnel. From the aspects of avoiding engineering risk, reducing environmental impact and ensuring the implementation progress of the project, the drilling and blasting method is not suitable. From the perspective of controlling engineering investment, the open TBM scheme is selected.

Keywords

water conveyance tunnel / drilling and blasting method / open TBM method / double shield TBM method