北坑水库输水隧洞施工方式比选研究

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

摘要

北坑水库输水工程全程采用有压重力流输水，设计引水流量7.64 m³/s,洞径2.4 m。输水隧洞全长8 750.5 m,沿线为河流阶地和剥蚀低山地貌，地形起伏大，隧洞埋深约50~390 m,主要穿越凝灰岩、板岩以及页岩。对1~#隧洞采用钻爆法、敞开式TBM法、双护盾TBM法进行比选，从规避工程风险，减小对环境影响，保障工程实施进度等方面综合考虑，不宜采用钻爆法，从控制工程投资角度考虑，选择采用敞开式TBM方案。

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.

关键词

输水隧洞 / 钻爆法 / 敞开式TBM法 / 双护盾TBM法

Key words

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