Open AccessDiscussion on The Design of Water Blocking and Drainage Limit of Water-rich Mountain Tunnel in Ecologically Fragile Area
Author(s) -
Zhien Zhang,
Mingli Huang,
Jiefang Huang
Publication year - 2020
Publication title -
iop conference series. earth and environmental science
Language(s) - English
Resource type - Journals
eISSN - 1755-1307
pISSN - 1755-1315
DOI - 10.1088/1755-1315/510/5/052059
Subject(s) - shotcrete , drainage , groundwater , environmental science , block (permutation group theory) , geotechnical engineering , vegetation (pathology) , geology , hydrology (agriculture) , ecology , medicine , geometry , mathematics , pathology , biology
In mountainous areas with abundant groundwater and high water pressure, the design of waterproof and drainage is the most important part of the whole tunnel construction process. Improper treatment of groundwater will not only damage the local ecological environment, but also bring hidden danger to the safety of tunnel structure, especially in the ecologically fragile area. The tunnel project under construction in the East Tianshan Mountain is located in the high-altitude mountain area. The surface is the national forest protection area, and the vegetation is perennial. Once a large amount of groundwater is lost, the surface ecology will be damaged and hard to recover in a short time. In this paper, the existing design of mountain tunnel waterproof and drainage is summarized, and its advantages and disadvantages are analyzed. Based on the previous research, the concept of waterproof and drainage design suitable for the East Tianshan tunnel is proposed: “one block, two rows and Three Preventions”. “One block” is a circle of grouting outside the tunnel to block most of the groundwater. “Two rows” is to set two layers of drainage pipe network between shotcrete and waterproof layer and between waterproof layer and lining. “Three proofing” is to use three layers of water proofing: shotcrete layer, special waterproof layer and lining concrete. Layers of fortification can minimize the interference to groundwater and ensure the safety of tunnel structure.