Key Techniques for the Design of the Gaoersi Extra-Long Single-Tube Tunnel on the Sichuan-Tibet Highway
1 Sichuan Provincial Transportation Department Highway Planning, Survey, Design and Research Institute
2 Sichuan Province Transportation Department Highway Administration
Abstract：
The Gaoersi Tunnel, which is a bi-directional single-tube extra-long mountain tunnel at high altitude, is one key project of the reconstruction of the No. 318 National highway. At present, relative design standards for refuge devices in highway tunnels are absent, and only some requirements exist for waterproofing and drainage regarding freeze-proofing and swell-proofing in frigid areas. There are also no countermeasures concerning lining heat preservation or guidelines for design, construction, and organization in alpine regions. This paper demonstrates the technical standards, horizontal and vertical line levels, and type of pavement structures for a bi-direction single-tube tunnel in high altitude taking into account the features of seasonal freezing and thawing. Aadditionally, it analyzes the necessity of providing emergency exits. Furthermore, the parallel pilot was excavated for vehicles, and the segments in the vertical direction characterized by pressed-in ventilation of the parallel adit and a cross-passage connection were optimized. Such measures as deeply embedded central draining pipes under the invert and thermal insulating layers outside of the lining were established. The definition of and requirements for construction in winter are introduced and the scheme of oxygen supply during construction in plateaus is formulated.
TANG Xie-1,
Li-Hai-Qing- 2,
LIN Guo-Jin-1 etc
.Key Techniques for the Design of the Gaoersi Extra-Long Single-Tube Tunnel on the Sichuan-Tibet Highway[J] MODERN TUNNELLING TECHNOLOGY, 2012,V49(6): 108-115
2012, Vol. 49 