Abstract The exit section of the Gaoqiao Tunnel on the Zhengzhou-Xi'an Passenger Dedicated Line passing under the existing Nantongpu railway is characterized by the technical difficulties of a super-shallow depth, a large cross-section, new loess geology and a small passing angle. Since the shallow loess tunnel is prone to large deformations and abrupt collapse, a design concept using a pipe roof, double-layer support and bench method was ultimately adopted, ensuring the safety of tunnel construction, continued operation of the existing line, and adherence to the construction schedule. Additionally, such measures as reinforcement of the existing railway from the surface, 100m long pipe-roof, double-layer anchor and shotcrete support and rapid invert enclosing were utilized. This paper introduces the scheme comparison and site construction of a large loess tunnel beneath an existing railway, analyzes the testing conditions and evaluates the applicability of the double-layer support and bench method for this type of tunnel and presents relevant technical points.
Abstract：
The exit section of the Gaoqiao Tunnel on the Zhengzhou-Xi'an Passenger Dedicated Line passing under the existing Nantongpu railway is characterized by the technical difficulties of a super-shallow depth, a large cross-section, new loess geology and a small passing angle. Since the shallow loess tunnel is prone to large deformations and abrupt collapse, a design concept using a pipe roof, double-layer support and bench method was ultimately adopted, ensuring the safety of tunnel construction, continued operation of the existing line, and adherence to the construction schedule. Additionally, such measures as reinforcement of the existing railway from the surface, 100m long pipe-roof, double-layer anchor and shotcrete support and rapid invert enclosing were utilized. This paper introduces the scheme comparison and site construction of a large loess tunnel beneath an existing railway, analyzes the testing conditions and evaluates the applicability of the double-layer support and bench method for this type of tunnel and presents relevant technical points.
WANG Xin-Dong
.Design and Construction of the Gaoqiao Tunnel on the Zhengzhou-Xi'an Passenger Dedicated Line Passing Under the Existing Railway[J] MODERN TUNNELLING TECHNOLOGY, 2012,V49(1): 132-137
2012, Vol. 49 