Sponsor(s): China Railway Tunnel Consultants Co.,Ltd.
12 issues per year
Current Issue: Issue 03, 2020
Tunnel Construction was hosted by China Railway Tunnel Consultants Co.,Ltd. It mainly publishes research results and advanced technologies in tunnels and underground engineering and related fields; the content of the publication is based on practical technology, taking into account experiments, research and comprehensive reviews, designing tunnels and underground works in railways and highways, and related institutional projects, Water conservancy projects, geotechnical engineering, engineering blasting, engineering materials, engineering machinery, engineering management and other majors. Domestic and international scientific and technological information and industry trends in related fields.
Tunnel Construction,2020,Vol 40,No. 03
New Yuelongmen Tunnel of Chengdu-Lanzhou Railway passes through the famous Longmen Mountains in China, which has a controlled construction period along the whole railway line. The construction organization of Yuelongmen Tunnel is affected by many factors including unfavorable geology (e.g. high in-situ stress, high temperature, high gas and H2S, large deformation of soft rock, active fault zone and water-rich karst), and secondary geological hazards (e.g. landslide and debris flow after 2018 Wenchuan Earthquake). In addition, the dead-end distance of tunnel construction ventilation in the construction site of No. 3 inclined shaft reaches 8 km, and the section is adjusted due to the “tunnel group effect” of large deformation of soft rock, increasing the out-shift parallel adits, resulting in a “2 + 1 + 1” tunnel structure (four tracks parallel to each other), high-gas ventilation and a sharp increase in difficulties of logistics transportation. These lead to substantial challenges in dynamic control of tunnel construction organization to cope with the features of diversification and complexity. Thus, at the preliminary stage and during the construction of Yuelongmen Tunnel, scientific technologies for dynamic control and management methodologies have been established. Especially, scientific research and integrated innovation based on the existing achievements have been performed in respect of large deformation of soft rock, crossing active fault zone, geological prediction of water-rich karst, ventilation of super long tunnel and logistics organization and transportation. Such studies and innovations have been gradually improved and optimized in the implementation process, which makes the work progress of Yuelongmen Tunnel controllable and effective, and thus provide a useful reference for the construction of similar super long and complex tunnel projects in future.
Tunnel Construction,2020,Vol 40,No. 03
In order to solve the problems of low manual welding efficiency, substantial personnel input and unstable processing quality of the plane mesh of the shield tunnel segment, the FGZH-3 Project of Foshan-Dongguan Inter-city is selected to form the plane mesh of the segment steel cage. The design and optimization of the module’s automatic positioning and forming, horizontal beam automatic blanking and welding device, plane mesh bending and welding device, automatic control system are carried out. The problems of plane mesh bending and welding stress concentration, joint alignment and unstable welding quality are solved through the introduction of plane mesh forming device, internal and external arc bending correction mold and other institutions. The mechanization and automation of the plane mesh of the segment steel cage from the blanking of the steel to the one-time forming are realized, which ensures the stable processing quality of the plane mesh and reduces the labor intensity of workers. The study results can provide guiding significance for promoting the research & development and upgrade of automatic processing equipment for segment steel cages.