Sponsor(s): China Railway Tunnel Consultants Co.,Ltd.
12 issues per year
Current Issue: Issue 06, 2019
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,2019,Vol 39,No. 06
Targeted to the issue of lacking of systematic design standards for thermal insulation and drainage facilities of railway tunnels in cold regions, the authors propose the method of design division of railway tunnels in cold regions based on the division of cold regions, the current technical status of thermal insulation and drainage in tunnels, and the investigation on some tunnel freezing damage cases in northeastern China and the northern part of North China. Through analyzing the application conditions of the thermal insulation and drainage facilities and combining the measured temperatures in the operating tunnels and drainage facilities, the authors propose the suggested length for the thermal insulation and drainage facilities of tunnels in cold regions in different divisions. The results show that: (1) railway tunnels in cold regions may be classified into 5 divisions based on annual average temperature and average temperature in the coldest month; (2) the elevated thermal-insulation ditch only adapts to the cold regions with a higher temperature; (3) an effective measure for thermal insulation and drainage in cold regions is to embed ditches into structures within a certain range from the portal; (4) the ditches may be arranged in structures for the trunk section of long tunnels equipped with thermal insulation measures; (5) for the tunnels with the necessary conditions available, the double spur grade and a steep gradient in the longitudinal slope may be applied, which is beneficial to improving drainage conditions and preventing the ditch from freezing.
Tunnel Construction,2019,Vol 39,No. 06
Construction of submerged floating tunnel (SFT) is one of the major solutions for fjord crossing projects and deep sea crossing projects in the future. Aimed to solve the key problems in SFT construction, the authors present an overview on the progress of the researches made in China and other countries in recent years on cross-section of SFT, dynamic response of SFT segment structure, vortex-induced vibration of anchor cable, testing technique and applicability of SFT, summarize the critical problems in the dynamic response research of SFT structures and make prospect on the trend of further SFT research. Conclusions are drawn as follow: (1) In the aspect of cross-section design, SFT with ear-shaped or elliptical cross-section has good stability in the complex environment of flowing water, with factors comprehensively considered, such as cross-section of SFT segment structures, buoyancy-weight ratio and layout. (2) In the aspect of dynamic response of structures and anchor cables, the current research methods are mainly based on theoretical derivation and numerical simulation, and poorly rely on model-based testing technique; therefore, it is necessary to perform model tests under combined loads from the environment, traffic and SFT, for mutual check between the theoretical analysis and numerical model. (3) In the aspect of applicability, it is necessary to build small SFT in feasible water conditions to make research on the physical SFT in the static waters, to identify problems and to lay a foundation technically for building large SFTs in the complex sea conditions.