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| Research on the Classification Method of Railway Gas Tunnel |
| KUANG Liang1,ZHANG Jun-yun2, ZHANG Zhen-qiang2 |
| (1.Key Laboratory of Transportation Tunneling Engineering, Ministry of Education, Southwest Jiaotong University, Chengdu, Sichuan 610031, China；2. Southwest Jiaotong University, Chengdu, Sichuan 610031, China) |
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Abstract Abstract：Research purposes： At present, 0.5 m3/min is used as the high and low gas level limit value of the railway tunnel as the absolute gas emission. Nowadays, with the rapid development of high-speed and large section railway gas tunnel, the ventilation mode and process of construction have great changes, this classification method can not be fully applicable to the large section of gas tunnel, it will increase the equipment investment and engineering measures, and result in a waste of investment. A suitable classification method for various section railway gas tunnel was put forward by means of analysis of gas grade classification principle and method of mine and traffic gas tunnel, combined with railway tunnel cross section size, air flow and gas concentration index to meet the use of gas tunnel design and construction. Research conclusions： (1) According to the safety of gas concentration, and combined with the section size of tunnel and ventilation，railway gas tunnel classification method is proposed. Accordingly, the gas grading of Chengdu-Guiyang railway line for passenger traffic were classified, the results can reduce the engineering investment, accelerate the construction progress. (2)The concept of micro-gas tunnel was put forward, the boundary value of the concentration of micro gas and low gas tunnel is 0.1%, and the boundary value of the low gas and high gas tunnel is 0.3%. (3) On the basis of the excavation area, railway tunnel is divided into four levels: class Ⅰ (30 ~ 70 m2)，class Ⅱ (70 ~ 110 m2)，class Ⅲ(110 ~ 140 m2) and class Ⅳ(≥140 m2). (4) The suitable calculation method of gas tunnel classification for 〖JP2〗amount of wind was put forward, the boundary required air volume of micro gas and low gas was calculated by 0.15 m/s 〖JP2〗multiplied by the basal area, the boundary required air volume of low gas and high gas tunnel was calculated by 0.2 m/s multiplied by the basal area. (5) The research results can provide a reference for the design and construction of railway gas tunnel.
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Received: 05 July 2017
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2017, Vol. 34 
