Abstract Certain sections in the running tunnel between the New Warf Street Station to Honglian Village South Station of Chengdu Rail Transit Line 19 Phase II Project are high-gas bearing tunnels. In order to study the spatial distribution characteristics, recharge mode and fugitive pattern of gas in high-gas bearing strata, this paper uses test methods, such as stratified detection, fugitive gas monitoring and borehole drainage, etc., to analyze whether the gas concentration in tunnels can be reduced in advance through ventilation and drainage, with the aim to provide technical support for the design and construction of tunnels in high-gas bearing sections. The test results show that the gas in the strata of the studied area mainly accumulates in the form of gasbags, which are recharged from the lower Sumatou gas field through faults; the option to reduce the gas concentration in the tunnels in the studied area through ventilation and drainage measures is feasible, with a maximum impact radius of 5 m for the drainage boreholes.
Abstract：
Certain sections in the running tunnel between the New Warf Street Station to Honglian Village South Station of Chengdu Rail Transit Line 19 Phase II Project are high-gas bearing tunnels. In order to study the spatial distribution characteristics, recharge mode and fugitive pattern of gas in high-gas bearing strata, this paper uses test methods, such as stratified detection, fugitive gas monitoring and borehole drainage, etc., to analyze whether the gas concentration in tunnels can be reduced in advance through ventilation and drainage, with the aim to provide technical support for the design and construction of tunnels in high-gas bearing sections. The test results show that the gas in the strata of the studied area mainly accumulates in the form of gasbags, which are recharged from the lower Sumatou gas field through faults; the option to reduce the gas concentration in the tunnels in the studied area through ventilation and drainage measures is feasible, with a maximum impact radius of 5 m for the drainage boreholes.
TANG Ouling1 CHEN Xinghai1 CHANG Xingwang1 SU Peidong2
.Study on the Occurrence Characteristics and Drainage Tests of Shallow Natural Gas in High-Gas Bearing Tunnels in Non-Coal Measure Strata[J] MODERN TUNNELLING TECHNOLOGY, 2021,V58(5): 140-146
2021, Vol. 58 