Application and Study of Three in One Gas Forecast Technology in Non-excavated Area of Gas Tunnel

Abstract

The super colossal gas explosion accident happened in Dong-Jiashan tunnel of Du (Jiangyan) - Wen (Chuan) expressway, 2005. It led 44 people to die and shocked at home and abroad. From then on, increasing numbers public and the related functional sectors have paid more attention to gas safety managements during the gas tunnel excavated. It is well known gas existence in stratum should meet three necessary conditions, gas sources, channels and sealing conditions. The gas forecast technology by TGP geophysical, geological drilling and borehole gas emission content estimate composed can predict the gas sources and gas channels and gas sealing conditions. The borehole gas emission content estimate can predict the gas content in non-excavated area of gas tunnel. It is successfully applied to the non-excavated area of Le-Tunnel, the gas emission content: 0.164m3/min<0.5m3/min. The forecast segment belongs to the low gas work area. Practice has proved that the three in one gas forecast technology can offer a further reference method for the same type of gas tunnel prediction technology.