隧道中硫化氢有毒气体分级防护体系

为解决目前隧道中硫化氢有毒气体防护无规范标准可依、防护措施单一(通风稀释)或过度防护等问题,针对隧道空间较封闭和不能长时间停工等特点,依据隧道最大通风风速和其他行业硫化氢作业环境浓度,首次提出了隧道内硫化氢按绝对涌出量为指标的分级防护体系,并在米仓山隧道中得到成功运用。当隧道内硫化氢气体绝对涌出量每分钟小于25 L时为Ⅰ级防护,采取通风稀释、超前钻孔探测、硫化氢检测和结构封堵等措施;当隧道内硫化氢气体绝对涌出量每分钟在25 L和78 L之间时为Ⅱ级防护,在Ⅰ级防护的基础上增加个体防护措施,必要时可在含硫化氢气体地层中钻孔预排放和注入碱液吸收;当隧道内硫化氢气体绝对涌出量每分钟大于78 L时为Ⅲ级防护,须短暂停工躲避,工人向含硫化氢气体地层中注入碱液和增加钻孔排放时应佩戴全面罩携气式或供气式空气呼吸器。研究成果为今后含硫化氢气体隧道的修建和制订行业规范提供技术支撑。

Classification Prevention System of Hydrogen Sulfide Toxic Gas in Tunnel

The problems that there is no standard to protect the poisonous gas of hydrogen sulfide in the tunnel at present, the protective measures are single (ventilation dilution) or transitional protection were researched. According to the characteristics that the tunnel space is closed and can not be shut down for a long time, a hierarchical protection system for hydrogen sulfide in tunnels based on absolute emission is used as an indicator. It has been successfully applied in the Micangshan tunnel. When the absolute emission of hydrogen sulfide gas in the tunnel is less than 25 L/min, it is Level I protection, and measures such as ventilation dilution, ahead drilling detection, hydrogen sulfide detection and structural plugging are taken. When the absolute emission of hydrogen sulfide gas in the tunnel is between 25 L/min and 78 L/min, it is Level II protection, and individual protection measures are added on the basis of Level I protection. If necessary, it can be pre-discharged and injected with lye in the hydrogen sulfide-bearing gas formation. When the absolute emission of hydrogen sulfide gas in the tunnel is greater than 78 L/min, it is Level III protection. When workers inject alkali solution into the formation containing hydrogen sulfide gas and increase the discharge of the hole, they shall wear a full mask air carrying or air-supplied respirator. The research results provide technical support for the construction of the hydrogen sulfide gas tunnel and the formulation of industrial specifications in the future.