铁路隧道壁后煤层自燃灭火关键技术研究

Research on key technology of coal seam self-ignition and fire extinguishing behind railway tunnel wall

铁路隧道壁后浅部煤层复杂地质构造区存在隐蔽小煤矿自燃问题,火势蔓延对铁路隧道结构安全构成严重威胁,本文以阴塔至火山铁路线火山隧道火区治理为研究目标,通过隧道衬砌温度扫描、地质雷达探测与地面钻孔验证相结合的监测手段,准确圈定小煤矿明火对隧道的直接与间接影响范围,同时结合强隆起断褶构造区地质特征与铁路隧道结构安全的特殊要求,制定了以施工地面措施孔充填矿用大骨料隔离材料构筑隧道隔离条带为主的火区治理方案,施工了42个措施孔,重点充填了隧道403~415 m区段,累计充填隔离材料672 t。研究结果表明,经过治理,极大遏制区域内火情,隧道衬砌表面温度总体稳定在33℃以下,CO浓度降至9 ppm,初步达到了预期目标,有效地延长了火山隧道的服务年限。

In order to effectively prevent and control the spontaneous combustion of hidden small coal mines in the complex geological structure area of shallow coal seams and the serious threat posed by the spread of fire to the structural safety of railway tunnel,the direct and indirect impact range of small coal mine open fire on the tunnel is accurately delineated through the monitoring means of tunnel lining temperature scanning,geological radar detection and ground drilling verification,At the same time,combined with the geological characteristics of the strong uplift fault-fold structural area and the special requirements for the structural safety of railway tunnel,a fire area treatment scheme based on filling the mining large aggregate isolation material with the construction ground measure hole to build the tunnel isolation strip is formulated.42 measure holes are constructed before and after,focusing on filling the 403-415 m section of the tunnel,with a cumulative filling of 672 t of isolation material.The field application results show that after treatment,the fire situation in the area is greatly restrained,the tunnel lining surface temperature is generally stable below 33℃,and the CO concentration is reduced to 9 ppm,which initially achieves the expected goal and effectively prolongs the service life of volcanic tunnel.