川西复杂隧道特殊瓦斯灾害成因及特征研究  

Study on the Causes and Characteristics of Special Gas Disasters in Complex Tunnels in Western Sichuan

作　　者：袁传保[1] 张广泽[1] 宋章[1] YUAN Chuanbao;ZHANG Guangze;SONG Zhang(China Railway Eryuan Engineering Group Co.Ltd,Chengdu,Sichuan 610031,China)

机构地区：[1]中铁二院工程集团有限责任公司,成都610031

出　　处：《铁道工程学报》2023年第8期29-34,共6页Journal of Railway Engineering Society

基　　金：中国铁路总公司科技研究开发计划课题(2021YIJ06);中铁二院工程集团有限责任公司科研项目(KDNQ202006,KDNQ202008)。

摘　　要：研究目的:瓦斯是严重的隧道施工灾害,尤其在非常规煤系地层区修建隧道时,对瓦斯往往没有充分的认识和准备,瓦斯灾害危害性更大。在建成兰铁路位于川西复杂地质区域,构造运动强烈、地层岩性纷杂,多个不同构造单元的隧道在元古代-中生代地层出现非常规瓦斯气体涌出事件,瓦斯成因复杂特殊,机理多样,涌出时效特征不一。研究结论:(1)瓦斯涌出地层可归纳为非煤地层、类煤地层;(2)涌出机理可归纳为发震断裂平面补给型、地震诱发深部型、古地层构造变质型;(3)地震构造型瓦斯多为外生游离型,分布集中,压力低,流量小,涌出曲线呈无序波状,具时间衰减性及空间变异性;构造变质型瓦斯多为自生吸附型,分布同地层,压力较高,流量大,涌出曲线呈阶坡状,具有稳定性和局部喷涌特点;(4)本研究结论可为类似瓦斯隧道工程的瓦斯灾害研究提供借鉴。Research purposes:Gas is a serious disaster in tunnel construction.Especially when constructing tunnels in unconventional coal bearing strata,there is often insufficient understanding and preparation for gas,so the harm of gas disasters is greater.The Chengdu-Lanzhou Railway is located in a complex geological area in western Sichuan,with strong tectonic movement and diverse stratigraphic lithology.Multiple tunnels with different structural units have experienced unconventional gas emission events in the Proterozoic-Mesozoic strata.The gas genesis is complex and special,with diverse mechanisms and varying emission time characteristics.Research conclusions:(1)The gas emission formation can be divided into non-coal formation and coal-like formation.(2)The emission mechanism can be summarized as the plane recharge type of seismogenic fault,the deep type induced by earthquake,and the paleostratigraphic structural metamorphic type.(3)The seismic tectonic gas is mostly exogenous and free type,with concentrated distribution,low pressure,small flow,disordered emission curve,time decay and spatial variability;The tectono-metamorphic gas is mostly autogenous adsorption type,distributed in the same stratum,with high pressure,large flow,and sloping emission curve,with stability and local gushing characteristics.(4)The research conclusion can provide reference for the research of gas disaster in similar gas tunnel projects.

关 键 词：瓦斯隧道 成因机制 非煤地层 活动构造 

分 类 号：P642[天文地球—工程地质学] U453.1[天文地球—地质矿产勘探]