构造复杂区非煤地层隧道有害气体成因机制及运移模式  

Genetic Mechanism and Migration Mode of Harmful Gases in Non-Coal Strata Tunnel through Tectonic Complex Area

作　　者：苏培东[1] 曹津铭 舒鸿燚 杜宇本 陈浩栋 SU Peidong;CAO Jinming;SHU Hongyi;DU Yuben;CHEN Haodong(School of Geoscience and Technology,Southwest Petroleum University,Chengdu Sichuan 610500,China;China Railway Eryuan Engineering Group Co.,Ltd.,Chengdu Sichuan 610036,China)

机构地区：[1]西南石油大学地球科学与技术学院,四川成都610500 [2]中国中铁二院工程集团有限责任公司,四川成都610036

出　　处：《中国铁道科学》2020年第2期91-98,共8页China Railway Science

基　　金：四川省科技厅应用基础研究项目(19YYJC1060);中国中铁二院工程集团有限责任公司科研项目(科-2018-33-2)。

摘　　要：以位于深大断裂交汇区的大(理)临(沧)铁路红豆山隧道为例,在分析隧道地质环境的基础上,结合隧址区有害气体现场监测和室内试验分析及隧址区断裂构造特征,研究构造复杂区非煤地层隧道内有害气体的成因机制和运移模式。结果表明:隧道内主要有害气体为高浓度CO2和较高浓度H2S,以断裂带及花岗岩蚀变带为运移通道;隧道内有害气体为无机成因气,来源于深部壳幔地层,其中CO2的同位素值在-0.3‰^-8.0‰之间,可判定隧道内有害气体为岩浆-幔源及变质混合成因;隧道穿越的诸多张性断层既可作为储气断裂,也可视为幔源岩浆气向上运移的疏气断裂。Taking the Hongdoushan tunnel of Dali-Lincang Railway at the intersection of deep faults for example,based on the analysis of the geological environment of the tunnel,combined with the on-site monitoring,laboratory test analysis and the characteristics of the fault structure in the tunnel site,the genetic mechanism and migration modes of harmful gases in non-coal strata tunnel in tectonic complex areas were studied.Results show that the main harmful gases in the tunnel are high-concentration carbon dioxide(CO2)and higher-concentration hydrogen sulfide(H2S),which take fault zones and granite alteration zones as migration channels.The harmful gases in the tunnel are of inorganic origins,which come from deep crust and mantle strata.The isotope value of CO2 is between-0.3‰and-8.0‰,it can be concluded that the harmful gases in the tunnel are of magma-mantle origins and metamorphic mixed origins.Many of the extensional faults that the tunnel passes through can be used either as gas gathering faults or gas transmitting faults in the upward migration of mantle-derived magmatic gas.

关 键 词：构造复杂区 非煤地层 隧道 深大断裂 有害气体 成因机制 

分 类 号：U456.33[建筑科学—桥梁与隧道工程]