中老铁路某隧道盐岩工程地质特征研究  

Study on Engineering Geological Characteristics of Saline Rock in a Tunnel on China-Laos Railway

作　　者：陈伟[1,2] 张明红[2] 张莹[2] 林玲[2] CHEN Wei;ZHANG Minghong;ZHANG Ying;LIN Ling(Southwest Jiaotong University,Chengdu 610031;China Railway Eryuan Engineering Group Co.,Ltd.,Chengdu 610031)

机构地区：[1]西南交通大学,成都610031 [2]中铁二院工程集团有限责任公司,成都610031

出　　处：《现代隧道技术》2023年第5期234-242,253,共10页Modern Tunnelling Technology

基　　金：中国铁路经济规划研究院基金(2021YJJ06)。

摘　　要：盐岩地质对隧道工程建设及运营极为不利,依托中老铁路某隧道穿越厚层氯化物盐岩的工程实例,对其工程地质特征进行研究。先根据含盐量将盐岩工程段分为低含盐段与高含盐段,再采用薄片鉴定、X-衍射、强度试验、水质分析、溶蚀与膨胀性试验对不同含盐段进行测试,定量研究其物理、力学、水化学、溶蚀与膨胀等工程地质特性。结果表明,该段盐岩矿物成分主要为石盐(NaCl);高含盐段盐岩抗压强度显著小于低含盐段与不含盐段的抗压强度;地下水中主要阴阳离子来源于盐的溶解,随含盐量的增加,地下水的环境作用等级逐渐增强;盐岩具有溶蚀性,高含盐段最大上溶蚀速度为8.846~10.540 mm/h,平均为9.527 mm/h;盐岩具有膨胀性,在饱和环境中高含盐段盐岩膨胀指标普遍大于不含盐段与低含盐段膨胀指标。隧道建设中应注意采取针对性防治措施,避免工程病害的发生。Saline rock is extremely unfavorable to tunnel engineering.In this study,based on a tunnel passing through thick chloride saline rock on the China-Laos Railway,its engineering geological characteristics are studied.Firstly,the saline rock engineering section is divided into the low salt content section and the high salt content sec⁃tion based on salt content.Then,the sections with different salt contents are tested using thin section identification,X-ray diffraction,strength test,water quality analysis,corrosion and expansibility tests to quantitatively study their physical,mechanical,hydrochemical,corrosion and expansibility and other engineering geological characteristics.The results indicate that the mineral components of the saline rock in this section is mainly rock salt(NaCl).The compressive strength of saline rock in the high salt content section is significantly lower than that of saline rock in the low salt content section.The main anions and cations in the groundwater come from the dissolution of salt,and as the salt content increases,the environmental action level of the groundwater gradually increases.Saline rock is corrosive,and the maximum upper corrosion rate in the high salt content section is 8.846~10.540 mm/h,with an aver⁃age of 9.527 mm/h.Saline rock is also expandable,and in the saturated environment,the expansion indicator of sa⁃line rock in the high salt content section is generally higher than the indicator in the non-saline section and low salt content section.In tunnel construction,targeted prevention and control measures should be taken to avoid the occur⁃rence of engineering defects.

关 键 词：铁路隧道 盐岩地质 抗压强度 溶蚀 膨胀 

分 类 号：U452.11[建筑科学—桥梁与隧道工程]