摘要
深部隧道建设受到各种地质活动的影响,其中地热活动严重影响了施工安全和效率,而目前研究缺乏对地热成因的实例研究。以拟建新疆某高速公路隧道(最大埋深1348 m)为例,通过物探、钻探、水文地球化学、热红外遥感、无人机等方法得到该隧道工程地质、水文地质特征,对隧道附近温泉分布和高温等特征进行了研究。结果表明:温泉仅分布在F36与F37断裂交汇处EN方向的沟谷地区;研究区存在低电阻岩体破碎带,尤其分布在断层和温泉点附近;同时温泉水样矿化度与阿尔先河水相比相差很大,温度也略高于周围地层。研究得出研究区内地热水形成机制:地热水并非由较近的阿尔先河水补给,而是由大气降水和3000 m外的冰雪融水补给,地下水汇聚到F35、F36、F37断层交汇点附近在地下约200 m处遇深部热源加热,高温地下水沿2个断层交汇处裂隙向地表流动。同时采用了层次分析法对该隧道拟建线路开展热害评估,将断层、地温、隧道涌水、围岩岩性4个因素作为主要影响因子,评估结果表明,B8线路分值最低,说明其受热害影响程度最小,判断B8线为最优线路。本研究揭示了深埋隧道地热活动的形成机制与分布规律,为高寒山区隧道热害防治提供了科学依据。
[Objective]Deep tunnel construction is impacted by various geological processes,with geothermal activity significantly affecting construction safety and efficiency.However,case studies specifically revealing geothermal genesis remain scarce.[Methods]An integrated approach employing geophysical exploration,drilling,hydrogeochemical analysis,thermal infrared remote sensing,and UAV surveys was utilized to characterize the engineering geological and hydrogeological conditions of a planned expressway tunnel in Xinjiang(maximum burial depth:1348 m),with specific focus on adjacent hot springs and high-temperature phenomena.[Results]Results show that hot springs are exclusively distributed within the valley area northeast of the intersection between the F36 and F37 faults.Low-resistance fractured rock masses are presented within the study area,particularly concentrated near fault zones and hot spring locations.Additionally,hot spring water samples exhibit significantly higher mineralization compared to the Arxian River water,along with slightly elevated temperatures relative to the ambient strata.[Conclusion]Based on aformentioned findings,the geothermal water formation mechanism within the study area is proposed.Recharge occurs not from the proximal Arxian River,but from atmospheric precipitation and meltwater sourced from distal glaciers/snowfields approximately 3 km away.These recharged groundwaters converge near the F35-F36-F37 fault intersection,where it is heated at about 200 m depth by a deep-seated heat source before ascending along fractures in the fault zone towards the surface.Furthermore,employing the Analytic Hierarchy Process(AHP)for thermal hazard assessment of present planned tunnel alignments-considering faults,geothermal gradient,water inflow potential,and surrounding rock lithology as key factors-identified alignment B8 as optimal,evidenced by its lowest AHP score indicating minimal thermal hazard impact.This study elucidates the formation mechanisms and distribution patterns of geothermal activity in deep-buried tunnels,providing a scientific basis for thermal hazard mitigation in high-altitude permafrost regions.
作者
柴琛
周昌
夏钊
王修春
梁龙飞
董青红
CHAI Chen;ZHOU Chang;XIA Zhao;WANG Xiuchun;LIANG Longfei;DONG Qinghong(School of Resources and Earth Sciences,China University of Mining and Technology,Xuzhou Jiangsu 221116,China;Hunan Water Planning and Design Institute Co.,Ltd.,Changsha 410008,China)
出处
《地质科技通报》
北大核心
2025年第4期304-315,共12页
Bulletin of Geological Science and Technology
基金
新疆维吾尔自治区重点研发计划项目(2022B03017,2021B03004-3)。
关键词
深埋隧道
地热成因
断层控制
热害
新疆
deep-buried tunnel
geothermal genesis
fault control
thermal hazard
Xinjiang
