摘要
在广西溶蚀晚期喀斯特峰丛地貌区,传统钻探受单点信息局限,且钻探与地面物探因地形高差与接地条件限制难以实施,导致勘察空白,严重制约岩溶隧道地质风险评估。针对复杂地貌勘察瓶颈,研发自主知识产权的半航空频率域电磁法(Ground Air Electromagnetic Method, GAEM)。采用地面发射源与无人机接收系统协同探测,通过GAEM-1系统实现空中高效数据采集。针对时间域电磁法晚期道信号衰减快、探测深度不足且易受噪声干扰的缺陷,创新性地引入频率域多频点激发机制,同步提升探测深度与分辨率,并通过频域信号抗干扰特性保障数据质量。广西河池隧道探测显示:三维电性模型清晰刻画了进出口低洼区和山体内低阻异常带,其展布与断层及历史涌水点高度吻合。半航空频率域电磁法突破复杂地貌勘察限制,多频点激励实现深部岩溶发育区三维成像。建立的"电性-地质"关联模型,为岩溶隧道全周期风险防控提供技术支撑。
In the peak cluster landform area of Guangxi,which is characterized by late-stage Karst dissolution,traditional drilling methods are constrained by single-point nature of data.Additionally,the implementation of drilling and ground geophysical surveys is hindered by topographic elevation differences and poor grounding conditions,resulting in survey gaps that severely restrict geological risk assessment for Karst tunnels.To address the bottleneck in surveying complex landforms,a semi-airborne frequency-domain electromagnetic method with independent intellectual property rights,known as the gound-air electromagnetic method(GAEM)has been created.This innovative approach employs coordinated detection through ground-based transmitters and drone-borne receiving systems,achieving efficient aerial data acquisition via the GAEM-1 system.To address the shortco mings of time-domain electromagnetic methods characterized by fast attenuation of late-time signals,insufficient detection depth,and susceptibility to noise interference,we innovatively introduced a frequency-domain multi-frequency excitation mechanisms,simultaneously enhancing both detection depth and resolution.At the same time,the inherent anti-interference characteristics of frequency-domain signals ensure data quality.The application in the Hechi Tunnel project in Guangxi demonstrates that the 3D resistivity model clearly delineates low-resistivity anomaly zones within low-lying areas at tunnel entrances and within mountains,with their spatial distribution showing high consistency with fault structures and historical water gushing points.The semi-airborne frequency-domain electromagnetic method breaks through the limitations of complex terrain surveys,while multi-frequency excitation enables 3D imaging of deep Karst development zones.The established“electrical-geological”correlation model provides crucial technical support for comprehensive risk prevention and control throughout the entire lifecycle of Karst tunnel projects.
作者
王仕兴
赵思为
陈泓浩
杨均
Wang Shixing;Zhao Siwei;Chen Honghao;Yang Jun(China Railway Eryuan Engineering Group Co.LTD,Chengdu Sichuan 610031,China;Workstation of Chinese Geophysical Society at China Railway Eryuan for Academician and Experts,Chengdu Sichuan 610031,China;Chengdu Huafeng Engineering Survey and Design Co.LTD,Chengdu Sichuan 610031,China)
出处
《工程地球物理学报》
2025年第5期342-350,共9页
Chinese Journal of Engineering Geophysics
基金
西藏自治区科技计划项目(编号:XZ202402ZD0003)。
关键词
岩溶发育地区
隧道勘察
半航空频率域电磁法
Karst development areas
tunnel investigation
semi-airborne frequency-domain electromagnetic method
