摘要
将TSP、地质雷达技术用于千岛湖配水工程灰岩区隧洞超前预报,简述了两种物探方法的原理,统计了完整性较好的灰岩与砂质岩对应的TSP指标范围,采用有限差分法模拟了地震波在隧洞前方遭遇大型溶洞时的波场特性,总结了岩性变化、溶洞、溶蚀带对应的物探异常规律。结论如下:地质雷达是溶洞、溶蚀带探测较理想的手段,其电磁异常特征表现为反射波振幅强,同相轴错断或呈双曲线状,并伴随一定程度的多次反射,含泥溶腔主频较空腔偏低,但多大于50MHz;同等质量级别下灰岩对应TSP各物理力学指标较粉砂岩或泥质砂岩偏好;大型空腔对应TSP纵波波速、密度及杨氏模量偏低,TSP对小型溶腔或溶蚀带探测敏感度较差,有时仅体现为反射层密集。
This paper presents an application of TSP and ground penetrating radar(GPR)to advanced prediction of a tunnel in the limestone area for the Thousand Island Lake-Hangzhou water transfer project.A brief description of the principle of the geophysical methods is given firstly.Then we calculate the range of TSP indexes corresponding to the better integrity of limestone and sandstone.Next we use the finite difference method to simulate the wave field characteristics for seismic waves encountered in a large karst cave in front of the tunnel.Lastly,we summarize the laws of geophysical anomalies corresponding to lithologic changes,karst caves and dissolution layers.Results show that GPR is an ideal tool for the detection of karst caves and dissolution layers,from which electromagnetic anomalies have the characteristics of strong reflection amplitude,broken or hyperbolic events as well as accompanying multiple reflections.The main frequency of mud-bearing karst caves is relatively lower than hollow cavity but both are usually greater than 50MHz.The physical and mechanical indexes of TSP for limestone are better than siltstone or argillaceous sandstone under the same classification of rock mass basic quality.TSP anomalies of large hollow cavities show that the values of longitudinal wave velocity,density and Young modulus are lower.TSP is less sensitive to the detection of small-scale karst caves or dissolution layers,and sometimes the anomalies merely exhibit dense reflections.
作者
李俊杰
张红纲
王伟
何建设
李剑强
郭佳豪
LI Junjie;ZHANG Honggang;WANG Wei;HE Jianshe;LI Jianqiang;GUO Jiahao(Zhejiang Design Institute of Water Conservancy and Hydroelectric Power,Hangzhou,Zhejiang 310002;State Key Laboratory of Resources and Environmental Information System,Institute of Geographic Sciences and Natural ResourcesResearch,Chinese Academy of Sciences,Beijing 100101)
出处
《地质与勘探》
CAS
CSCD
北大核心
2019年第6期1452-1462,共11页
Geology and Exploration
基金
国家自然科学基金项目(编号:41641040)
浙江省水利厅科技项目(编号:RC1729)联合资助
关键词
TSP
地质雷达
千岛湖配水工程
灰岩
超前预报
TSP
ground penetrating radar
Thousand Island Lake water transfer project
limestone
advanced prediction
