地铁地下工程中应用地震波CT技术探测孤石的参数选择  

Parameter Selection for the Application of Seismic Wave CT Technology in Detecting Isolated Rocks in Subway Underground Engineering

作　　者：胡晓娟 HU Xiaojuan(Geological Engineering Survey in Fujian Province,350002,Fuzhou,China)

机构地区：[1]福建省地质工程勘察院,福州350002 [2]自然资源部丘陵山地地质灾害防治重点实验室,福州350002

出　　处：《城市轨道交通研究》2023年第11期181-185,193,共6页Urban Mass Transit

基　　金：福建省自然资源科技创新项目(KY-090000-04-2021-003);福建省科技计划项目(2015Y0044)。

摘　　要：目的:地震波CT(计算机辅助层析成像)技术中,采用的不同探测参数(钻孔间距、检波点距、激发点距),对地铁工程中地下孤石探测结果的精确度有直接的影响,需要合理选择探测参数。方法:阐述了地震波CT技术的基本原理,以福州地铁1号线某车站的工程实际为例,在相同的探测条件下采用3种钻孔间距(4.6 m、10.4 m及15.0 m)进行地震波CT探测,并对比分析探测结果。在此基础上,在钻孔间距分别为14.5 m和10.5 m两种工况下,选取了4种检波点距和检波点距的组合方式,对探测结果进行了对比分析。结果及结论:选用较小钻孔间距(取值为4.6 m及10.4 m)时更能精确地反映地下孤石的分布形态及具体分布位置。选用较大钻孔间距(取值为15.0 m)时探测得到的地下孤石分布范围与实际分布情况相比偏大,且形态特征较模糊。与激发点距与检波点距取值较大(二者均取2.0 m)相比,取值较小时(二者均取0.5 m或1.0 m)地下孤石的探测分辨率更高。地震波CT合理的参数取值为:钻孔间距取10.0 m,激发点距和检波点距均取1.0 m。Objective:The choice of different detection parameters(borehole spacing,receiver spacing,source spacing)in seismic wave CT(computer-aided tomography)technology has a direct impact on the accuracy of detecting underground boulders in subway engineering.It is important to select the detection parameters reasonably.Method:The basic principle of seismic wave CT technology is explained.Taking an actual engineering example of a station on Fuzhou Metro Line 1,the seismic wave CT detection is conducted using three different bore-hole spacing(4.6 m,10.4 m,and 15.0 m)under the same detection conditions,and the detection results are compared and analyzed.Based on this,under two different bore-hole spacing conditions(14.5 m and 10.5 m),four combinations of receiver spacing are selected and compared to analyze the detection results.Result&Conclusion:The use of smaller bore-hole spacing(4.6 m and 10.4 m)can reflect the distribution pattern and specific locations of isolated rocks more accurately.When using larger bore-hole spacing(15.0 m),the detected distribution range of isolated rocks is larger than the actual distribution,and the morphological characteristics are more blurred.Compared to larger source and receiver spacing values(both 2.0 m),smaller values(both 0.5 m or 1.0 m)provide higher detection resolution for isolated rocks.The reasonable parameter values for seismic wave CT are:10.0 m for bore-hole spacing,1.0 m for source spacing and receiver spacing both.

关 键 词：地铁地下工程 孤石探测 地震波层析成像技术 探测分辨率 

分 类 号：TU94.3[建筑科学—建筑技术科学]