紫金山金-铜矿露天采矿场地下不明空区的地质雷达探测

Ground penetrating radar detection of underground unknown mining cavities in the open-pit at the Zijinshan Au-Cu deposit

采用先进的地球物理技术探明露天采矿场地下不明空区的分布情况,准确确定其平面分布范围、顶面埋深及空间高度,对保障露天采矿作业的安全进行、预防突发性事故的发生具有十分重要的意义。运用地质雷达对福建紫金山金铜矿露天采矿场地下不明空区进行探测,在两个不同探测区块共完成18条探测剖面,剖面线总长近4km;经处理后的实测地质雷达剖面具有高清晰度、高分辨率,能准确反映地下各种不同规模的不明采空区的属性、平面位置、顶板埋藏深度、空区大致高度;地质雷达探测共查明较大空区异常55个。采用50MH z天线的地质雷达系统在该露采场的有效探测深度可以达40m以上。在露天采矿场,地质雷达探测受矿区地形条件及环境影响很小,可直接在岩(矿)石表面进行,不受第四系覆盖层对雷达波衰减吸收的影响。因此,地质雷达非常适应露天采矿场地下采空区的探测及定位。

It is very significant for keeping safe mining in open pit and preventing sudden accident by accurately defining distributing area of ore field, roof depth and space heights through applying advanced geophysical technology to detect the underground unknown mining cavities in open pit. Using ground pentrating radar （GPR） to detect the underground unknown mining cavities in open pit in the Ziiinshan Au--Cu deposit of Fujian Province, 18 detecting profiles with their total length of 4km in two different detecting blocks have been finished. The processed GPR profiles with high clarity and resolution can reflect exactly the attributes, plane location, roof depths and approximate heights of the cavities. 55 larger scale unknown cavities have been revealed by GPR. GPR system with 50MHz antennas can detect effectively the depth of more than 40m in this open pit. GPR would be little affected by landform condition and environment in open pit, and it can be used on rock surface directly without any absorbing attenuation of radar waves from Quaternary overburden. Inhence, GPR is very suitable for the detection and location of the under ground unknown mining cavities in open pit.