孤石形状与岩土介质对孤石探测的影响研究

采用现场试验和数值模拟相结合的方法,针对不同孤石形状、不同周围岩土介质对地质雷达探测孤石结果的影响进行研究。结果表明:不同形状孤石的雷达波形反射曲线形状有差异,其中球状孤石的反射波形大致为一条双曲线,且曲线较为平滑规则,而块状孤石的反射波形为左右两条双曲线与前部扁平线的组合形状;球状和块状孤石反射曲线中间反射能较大,而曲线两侧翼部反射能较小;球状与块状孤石的反射弧跨度随着截面尺寸的增加呈线性增长,且在相同截面尺寸下两者大致相同;在砂土介质中,孤石处的雷达反射波形比在黏土介质中明显,故周围岩土介质对地质雷达探测孤石结果的准确性有一定的影响。

Research on Influence of Boulder Shape and Rock Soil Medium on Boulder Detection

Combining the field test and numerical simulation,the influence of different boulder shapes and surrounding rock medium conditions on the georadar detection results is studied.Results show that shapes of the radar wave curves are different on different shapes of boulders.When boulder shape is spherical,shape of the radar wave curves is a hyperbolic curve which is smooth and regular.When boulder shape is massive,shape of the radar wave curves is a combined shape that two hyperbolicon curves on both sides are combined with a straight line in front section.Reflected energy of spherical and massive boulders is larger in the intermediate position,and the curve reflected energy is smaller at both sides.The reflex arc span of spherical and massive boulders increases linearly with the cross-section dimension increasing.Their sizes are virtually equal in the same cross-sectional dimension.The boulder radar reflection waveforms in the sand are more obvious than that in the clay.Therefore,surrounding rock and soil medium has a certain impact on the accuracy of results when the georadar is used to detect the boulder.