探地雷达在多年冻土区正演模型研究及应用

通过探地雷达在多年冻土区的应用条件的分析,结合正演模拟和实例勘察,对比分析探地雷达对多年冻土区厚层地下冰的分布、埋藏深度、赋存情况以及对冻土类型的识别的有效性。研究结果表明,厚层地下冰与周围地质体存在巨大的介电常数差异,雷达波的相位特征、振幅大小、反射波和反射波组都出现较大的不同,使得探地雷达能有效地勘察厚层地下冰的各种特征;同时,对不同类型的冻土,因冰晶体的赋存情况及分布不同,结合坑探、钻探等其他地质勘察手段,也能有效地区分。

THE STUDY AND APPLICATION OF THE GROUND PENETRATION RADAR TO THE FORWARD MODELING OF PERMAFROST AREA

Based on an analysis of the applied condition of Ground-Penetrating Radar in permafrost areas in combination with the forward modeling and practical examples,the authors conducted researches on the effectiveness of applying the ground penetrating radar to surveying the distribution,burial depth,storage situation of the thick layer subsurface ice and types of the permafrost in the permafrost area.The results show that remarkable difference in the permittivity exists between the thick layer subsurface ice and the surrounding geological bodies,resulting in the difference of phase characteristics,amplitudes,reflected waves and reflected wave groups of radar waves.The ground-penetrating radar is thus effective in surveying different characteristics of the thick layer subsurface ices.As for the ice-poor permafrost and ice-bearing permafrost,the ground-penetrating radar can also effectively distinguish various permafrost situations in combination with drilling exploration and some other exploration methods due to the difference existent in the storage situation and the distribution of ice crystals in the permafrost layer.