探地雷达探测地下管线的机理和应用研究

摘要

地下管线无论其内部充填空气、水或其它介质,其介电常数、电导率等物性参数与周围介质均存在明显差异,具备探地雷达探测的地球物理前提.从探地雷达探测地下管线的极性分析入手,通过建立金属和非金属管线的正演数值模型,研究探地雷达电磁波在金属管线、非金属管线和组合管线中的传播机制.结合实际探测的地下管线探地雷达特征图谱,从反射波波形、极性、同相轴、电磁波能量吸收和衰减等方面分析探地雷达探测地下管线的波谱特征,建立探地雷达探测金属和非金属管线的识别方法,为准确探测地下管线起到很好的指导作用.%The dielectric constant and electical conductivity of underground pipeline are obviously different with surrounding medium,regardless of its internal filling air,water or other medium.It is prerequisite with the ground penetrating radar for detecting underground pipelinse.This paper analyzes the ground penetrating radar for detecting underground pipelines polarity.Through the establishment of metal and non-metallic pipeline forward numerical model,it focuses the transimission mechanism of GPR electromagnetic wave in metal pipeline,nonmetal pipeline.Combined with the actual detection of underground pipeline ground-penetrating radar feature mapping,it analyzes the spectrum characteristics from the reflection waveform,polarity,phase axis,electromagnetic wave energy absorption and attenuation.Finally,it establishes the identificaion method of GPR detecting metal and non-metallic pipeline.The results play a very good guidance for accurately detecting underground pipelines.