沥青心墙压实度的探地雷达探测研究

沥青心墙是水利水电工程的一种重要的防渗形式,其质量直接关系到工程的安全.压实度是评价其质量的重要指标,常采用取芯后实验室来测定,虽然探测结果可靠,但破坏性大、周期性长以及连续性差.我们采用探地雷达方法来评价沥青心墙的压实度.为消除沥青心墙的侧壁和两侧的堆石对探测结果的影响,本文模拟了雷达波在沥青心墙中传播,得出没有侧壁和堆石反射波影响的有效探测深度.并利用实测数据提取沥青心墙的雷达波属性如振幅、主频以及瞬态谱等,结合采样获得的孔隙度和密度,得出其与属性参数间的关系.研究表明,这种方法可以直观、快速、连续的反映心墙压实度变化,为工程质量的检测提供很好的依据.

Using ground penetrating radar to detect asphalt core-wall's compactness

Asphalt core-wall is an important form for seepage control in water resources and hydropower engineering and its quality directly relates to the safety of engineering. The conventional evaluation meth- od is sampling and detecting in lab. Its advantage is reliability and its disadvantages are destructiveness, l- ong periodicity and discontinuity. So an effective method is of urgent need. Ground Penetrating Radar (GPR) has the advantages in non-destructive, rapid and high accuracy. GPR can not detect core-wall of asphalt concrete very well now because the core-wall is very inhomogeneous and has strong reflected waves of both sides of the int- erface. We simulate the radar wave propagating in the core-wall and yield effective detect depth without effects f- rom rocks beside the asphalt. According to results of simulation, we get attribution parameters such as amplit- ude, phase and frequency from GPR data. We analyze the relationship between density and porosity of the sample and the parameters of attributions. Using this formula we can evaluate the project quality.