基于Curvelet变换的隧道裂隙水GPR数据处理研究

Processing of GPR data in tunnel fissure water based on Curvelet transform

应用地质雷达探测隧道内部裂隙水的分布状况时,受隧道钢筋网的影响以及噪声干扰,导致探测信号中弱有效信号难以识别。Curvelet变换可以对二维信号从频率、角度和空间位置实现有效反射波和干扰波的分离及降噪处理,应用Curvelet变换对含钢筋网干扰的裂隙水模型的探地雷达模拟数据进行波场分离和降噪处理,在压制直达波、去除钢筋层反射信号及多次反射的基础上,可以有效地提取出含裂隙水所引起的反射波信号。将该方法应用到汝郴高速某隧道实测探地雷达数据中,较好地去除了钢筋层反射信号的影响,准确地判断出了裂隙水的空间分布位置,证明了所提出方法的有效性。

When we detect the distribution of fissure water in tunnel with ground penetrating radar,it is hard to identify the weak effective signal because of the influence of mesh reinforcement and noise.Curvelet transform can achieve effective wave field separation and denoising of two-dimensional signal from the frequency,angle and spatial location.The Curvelet transform is applied to wave field separation and signal denoise processing by using of GPR simulated data from fissured water which is disturbed seriously by the existence of mesh reinforcement.After the direct signal suppression,removal of the reflec-ted signal and multiple reflections from mesh reinforcement,we can effectively extract the reflected wave signal which is caused by the water bearing structure crack.Our method is applied to real data measured in a tunnel of the Ruchen highway.The re-sults show that after removal of the reflected signal from mesh reinforcement we can accurately determine the location of fissure water,which proves the effectiveness of the proposed method.