小波阈值与小波包对南水北调工程防渗墙监测数据去噪有效性研究

以南水北调北京段大宁水库防渗墙加高施工工程为背景,基于小波包变换去噪法和小波变换阀值去噪法,对现场监测数据进行了消噪处理,比较了两者在工程实际中的应用效果。研究表明,对防渗墙工程安全监测数据,小波包的处理结果更为理想,能够更有效地去除噪音突变信号,保留原始有用信号的突变点,使重构信号能够更光滑地重现原始信号,其去噪法性能比小波变换阀值去噪法更佳,具有更好的实际应用价值。研究结论为后期更加准确地评价防渗墙施工期间的变形和进行墙体长期稳定性分析提供重要依据,研究方法可为类似工程提供参考。

Study on effectivenesses of wavelet threshold and wavelet packet de-noisings for monitoring data of cutoff wall for South-to-North Water Transfer Project

By taking the heightening construction of the cutoff wall for Daning Reservoir for Beijing Section of the South-to-North Water Transfer Project as the background，the de-noising processing is made on the in situ monitoring data with the wavelet packet transform based-de-noising method and the wavelet transform threshold de-noising method，and then the applied effects of both the methods are compared. The study shows that for the safety monitoring data of the cutoff wall，the processing result from the wavelet packet transform based-de-noising method is more ideal，which can more effectively de-noise the abrupt signal of noise，remain the catastrophe points for the original available signals and make the reconstructed signals more smoothly reproduce the original signals.Its de-noising performance is better than that of the wavelet transform threshold de-noising method with a better practical application value. The study conclusion lay an important basis for more accurately evaluating the deformation of the cutoff wall during the construction and analyzing the stability of the wall body for a long period，thus can provide a reference for the similar project.