基于地震动信号分析的地质灾害过程重构方法研究与应用

RESEARCH AND APPLICATION OF GEOLOGICAL HAZARDS PROCESS RECONSTRUCTION BASED ON SEISMIC SIGNAL ANALYSIS

地质灾害启动及演进过程中对途经的村庄、植被、基础设施等均会造成不同程度的破坏,而深入研究灾害的演进过程有助于灾害预警和防治工作,能减少灾区人员伤亡、降低经济损失。然而由于地质灾害的强破坏性和突发性,使得现场的监测仪器和设备易受灾害的影响,甚至被破坏,导致难以完整且准确地监测到灾害过程,这限制了对地质灾害过程的深入研究,因此亟需一种新的方法来进行灾害过程的重构。随着科技的发展,现有高精度地震仪能够记录伴随地质灾害而产生的地震动信号,并且已有不少研究者进行了基于地震动信号的灾害分析研究。基于现有研究的基础,本文提出一套基于地震动信号的地质灾害重构研究思路和方法体系:通过运用带通滤波器(BP-filter)、经验模态分解(EMD)、快速傅里叶变换(FFT)、短时傅里叶变换(STFT)、功率谱密度计算(PSD)等方法对灾害过程产生的地震动信号进行处理和分析,然后结合灾害现场调查结果进行对比分析以反演灾害的基本特征,进而与数值模拟结果进行耦合,最终实现灾害过程的重构。本文基于地震动信号对堰塞湖、滑坡、泥石流等不同灾种进行案例研究与分析,旨在为地质灾害演进过程的研究提供一种新的研究思路和方法体系。

Geological hazards usually resulted in varying degrees of damage to vegetation and infrastructure.Despite important research efforts such as physical modeling and numerical simulation,the mechanisms that govern the hazard process in a natural environment are still unclear due to a lack of instant on-site monitoring.Nonetheless,on-site monitoring instruments and equipment are still vulnerable to hazards and experienced destruction during the large hazard event,making it difficult for data collection and subsequent validation of numerical models.Therefore,it is urgent to find an effective method to reconstruct the hazards process.With the development of seismology,it is now possible to use the long-period seismic signals recorded by the seismic stations to provide a specific diagnostic of geological hazards.This study explores a set of new methods for the reconstruction of geological hazards based on the seismic signals and subsequent analyzing methods such as Band-Pass filter(BPfilter),Empirical mode decomposition(EMD),fast Fourier transform(FFT),short-time Fourier Transform(STFT),and power spectral density(PSD).The basic dynamic characteristics of geological hazards can then be revealed by comparing and analyzing the field survey results,together with the numerical simulations.Several case studies and analyses of dammed lakes,landslides,debris flows,and other hazards are then illustrated for validating the method.Results suggest the method may be a new way for the fast reconstruction of the evolution process of geological hazards for hazards warning and mitigation.