微震技术在崩塌落石监测预警应用的研究进展

SEISMIC MONITORING IN ROCKFALL:A LITERATURE REVIEW

崩塌与落石作为岩质边坡破坏与诱发的典型地质灾害,往往具有突发性、隐蔽性和缺乏明显直接的前兆信息,很难做到准确和及时的应急响应,存在巨大的安全隐患。微震技术依靠远程无接触、低成本、广覆盖和24 h高频率无间断监测能力正逐渐被用于崩塌落石的监测预警中。通过监测和分析崩塌落石发生过程的动态振动信号,及时反馈振动信号的发生位置、时间、能量、以及崩塌落石的体积、质量等物理参数,微震技术最终可以做到对崩塌落石发生前的预测预报、发生时的监测预警和发生后的定位抢险。崩塌落石微震监测预警方法应用的难点主要体现在4个方面:(1)崩塌落石信号的识别和分类,通过对微震监测信号的降噪和特征提取,识别崩塌落石信号,并确定灾害发生和结束时刻;(2)崩塌落石的空间定位,确定崩塌落石发生的空间位置;(3)崩塌落石物理参数的反演,通过监测信号反演计算崩塌落石的速度、体积等物理参数;(4)崩塌落石的预警方法,提出崩塌落石预警模型,预测崩塌落石发生时间及地点。本文将从以上4个方面,结合本文作者最新研究成果,讨论微震技术在崩塌落石监测预警应用的最近研究进展,以及目前存在的缺陷。本文可为微震技术在地灾监测预警应用研究提供参考。

Rockfall is characterized by the high occurrence and great destructive damage to people and infrastructure,given the lack of noticeable forerunners and complex mechanisms that are difficult to observe directly and provide early warning precisely.Seismic monitoring offers a unique measurement for studying brittle rock slope hazards.The seismic signals emitted by slope dynamic activities from the surface to the subsurface continuously reflect the dynamic state of the monitoring objective.The seismic signals emitted carry abundant information about the event that generated it and allow researchers to reconstruct the event process.The analysis of seismic signals can provide useful information about the movement onset time within a few milliseconds,the location,the kinetic energy,and the volume of the detached rock mass.There are four research targets faced in seismic monitoring applied in rockfall:(1)Recognizing and classifying the correct signals of rockfall from huge seismic events detected automatically and extracting their seismic features;(2)Locating rockfall events with methods such as arrival times,amplitude-source-location,and polarization;(3)Analyzing the physical features(such as volume,kinetic energy,et al.)of rockfall by fitting a seismic attenuation model and a velocity model;(4)Trying to map the rock slope susceptible area and comply with risk early warning.This article discusses recent progress in the application of microseismic technology in the monitoring and early warning of rockfalls,as well as the current shortcomings and future research directions.This study is a review that provides the state of the art of the application of microseismic technology in rockfall monitoring.