Microseismicity and its time–frequency characteristics of the left bank slope at the Jinping first-stage hydropower station during reservoir impoundment
Microseismicity and its time–frequency characteristics of the left bank slope at the Jinping first-stage hydropower station during reservoir impoundment
复制标题
DOI：
10.1007/s12665-016-5539-z
复制
发表时间：
2016-03
影响因子：
2.8
通讯作者：
N. Xu;F. Dai;Zhong Zhou;Pengxiang Jiang;T. Zhao
中科院分区：
文献类型：
--
作者：
N. Xu;F. Dai;Zhong Zhou;Pengxiang Jiang;T. Zhao
为了提高我们对岩质边坡稳定性和岩质边坡-坝复合系统实时行为的理解，在2014年初对2009年5月安装的现有微地震（MS）监测系统进行了改进。本研究是中国首次将这种技术用于评价高岩质边坡的稳定性。通过开发快速准确的实时事件定位技术，以评估地震活动的演变和迁移，并通过开发预测岩质边坡稳定性的能力，研究水库蓄水期间岩质边坡的安全与维护。利用质谱监测系统记录了岩质边坡中大量的质谱事件。通过对蓄水期地震活动的时空分析，确定了受损岩体区域。提出了一种基于S变换的波形分解方法，对左岸边坡施工期和蓄水期的地震波形进行处理，并比较了这两个时期地震事件的时频特征。了解地震信号时频参数变化与岩体损伤之间的关系，可以为评价类似岩质边坡的稳定性提供依据。
The instability risk associated with the left bank slope of the Jinping first-stage hydropower station in south-western China may increase as a result of the initial impoundment of the reservoir and the raising and lowering of the reservoir level. To improve our understanding of the rock slope stability and the real-time behaviour of the composite system of rock slope and dam, an existing microseismic (MS) monitoring system installed on May 2009 was improved in early 2014. This investigation represents the first time such a technique has been used to evaluate the stability of a high rock slope in China. The safety and maintenance of the rock slope during the reservoir impoundment were investigated through the development of fast and accurate real-time event location technique aimed at assessing the evolution and migration of the seismic activity and through the development of capabilities for forecasting the rock slope stability. Numerous MS events in the rock slope have been recorded using the MS monitoring system. Zones of damaged rock mass were identified based on a spatio-temporal analysis of the seismic activity during the impoundment period. Moreover, a waveform decomposition method based on the S transform was proposed for processing the seismic waveforms during the construction and impoundment periods of the left bank slope, and the time–frequency characteristics of seismic events during these two periods were thus compared. The understanding of the relationships between the time–frequency parameters variations in the seismic signals and the rock mass damage can provide a basis for evaluating the stability of similar rock slopes.