Sensor network optimal design of microseismic monitoring system at the left slope of Jinping I hydropower station

In order to real time monitor and analyze the rock fracturing due to continuous construction and consolidation at the left slope of Jinping I hydropower station, southwest of China, a microseismic monitoring system was conducted and an optimal design for the sensor arrays was investigated. The sensor array was designed on the basis of P method and Powell algorithm. The artificial fixed blasting tests were applied to adjust the positioning accuracy of the monitoring system. The results show that the location error of seismic source is less than 12 m in the scope of the sensor array, which demonstrates the monitoring system has high positioning g accuracy. The contour of source location shows that the location errors near the main tunnels at the left bank slope is below 6 m. Signals from 689 microseismic events with moment magnitude ranging from -2.1 to -0.2 were recorded during the first year monitoring period from June 15, 2009. The spatial distribution of microseismicity can identify and delineate the potential failure at the left bank slope, which provides some references for the future excavation and consolidation of the hydropower station.