Applicability Analysis of Microseismic Technology in Tunnel Water Inrush Monitoring

Water inrush disaster is one of the most serious geological disasters in tunnel construction. There are still some problems in the existing researches, such as the activity information of surrounding rock is difficult to obtain, the mechanism of water inrush disaster is unclear, the correlation between water inrush disaster and microseismic (MS) information is missing, which have caused the water inrush disaster to be passively controlled. Combining with the practical experience of tunnel engineering, the application problems of MS technology in tunnel engineering is summarized, which provides ideas for monitoring of surrounding rock activity. The formation mechanism of water inrush disaster caused by rock mass fracturing and filling medium instability has been revealed. The MS characteristics of the water inrush channel in different water inrush disasters have also been revealed. The MS response characteristics of water inrush and rockburst disasters are compared, which provides guidance for the improvement of MS monitoring technology and the analysis of effective MS information. The compression failure test of limestone under saturated and natural conditions is carried out. The results show that the presence of water weakens the ability of rock to store energy. The acoustic emission (AE) phenomenon is weaker in the process of saturated limestone failure, which increases the difficulty of AE monitoring. The number of AE events of natural limestone and saturated limestone shows a slow increase to a sudden increase in the process stress loading, which can be regarded as an important precursor of rock failure.