Abstract
Based on the underground powerhouse of Shuangjiangkou hydropower station,Octree theory is adopted to define the indices of the microseismic(MS)spatial aggregation degree and the deviation values of MS count and energy.The relationship between the MS multiple parameters and surrounding rock mass in-stability is established from three aspects:time,space,and strength.Supplemented by the center fre-quency of the signal evolution characteristics,A fuzzy comprehensive evaluation model and the evolution trend of the MS event center frequency are constructed to quantitatively describe the early warning state of the surrounding rock mass instability.The results show that the multilevel tree structure and voxels generated based on the Octree theory fit relatively well with the set of MS points in three-dimensional space.The fuzzy comprehensive evaluation model based on MS spatial aggregation and MS count and energy deviation values enables three-dimensional visualization of the potential damage area and damage extent of the surrounding rock mass.The warning time and potential damage zone quantified are highly consistent with the characteristics of MS precursors,with wide recognition and field investigation results,which fully validate the rationality and applicability of the proposed method.These findings can provide references for the early warning of surrounding rock mass instability in similar un-derground engineering.
基金项目
Science Foundation for Distinguished Young Scholars of Sichuan Province(2020JDJQ0011)
National Natural Science Foundation of China(42177143)
National Natural Science Foundation of China(51809221)
National Natural Science Foundation of China(52274145)
State Key Laboratory for GeoMechanics and Deep Underground Engineering,China University of Mining&Technology(SKLGDUEK2013)
NETL
NSTL
维普
万方数据