Study on geophysical process of strong mining-induced earthquakes and forecast in the short-term and impending stages
LI Tie~(1,2) CAI Mei-feng~1 SUN Li-juan~2 ZUO Yan~2 JI Lin-wang~21.Civil and Environment Engineering School,University of Science & Technology Beijing,Beijing 100083,China;2.Fushun Municipal Seismological Bureau,Fushun 113006,China
Based on field observation of high density digital seismograph and tidal deformation network of meso-scaleseismological experimental site,two strong mining earthquakes in Laohutai coal mine were monitored continuously.The data of strong mining earthquake process is analyzed by seismological methods and wavelet tools,anomalous in-formation on strong mining earthquake is extracted in the short-term and impending stages.By means of focal mecha-nism solution of regional strong earthquake,focal mechanism solution of strong mining earthquake,focus investiga-tion at the nearest field,focus location of high precision,site absolute stress measurement and 3D finite difference nu-merical test,the seismogenic conditions and focal mechanism of strong mining earthquake are analyzed.With the helpof quantitative observation of relativity between mining activity and mining earthquake,analysis is carried out on theinduced factors of mining earthquake.The study points on that the mechanism being of geological structural environ-ment,the stress field and mining activity worked together to induce mining earthquake,and that local stress field playan important role in seismogenic process,that discharged gravitational stress field or coupling of high pressure gasexpand is primary,when induced the mining earthquakes.The consanguineous relativity between mining-inducedearthquakes and gas are found in deep mining,a new kind of mining-induced earthquake induced by coupling of exploi-tation discharge and high pressure gas expand maybe exist.Believable b value,η value,frequency and V_p/V_s ratioseismological anomalies and fixed point tidal deformation anomalies have been extraeted before strong mining earth-quake in the short-term and impending stages.Extraction methods of anomalous information and forecast of strongmining earthquake in the short-term and impending stages are discussed.
【Fund】： 国家自然科学基金(40244021) 辽宁省科学技术计划(2003231003)联合资助
【CateGory Index】： P315
【CateGory Index】： P315