【摘要】 在煤炭开采和煤层气勘探开发过程以及其他地质工程活动中,现今地应力是一个不可忽略的地质因素。本文收集和估算了中国六个不同含煤盆地1300 m以浅的现今地应力数据,对中国含煤盆地的浅—中深部的地应力特点和地应力分布规律展开研究。研究表明:①东部地区走滑应力场(σ_H>σ_V>σ_h)占比高,向西北地区逐渐降低;中—高应力场占比在中国各含煤盆地差异比较小;②地应力场类型和地应力量级与埋深有关,随着中国含煤盆地开采深度的增加,正常应力场(σ_V>σ_H>σ_h)逐渐占据主导作用,地应力量级也逐渐加大;③通过侧压系数对比,将现今中国含煤盆地浅—中深部地应力强度分为:东北地区高应力区、两淮地区中—高应力区、滇东黔西和沁水盆地中应力区以及鄂尔多斯盆地(东缘)和准噶尔盆地(南部)低应力区;④板块俯冲形成了中国含煤盆地地应力强度东强西弱的分布格局,南北走向的吕梁山是中国北部东西应力强度的分界线;⑤地应力强度向着远离应力源的方向减弱,这种变化规律在中国大陆以及在某个应力分区内(如在沁水盆地和滇东黔西地区)皆有表现。更多还原

【Abstract】 Objectives: In the process of coal mining and coalbed methane exploration and development,Current in-situ stress is a non-negligible geological factor. This paper mainly studies the current in-situ stress characteristics and distribution of coal reservoirs above depth of 1,300 meters in the shallow part of China’s coal-bearing basins.Methods: Based on the current in-situ stress data of 26 coal mines or coalbed methane blocks,the in-situ stress and lateral pressure coefficients of different regions were compared and analyzed. The current in-situ stress characteristics and distribution of different coal-bearing basins were summarized.Results: The study shows that the proportion of strike-slip stress field( σ_H> σ_V> σ_h) in the eastern region is high,and gradually decreases to the northwest regions; The difference of proportion of medium—high stress field in China’s coal-bearing basins is relatively small. The current in-situ stress field and the magnitude of the current insitu stress are related to the buried depth. With the increase of the mining depth of coal-bearing basins in China,the normal stress field( σ_V> σ_H> σ_h) gradually takes the leading role,and the magnitude of the in-situ stress also gradually increases. The current in-situ stress intensity of China’s coal-bearing basins is divided by the comparison of lateral pressure coefficient: the northeast region is a high stress area; the Lianghuai is a medium—high stress area; the Eastern Yunnan—Western Guizhou and the Qinshui basin are medium-stress areas; Ordos Basin( East edge) and Junggar Basin( South) are low stress areas. The subduction of the plate formed the distribution pattern of the current in-situ stress intensity in the coal-bearing basins in China,which is strong in the east and weak in the west. The Luliang Mountain in the north—south direction is the boundary between the east and west stress intensity in northern China. The in-situ stress intensity weakens toward the direction away from the source of force. This change law is significant at Chinese mainland scale as well as at sub-region scale( for example,in the Qinshui Basin and in the Eastern Yunnan—Western Guizhou area).Conclusions: The characteristics of current in-situ stress field in China are different in different coal-bearing basins,and the current in-situ stress intensity shows a distributed law,which is strong in the east and weak in the west. This paper has certain guiding significance for the mining of coal-bearing basins.更多还原