地电阻率年变化的方向性与中国大陆构造应力场

本文先研究了矿井中岩体(或矿体)和混凝土胶结充填试件受力作用下地电阻率(s)年变化的方向性.结果表明,平行压力方向的地电阻率年变化幅度最小,垂直压力方向则最大,与压力方向成45夹角的则介于二者之间.根据此结果,我们统计了全国98个地电台的地电阻率资料,并将中国大陆按应力场方向划分为三大应力场区:1.中国西部应力场区,其方向为近南北向;2.中国北部应力场区,其方向为近北东向;3.中国东南部应力场区,其方向为近东西向.因此,可以利用同点三向等极距地电阻率年变化法来测量当时当地不同方向的应力场作用. 

ANNUAL VARIATIONS IN DIRECTION OF EARTH RESISTIVITY AND THE TECTONIC STRESS FIELD IN CONTINENTAL CHINA

This work starts with some measurements of resistivity of rock specimen from mines and of certain concrete underground supports under stress for observing their variations of resistivity with direction. The results show that parallel to the stress, the amplitudes of the annual variations become minimum while maximum perpendicular to it. Halfway between, at an angle of about 45 to the stress direction, the amplitude values of annual variation of resistivity are medium.Based on such a preliminary observation, we used the data of 98 earth resistivity stations scattered all over continental China and divide the entire territory into three stress regions, namely, (1) the West China stress region, with nearly northsouth stress direction; (2) the North China stress region with northeast stress direction; (3) Southeast China stress region with eastwest stress direction. It is thus possible to show the directions of stress field in different parts of the country and at different times by observing in three directions at equal electrode spacings the annual variations of earth resistivity.