关键词: 深部煤矿, 软弱围岩, 三维地应力测量, 流变应力恢复法, 应力解除法

Abstract: In situ stress is one of the most important parameters in underground engineering. In this paper, the basic principles, testing equipment, calculation equations and related procedures of rheological stress recovery (RSR) method are introduced in brief. Then the RSR method, as well as overcoring technique, was carried out to measure the in situ stresses at a depth of 877m in Pingdingshan No. 1 coal mines in Henan Province, China. Three principal stress magnitudes and directions were determined. The maximum and minimum principal stresses are nearly horizontal, and the middle principal stress is nearly vertical. The stress measurement results of RSR method and overcoring technique are basically in the same order, and the major principal stresses are approximately in the direction of NW-SE, which correlates well with the stress regime of Pingdingshan zone known from the tectonic movement history. The application example shows that RSR method is suitable for in situ stress measurement. Especially in complex geology conditions at great depth, conventional methods can hardly be implemented, while RSR method can measure reliable in situ stresses with good adaptability.