Study on stress evolution law and rock burst mechanism in upright fold structure area of deep mine

Abstract

With the increase in coal mining depth, many rock bursts triggered by fold structures have been observed, but the disaster mechanism is not clear. This research aims at investigating the influence of upright fold structure(UFS) on rock burst mechanisms. The mechanical model and numerical model of the UFS are constructed, and the mining stress evolution law and rock burst mechanism of working face in a UFS area are studied by utilizing engineering practice. The research shows that the occurrence of rock burst disasters in the fold structure area has obvious regional characteristics. The horizontal and vertical stress of the UFS in the horizontal distribution is similar to the periodic variation characteristics of the sine (cosine) curve. The stress state of the UFS area is divided into five areas. The horizontal and vertical stress concentration factors increase first and then decrease with the working face gradually approaching and away from the upright fold syncline axis. A roadway impact risk index I 0 is proposed to determine whether the roadway is damaged, and the mechanism of inducing ground pressure during mining in UFS areas of deep mines is expounded. The control plan effectively reduces the stress levels of surrounding rock in working faces.