Research on deformation and mining-induced stress distribution in surrounding rock of fully mechanized mining face in Wachangping bauxite mine

Wachangping bauxite mine is the first underground non-ferrous metal mine in China that adopts the fully mechanized mining technology. A3D elastoplastic finite element model was used to simulate the stoping process of the fully mechanized mining face, and the deformation of the roof and floor of mining face as well as the spatial distribution and evolution of the mining-induced stress were revealed. The results show that: (1) When the mining face is mined, the roof of mined-out area is subsided and the floor is heaved; the deformation is the largest in the middle of mining face and gradually decreases towards both ends; the longer the length of mining face, the greater the deformation of the roof and floor. (2) The mining-induced stress produces stress concentration at both ends and the front and rear of mining face, forming high supporting pressure areas; at a large range of the roof of mined-out area, the mining-induced stress is reduced and the minimum principal stress is tensile stress nearly vertical. (3) The stress concentration area in front of mining face shifts forward with the advancing of mining face, and the peak value of mining-induced stress gradually increases accordingly; the mining-induced stress of the roof of mined-out area remains relatively stable in the advancing process of mining face. The research results have important guiding roles in the reasonable determination of the length of mining face, the precise support of the mining face roof, the stability control of the stress concentration area, and the safety management of the roof of mined-out area. © 2022, China Science Publishing & Media Ltd. All right reserved.