露天转至地下开采岩体响应演化特征研究-江西理工大学

1School of Resources and Environmental Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, China

2School of Civil Engineering, Shaoxing University, Shaoxing 312000, China

3College of Civil Engineering, Qilu Institute of Technology, Jinan 250200, China

4Sinosteel Maanshan General Institute of Mining Research Co. LTD., Maanshan 243000, China

5State Key Laboratory of Safety and Health for Metal Mines, Maanshan 243000, China

Abstract:This study is based on the engineering background of pit no.2 in Jinning Phosphate Mine, China. In order to systematically analyze the movement, deformation, and failure laws of surrounding rocksin underground stopes. The room and pillar method is used to excavate and stop the ore bodies in the mining area. Combined with the similar physical model experiments and discrete element MatDEM numerical simulations, it reveals the deformation and failure laws and evolution characteristics of the surrounding rock of the stope in the process of converting from open-pit to underground mining. The results show the following: (1) Along the inclination of the ore body, the farther the horizontal and vertical displacements are from the underground stope, the less the impact of mining stress. On the other hand, along the inclined vertical direction of the ore body, the farther the measuring point is from the stope, the smaller the range of mining influence will be. (2) In the process of ore body recovery, the rupture of the overlying strata of the stope has an obvious layered structure, with collapse zones, fissure penetrating zones, and microfracture loosen zones appearing from the bottom to top. In addition, the movement and destruction of the overlying strata of the entire stope is an “elliptical arch.” Therefore, the results of similar simulation experiments and numerical simulation are basically consistent.

Fig.4  (a) Similar model; (b) similarity simulation experiment profile.

Fig.5 Displacement survey line monitoring diagram of a similar physical model.

Fig.11 Displacement distribution of excavated rock mass inthe stoping stage.

Fig.13 Comparison of collapse characteristics between numerical simulation and similar simulation under the slope height of 200 m and slope angle of 65°.

Jiabo Geng, Qihang Li, Xiaoshuang Li, Tao Zhou, Zhifang Liu, Yulin Xie, "Research on the Evolution Characteristics of Rock Mass Response from Open-Pit to Underground Mining", Advances in Materials Science and Engineering, vol. 2021, Article ID 3200906, 15 pages, 2021.