Mechanism and control of spalling for friable sandstone pillars in a room and pillar mine

作     者：Ziwei, Ding Jindui, Jia Amirhossein, Bagherieh Ji, Li Yue, Song 

作者机构：School of Energy Xi'an University of Science and Technology Xi'an710054 China Anhui Province Key Lab. of Mining Response and Disaster Prevention Control in Deep Coal Mine Anhui University of Science and Technology Huainan232001 China Department of Mineral engineering New Mexico Institute of Mining and Technology SocorroNM87801 United States 

出 版 物：《Journal of Engineering Science and Technology Review》 (J. Eng. Sci. Technol. Rev.)

年 卷 期：2018年第11卷第6期

页      面：197-205页

核心收录：

学科分类：0709[理学-地质学] 0819[工学-矿业工程] 070901[理学-矿物学、岩石学、矿床学] 08[工学] 0813[工学-建筑学] 0814[工学-土木工程] 0701[理学-数学] 

基　　金：The study was supported by National Natural Science Foundation of China (Grant Nos.51504183 51874232 51804243) and Natural Science Foundation and Scientific Project Foundation of Shaanxi Province (Grant No.2015JQ5132 17JK0486 2018TD-038), Open Fund of Anhui Province Key Laboratory of Mining Response, Disaster Prevention and Control in Deep Coal Mine (Grant No. KLDCMERDPC13102) 

主　　题：Rock mechanics 

摘      要：The ability to efficiently control sandstone pillar spalling is extremely important in ensuring the safety and highefficiency production of sandstone mines. The increase in size is usually suggested as a remedy for pillar spalling, but none of the suggested remedies reflect the influences of geotechnical properties of rock mass on stability control. Some sandstone mining practices have proven that increasing the size of pillars cannot effectively control pillar spalling. The relationship between the strength of St. Peter sandstone pillar and pillar loads was theoretically analyzed in the current study, in order to examine the influences of geotechnical parameters of sandstone on the stability of pillars and control pillar spalling. The key geotechnical parameters that influence the stability of sandstone pillars were also examined. Subsequently, the pillar instability mechanism and influences of geotechnical parameters on pillar stability were investigated by Finite Difference Method. Finally, a ground control method using shotcrete on pillar was proposed for increasing the stability of pillars. Results demonstrate that compressive stress on the St. Peter sandstone pillar is considerably larger than the compressive strength after mining, resulting in the evident deformation of most regions. The relation curves of displacement at the pillar top with internal friction angle and cohesion are in the power functional distributions, but the change of cohesion is more significant in the pillar strength. The displacement at the pillar top gradually decreases with the increase in internal friction angle, whereas the plastic failure regions of pillars gradually decrease from the bottom to the upper parts with the increase in cohesion. A field industrial test proves that shotcrete on pillars can increase pillar strength, which effectively controls the pillar spalling. Research results provide theoretical and practical guidelines to enhance the stability of pillars under the sa