Failure mechanism of bolting support and high-strength bolt-grouting technology for deep and soft surrounding rock with high stress  

作　　者：李术才 王洪涛 王琦 江贝 王富奇 郭念波 刘文江 任尧喜 

机构地区：[1]Research Center of Geotechnical and Structural Engineering,Shandong University [2]School of Civil Engineering,Shandong Jianzhu University [3]Post-Doctoral Scientific Research Station,Yankuang Group Company Limited [4]Liangjia Coal Mine,Longkou Coal-Electric Company Limited

出　　处：《Journal of Central South University》2016年第2期440-448,共9页中南大学学报（英文版）

基　　金：Projects(51304125,51379114)supported by the National Natural Science Foundation of China;Project(BS2013NJ004)supported by Award Fund for Outstanding Young and Middle-Aged Scientist of Shangdong Province,China;Project(201301004)supported by the Innovation Fund for Postdoctor of Shandong Province,China

摘　　要：In deep underground mining, the surrounding rocks are very soft with high stress. Their deformation and destruction are serious, and frequent failures occur on the bolt support. The failure mechanism of bolt support is proposed to solve these problems. A calculation theory is established on the bond strength of the interface between the anchoring agent and surrounding rocks. An analysis is made on the influence law of different mechanical parameters of surrounding rocks on the interfacial bond strength. Based on the research, a new high-strength bolt-grouting technology is developed and applied on site. Besides, some helpful engineering suggestions and measures are proposed. The research shows that the serious deformation and failure, and the lower bond strength are the major factors causing frequent failures of bolt support. So, the bolt could not give full play to its supporting potential. It is also shown that as the integrity, strength, interface dilatancy and stress of surrounding rocks are improved, the bond strength will increase. So, the anchoring force on surrounding rocks can be effectively improved by employing an anchoring agent with high sand content, mechanical anchoring means, or grouting reinforcement. The new technology has advantages in a high strength, imposing pre-tightening force, and giving full play to the bolt supporting potential. Hence, it can improve the control effect on surrounding rocks. All these could be helpful references for the design of bolt support in deep underground mines.In deep underground mining, the surrounding rocks are very soft with high stress. Their deformation and destruction are serious, and frequent failures occur on the bolt support. The failure mechanism of bolt support is proposed to solve these problems. A calculation theory is established on the bond strength of the interface between the anchoring agent and surrounding rocks. An analysis is made on the influence law of different mechanical parameters of surrounding rocks on the interfacial bond strength. Based on the research, a new high-strength bolt-grouting technology is developed and applied on site. Besides, some helpful engineering suggestions and measures are proposed. The research shows that the serious deformation and failure, and the lower bond strength are the major factors causing frequent failures of bolt support. So, the bolt could not give full play to its supporting potential. It is also shown that as the integrity, strength, interface dilatancy and stress of surrounding rocks are improved, the bond strength will increase. So, the anchoring force on surrounding rocks can be effectively improved by employing an anchoring agent with high sand content, mechanical anchoring means, or grouting reinforcement. The new technology has advantages in a high strength, imposing pre-tightening force, and giving full play to the bolt supporting potential. Hence, it can improve the control effect on surrounding rocks. All these could be helpful references for the design of bolt support in deep underground mines.

关 键 词：high stress soft rock bolting support interface dilation failure mechanism high strength bolt-grouting technology 

分 类 号：TU476[建筑科学—结构工程]