US 12,486,768 B2
Method and system for temporary coating supporting and permanent bolt supporting
Hongpu Kang, Beijing (CN); Pengfei Jiang, Beijing (CN); Ziyue Wang, Beijing (CN); Yongzheng Wu, Beijing (CN); Yaozhong Wei, Beijing (CN); Chang Liu, Beijing (CN); Jichang Guo, Beijing (CN); Chao Luo, Beijing (CN); Xiaoming Cao, Beijing (CN); Zhiliang Chen, Beijing (CN); and Jianwei Yang, Beijing (CN)
Assigned to CCTEG COAL MINING RESEARCH INSTITUTE, Beijing (CN); and TIANDI SCIENCE & TECHNOLOGY CO., LTD, Beijing (CN)
Filed by CCTEG Coal Mining Research Institute, Beijing (CN); and Tiandi Science & Technology Co.,Ltd, Beijing (CN)
Filed on Dec. 6, 2022, as Appl. No. 18/062,095.
Application 18/062,095 is a continuation of application No. PCT/CN2021/121477, filed on Sep. 28, 2021.
Claims priority of application No. 202011044368.X (CN), filed on Sep. 28, 2020; and application No. 202011045647.8 (CN), filed on Sep. 28, 2020.
Prior Publication US 2023/0095265 A1, Mar. 30, 2023
Int. Cl. E21D 11/10 (2006.01); E21D 20/02 (2006.01); E21D 21/00 (2006.01)
CPC E21D 11/10 (2013.01) [E21D 20/02 (2013.01); E21D 21/008 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A method for temporary coating supporting and permanent bolt supporting, wherein tunnel excavation construction operation is composed of a plurality of operation cycle units, and each of the operation cycle units comprises:
excavating by at least one row pitch to form a new tunnel;
spraying a coating material onto a surface of the new tunnel to form a sealing coat on a surface of surrounding rock, wherein within 300 seconds after completion of the spraying, the sealing coat formed by the coating material has a tensile strength of >1 MPa, an adhesive strength of >0.5 MPa, a shear strength of >1 MPa, an elongation of >30%, and a compressive strength of >2 MPa, and the coating material finally has a tensile strength of >3 MPa, a shear strength of >4 MPa, an elongation of >30%, and a compressive strength of >20 MPa;
inserting bolts into the new tunnel to perform permanent supporting; and
wherein each bolt has a grouting channel therein in a length direction thereof; wherein the bolt is provided with a drilling bit at a first end thereof, and the drilling bit is provided with a grout outlet communicated with the grouting channel, the bolt is provided at a second end thereof with a limiting block, a pre-tightening nut, a self-aligning ball gasket and a tray in sequence in a direction from the second end to the first end of the bolt, and the second end of the bolt has a screw thread fitted with the pre-tightening nut, and the limiting block is provided with a grouting through-hole communicated with the grouting channel.