New Insights of Grouting in Coal Mass: From Small-Scale Experiments to Microstructures

Sustainability

Reza Taherdangkoo¹  Guichen Li²  Yuantian Sun²  Jiandong Huang²  Junfei Zhang³  Junbo Sun⁴ 

[1] Institute of Geotechnics, TU Bergakademie Freiberg, Gustav-Zeuner-Str. 1, 09599 Freiberg, Germany;Key Laboratory of Deep Coal Resource Mining, Ministry of Education of China, School of Mines, China University of Mining and Technology, Xuzhou 221116, China;School of Civil and Transportation Engineering, Hebei University of Technology, Tianjin 300401, China;School of Design and the Built Environment, Curtin University, Perth, WA 6102, Australia;

关键词: pre-grouting;    soft coal mass;    coal-grout structure;    shear behavior;    quality improvement;   

DOI  :  10.3390/su13169315

来源: DOAJ

【 摘 要 】

Pre-grouting as an effective means for improving the stability of roadways can reduce maintenance costs and maintain safety in complex mining conditions. In the Guobei coal mine in China, a cement pre-grouting technique was adopted to enhance the overall strength of soft coal mass and provide sufficient support for the roadway. However, there are very limited studies about the effect of grouting on the overall strength of coal in the laboratory. In this paper, based on the field observation of a coal-grout structure after grouting, a series of direct shear tests were conducted on coal and grouted coal specimens to quantitatively evaluate the quality improvement of grouted coal mass. The results showed that the peak and residual shear strength, cohesion, friction angle and the shear stiffness of grouted coal were significantly improved with the increase of the diameter of grout column. Linear regression models were established for predicting these mechanical parameters. In addition, three failure models associated with coal and grouted coal specimens were revealed. According to microstructure and macroscopic failure performance of specimens, the application of the proposed models and some methods for further improving the stability of grouted coal mass were suggested. The research can provide the basic evaluation and guideline for the parametric design of cement pre-grouting applications in soft coal mass.

【 授权许可】

Unknown