Measurement and analysis of penetration rate and vibration on a roof bolter for identification rock interface of roadway roof

ABSTRACT

At present, Measurement While Drilling (MWD) for detection of the roof rock stratum characteristics is mainly focused on numerical simulation and laboratory research, and the research results are somewhat different from the field experimental results. In order to achieve accurate prediction of the interface position of different rock layers, data acquisition of drilling displacement was performed by Laser displacement sensor in the field experiment. The sinusoidal model of MATLAB is used to fit the displacement, and the penetration rate model and the longitudinal vibration model are established by clustering to analyze the drilling response of different strength rock formations. Finally, the two models established were applied to investigate the position of rock interfaces in a drill hole by clustering. It is revealed that drilling process is cyclical, and the penetration rate processed in the field experiment is consistent with the laboratory and numerical simulation penetration rate. The dynamic response of penetration rate and longitudinal vibration for rock with different strength is an important indicator for identifying rock formations.

KEYWORDS:

• MWD
• roadway roof
• penetration rate model
• longitudinal vibration model
• identification rock interface

Future work

The drilling response model of parameters included penetration rate, rotational speed, vibration and drilled rock thickness and strength are further established to more accurate prediction of rock formation interface locations and different UCS and guide the optimization of roadway support parameters, which ensure the safe and efficient mining.

Nomenclature

MWD	=	measurement while drilling
UCS	=	uniaxial compressive strength
MSE	=	mechanical specific energy

Acknowledgments

Thanks to all co-authors for their help in preparation for this paper. We declare that we do not have any commercial or associative interest that represents a conflict of interest in connection with the work submitted.

Additional information

Funding

This research was funded by the National Natural Science Foundation of China (51574226), the Fundamental Research Funds for the Central Universities (2017CXNL01) and 2017 Special Project of Subject Frontiers Scientific Research in China University of Mining and Technology (2017XKQY047).