DRILLING PROCESS MONITORING FOR REFINING AND UPGRADING ROCK MASS QUALITY CLASSIFICATION METHODS

Abstract

A new technique,a new method and a new law were put forward for the refinements and upgrading of current engineering rock mass quality classification methods,i.e. the automatic drilling process monitoring(DPM) technique,the fast and direct time-series analysis of the DPM data and the DPM based findings that the curve of the drill bit advancement depth versus the net drilling time can be easily measured and calculated and that it can be represented as a set of connected linear lines. Each linear line zone has a constant slope gradient or drilling speed and represents an intact and homogeneous rock block. The position of the curve slope gradient jump between any two connected linear zones represents a discontinuity plane. DPM can offer a new measurement method and many factual data for the refinements and upgrading. Consequently,the uniaxial compressive strengths,sizes and spatial locations of rock material blocks and the associated discontinuities in underground can be rapidly,effectively,objectively and quantitatively measured and estimated. Case studies are given to illustrate,explain and describe the new technique,the new method and the new law. The approach and its associated equations were presented to refine and upgrade the current RQD,Q,RMR and BQ methods for rock mass quality classifications. The methods for objectively and effectively measure were included and the rock strength,RQD,rock mass integrity,rock hardness and discontinuities were estimated.