Improved filtering and normalizing of Measurement-While-Drilling (MWD) data in tunnel excavation
Jeroen van Eldert, Håkan Schunnesson, David Saiang, Johan Funehag
Abstract
Measurement-While-Drilling (MWD) data are complex because of the drilling process and drilling system. Swift and accurate normalization and filtration processes are required if MWD data are to be used for rock mass characterization. The current method for MWD data filtration does not consider all the effects of the drilling process, e.g., collaring or extension rod coupling. This paper presents a new method for MWD data filtration and normalization. The new method filters the operational parameters and normalizes the data on a stepwise algorithm, including production factors (collaring drill hole and rod extension coupling) and rock drill settings. It shows reliable results for the normalization and filtration of MWD data gathered for drill hole collaring and coupled extension drill rods at grout holes and for different rock drills.