ABSTRACT:

The challenge of obtaining appropriate input parameters remains and may even be growing due to the increased sophistication of the numerical techniques. Indeed, this growing challenge means that increased sophistication is likely to lead to mounting errors of omission and convenience, with the result that modelling confidence and certainty reduces. This paper provides a framework to address these limitations.

1. INTRODUCTION

Numerical modelling of rock engineering problems is now commonplace, with such models being used — and, unfortunately, sometimes abused — on a routine basis. It is well known that the proliferation of numerical tools has been fuelled by increased computer power, user friendly interfaces and improved output graphics. The drive to develop and apply ever more sophisticated modelling techniques, with the aim of increased authenticity and reduced error and uncertainty in the modelling results, seems to continue. Unfortunately, and as this paper shows, the challenge of obtaining appropriate input parameters remains and may even be growing due to the increased sophistication of the numerical techniques. Indeed, this growing challenge means that increased sophistication is likely to lead to mounting errors of omission and convenience, with the result that modelling confidence and certainty reduces. In earlier papers, we have discussed uncertainty and sources of errors in rock engineering [1] and difficulties in geomechanical data collection [2].

2. DATA COLLECTION

Before embarking on any data collection campaign to support numerical analysis, it is critical that we recognize how our understanding of the modelling problem and the availability of data interact. Despite this diagram being first published over two decades ago, the concepts it embodies remain true. The original authors made the point that, as both rock mechanics and rock engineering are essentially data-limited, it is critical to realize that we will generally be working in zones 3 and 4 of this diagram.

This content is only available via PDF.
You can access this article if you purchase or spend a download.