Variability analysis of rock mass properties using in-situ block size distribution

2001. / by Abera Abebo Hamore - Delft : ITC, 2001. - 109 p. ; 30 cm. - ITC-MSc thesis. ABSTRACT, supervisor(s): Slob, thesis availability: ITC Library

ABSTRACT

Due to several limiting factors, such as time, money, inaccessibility, etc, collecting enough amount of data for characterization of a rock mass is not always possible. Sometimes, such problem may be attacked to a certain extent by using analysis result of variability/homogeneity of their properties.

The main objective of this research is two folds: (i) quantifying the variability of rock mass properties of Lower and Upper Muschelkalk units using In-situ Block Size Distributions (IBSD); (ii) to establish the ratio of sampling use this quantification

The in-situ block sizes for each location have been calculated using the Equation Method, which was developed at QMWC by Wang’s and his co-workers (Wang et al., 1990, 1991; Wang 1992) and updated by new investigation (LU & Latham, 1996; Lu, 1997). The variations of these in-situ block sizes are analyzed by plotting on the charts, using statistical methods, interpolations and visual interpretation.

Statistical analysis result showed that the unit Tg21 (Lower Muschelkalk) is more homogenous than unit Tg23 (Upper Muschelkalk). Moreover, the analysis result for some outcropped areas using interpolation method reveal that the variation of rock mass properties in Tg21 increase from the bottom to the top of following stratigraphic sequence. Where as in the case of the unit Tg23 no clear relation ha s been observed

The ratio of variation between the units Tg21 to Tg23 is less than one to three (1:3), which leads the conclusions that the sampling interval of Tg23 should be three times greater than Tg21.