Building underground facilities in bedrock is increasing in the modern world. The brokenness and quality of bedrock can have a negative effect on underground construction and effect the costs. One has to be able to describe and measure the brokenness and quality to be able to take it into account in construction and excavation planning. Different mapping methods give direct information and geophysical methods indirect information about the brokenness and quality to support its modeling task. This thesis describes new methods developed to study, visualize and analyze brokenness and quality of the bedrock. The results of the development work were tested on mapping and measurement data gathered from a Palin Granit Oy owned dimension stone quarry situated in Mäntsälä, southern Finland. Observations of the rock discontinuities were gathered by several methods: by mapping and scanline measurements; by ground penetrating radar; and by stereophotogrammetry. The discontinuity data was utilized in developing methods: 1) to calculate fracture density in a rock volume; 2) to write computer scripts, which clusters fracture sets semi-automatically, calculates mean orientation and density of the fracture sets; 3) presents the connection between fracture properties and dip direction; 4) visualizes fractures and their properties in 3D and makes a stereographic projection of the fracture density and rock quality designation revealing their orientation dependency. In addition, development work in the branch of determining fracture filling material based on the polarity change of ground penetrating radar signal was made. The results indicated confidence in determining and modeling the brokenness of the bedrock increases by exploiting several study methods. Gathering abundant observation data enabled statistical analysis of the data and allowed realistic discrete fracture network models to be generated.
|Publication status||Published - 2017|
|MoE publication type||G5 Doctoral dissertation (article)|
- rock fracture, rock quality, fracture density, rock quality designation, scanline survey, oriented data, ground penetrating radar, stereophotogrammetry, MATLAB, Mäntsälä