Measurement and Analysis of Jointing Properties in Fine‐grained Soils

Abstract

Jointing can have significant effects on the permeability, shear strength, compressibility, and slope stability of fine‐grained soils. Field measurement of jointing characteristics is an important step in the development of models that simulate fracture flow and directional strength. Preferred joint orientation, which can introduce anisotropy in permeability and strength, can be detected through independent and random measurement of joint orientation combined with graphical or statistical techniques. PATCH, a computer program based on the Poisson statistical test (Mahtab et al.. 1972), was used to evaluate the preferred orientation of joints measured in Wisconsin till units. The program was tested for its ability to reject spurious concentrations of joint poles and calculate mean joint orientation and dispersion. From an analysis of till joint data, we conclude that the use of the statistical computer program alone provided spurious results and required supplementation with other methods to properly determine joint set orientations.