Questions 7 0.1 - 7 0.7 0: anisotropy and inhomogeneity 439
410.5 A vertical site investigation borehole intersects a stratum of sand-
stone which is dipping at 17". A length of intact core from this borehole
was taken to the laboratory for hydraulic conductivity testing, and two
small-diameter plugs drilled from it: one axially and one radially. These
plugs were then tested in a permeameter, and the values of the hydraulic
conductivity were found to be 1.728 x lop7 m/s and 1.557 x IOp6 m/s in
the axial and the radial directions, respectively. Stating any assumptions
that you make, compute estimates of the hydraulic conductivity normal
and parallel to the bedding.
410.6 The diagram shows a polar plot of the variation in hydraulic
conductivity, K, of a sandstone, with the maximal and minimal values
occurring parallel and perpendicular to the bedding.
Why is there a cusp in the (K, 0) locus on the line representing the
direction normal to the bedding?
Parallel to410.7 What does the term 'structural domain' mean in the context of
engineering rock mechanics?
Q 10.8 During a site investigation for quarry development, geometrical
properties of the fractures on a large surface rock exposure were meas-
ured. Eight sampling squares, each 100 m x 100 m, were established on
the rock exposure. One of the set of statistics produced during the site
investigation was the number of fractures with a mean aperture exceed-
ing 10 mm in each sampling square. These results were as follows:
Square: 1 2 3 4 5 6 7 8
461 397 453 362 389 421 382 423