Hydraulic conductivity in jointed rock masses is primarily governed by the geometrical characteristics of discontinuities, including dip and dip direction, spacing, length, aperture, and the degree of interconnectivity between different discontinuity sets. Although analytical methods based on these geometrical properties are relatively simple, they can still provide reasonable approximations of hydraulic conductivity and help illustrate the influence of each discontinuity set

New Method to Design Reinforced Concrete Lining for Pressure Tunnel/Shaft

There are several traditional, widely used empirical methods for estimating TBM performance, all developed from data recorded in real tunnelling projects. As with any empirical approach, these methods must be applied with care—particularly when geological, geotechnical, or machine conditions differ from those on which the models were originally based. Nevertheless, they can still offer a useful indication of the expected performance range for a selected TBM. In our 2012 paper