STRESS INFLUENCE CHARTS FOR TRANSVERSELY ISOTROPIC ROCKS

A graphical procedure to calculate stresses in a transversely isotropi c halfspace subjected to a three-dimensional surface load has been dev eloped. The surface load can be distributed on an irregularly-shaped a rea. The planes of transverse isotropy are assumed to be parallel to t he horizontal surface of the half-space. The closed-form solutions for stresses at a point under the vertex of a loading sector, with a unit load intensity are presented first. Based on these solutions, five in fluence charts are constructed for calculating the six components of a stress tensor at any given point in the half-space. The charts are co mposed of unit blocks. Each unit block is bounded by two adjacent, rad ii and arcs, and contributes the same level of influence to the stress within the half-space. An example is presented to demonstrate the use of the new graphical method for the case analyzed, results from the n ew graphical method agree with those of analytical solutions within 3% . The new influence charts can be a practical alternative to the exist ing analytical or numerical solutions, and provides results with reaso nable accuracy. (C) 1998 Elsevier Science Ltd.