BLOCK

Legacy software from 1989 that utilizes block theory has been applied to the planning and design of surface and underground excavations. Source code in FORTRAN and related reports can be downloaded from the earthquake engineering online archive maintained by University of California Berkeley.

BLOCK: BASIC Programs for BLOCK Theory

Shi, Gen-hua; Goodman, Richard E.

Department of Civil Engineering, University of California, Berkeley, 1989,

Block theory has been applied to the planning and design of surface and underground excavations. The object of this technology is to specify the critical joint blocks intersecting an excavation. It applies to rock engineering for for excavations in hard rock where the movement of predefined blocks precipitate failure. A series of Block Theory programs help to find the critical key blocks and possibility of failure in all types of excavations. These were developed along with the theories outlined in the book, "Block Theory and Its Application to Rock Engineering," by Richard E. Goodman and Gen-hua Shi, Prentice-Hall, 1985. The problem is limited in scope--to find the critical blocks created by intersections of discontinuities in a rock mass excavated along defined surfaces. Yet the problem is sufficiently difficult that a series of simplifying assumptions are adopted: (1) All joint surfaces are assumed to be perfectly planar. (2) Joint surfaces will be assumed to extend entirely through the volume of interests, that is, no discontinuities will terminate within the region of a key block. The implications are that all blocks are completely defined by preexisting joint surfaces so that no new cracking is entailed in the analysis of block movements. (3) Blocks defined by the system of joint faces are assumed to be rigid. This means that block deformation and distortion will not be introduced. The key-block problem is formulated entirely through geometry and topology. (4) Discontinuities and the excavation surfaces are assumed to be determined as input parameters. Block theory is developed on the basis of geometric information derived from structural geology and equilibrium calculations using simple statics. It is assumed that continuum mechanics is second in importance to the calculation and description of key blocks. Only block movement modes are to be considered. The suite of programs included in the program package are: (1) General Key Blocks, (2) Stereographic Projections, (3) Stability Analysis, and (4) Tunnels and Shafts.