^aPully Switzerland

The purpose of this paper is to show how rock mechanics interprets geologic information and helps to adapt engineering design to rock conditions. The paper analyses eight case histories of large engineering projects. In five cases the designers took careful account of the conditions prevailing in the rock masses, the rock characteristics, the strength of the rock and the modified stress—strain pattern created by the new structure. The intrinsic curve of the rock mass, the Coulomb condition, the residual stresses and theE-modulus in the families of joints are among the more important characteristics of the rock mass. In two case histories, it is shown how an erroneous estimate of the cleft-water pressures caused disaster.

Rock mechanics is a necessary link between engineering and geology.