Model investigation of the powerhouse section of a concrete gravity dam

Abstract

1. The presence of ungrouted column joints in buttresses reproduced on models and lightening of the design of the powerhouse section caused a complex character of the distribution of stresses in the structure from the effect of static operating loads. Tensile stresses occurred on the upstream face of the dam within the lower 1/3 of its height. The maximum compressive stresses were observed at lower elevations of the buttresses on the upstream side of vertical column joints, and the occurrence of tensile stresses was noted on the downstream side of these joints. An improvement of the stress state of the structure can be achieved in the case of providing high-quality grouting of the column joints in the buttresses and by making them inclined toward the lower pool. 2. Grouting of the vertical point between the dam and powerhouse had a maximum effect on the stress state only in the immediate vicinity of this joint, i.e., in the toe zone of the dam. The distribution of stresses in the contact zone near the upstream face of the dam, where tensile stresses occurred, and the stress and strain states of the entire structure as a whole after grouting of the indicated joint changed insignificantly. At the same time, investigations of models in the stage of failure showed that the bearing capacity of the structure during interaction of the dam and powerhouse was higher than when the joint between them was not grouted. In connection with this, it is necessary to note that in cases similar to those investigated grouting of the joint between the dam and powerhouse is expedient.