Experience in evaluating the quality of consolidation grouting of rocks by seismoacoustic methods at the Inguri hydroelectric station: Fid-Bau Portal

Experience in evaluating the quality of consolidation grouting of rocks by seismoacoustic methods at the Inguri hydroelectric station

Savich, A. I. / Yashchenko, Z. G. / Gorbunov, A. A.

Abstract

Conclusions The regularities and recommendations for seismoacoustic investigations at the Inguri station can be used for checking the quality of grouting of practically any rocks.When evaluating the effect of grouting it is suggested to use the parameter K, which characterizes the degree of grout filling of the primary cavities in rock. As experience at the Inguri station shows, this parameter in comparison with velocity is a more objective and reliable indicator of grouting quality.The value of K, and consequently the effect of grouting within each structural block, change substantially with distance from the tunnel walls. In a section of strong rocks the effect of grouting increases with increase in depth, and in a section of weak rocks it decreases. Furthermore, a difference in the effect of grouting is due to the different initial characteristics of the rocks. Evaluating the results obtained as a whole, we need note the prospects for the proposed and tested method of evaluating the effect of grouting with the use of parameter K. With appropriate planning of the method and volumes of checking investigations we can obtain sufficiently complete information on the effect of grouting on the properties of undisturbed rocks. The results of geophysical determinations should be related to the pressure at which grouting is done and to the volume of grout injected into the rock, which ultimately will permit correcting the grouting process as it is being performed.