Earthworks at the Inguri hydroelectric station construction site

Abstract

1. At the construction sites of hydraulic structures under mountainous conditions, in canyons with steep walls, the roads leading to the foundation pit should be laid with minimum cuts, they should be constructed on trestles, or they should pass through tunnels on the slopes. In this case it is necessary to lay an optimal number of access roads, which permit a maximum increase of the productivity of earthworks and, subsequently, concrete-placing works. 2. During excavation of the pit it is expedient to construct a concrete support of the finished sections of the pit as the earthmovers descend toward the river channel. 3. During excavation of the underground structures of the Inguri hydrostation the use of highly productive drilling and mucking equipment and heavy-duty vehicles made it possible to increase the degree of mechanization of labor-intensive tunneling processes and to accelerate the construction process. 4. During driving of the diversion tunnel an improvement of the drilling equipment with the introduction of an effective performance scheme of drilling and blasting operation, the use of anchor support instead of a metal arch support, and the use of Be1AZ-540 and KrAZ-265 dump trucks made it possible to achieve a high tunneling rate of the 82-m2 upper level, 90–100 m/month, at faces Nos. 4, 6, and 7 and a record 131 m/month at face No. 10. 5. When excavating the chamber of the hydrostation powerhouse the selection of the optimal scheme of transporting the lossened rock to the surface with the maximum use of all vertical and horizontal accesses promoted simplification and acceleration of the tunneling operations.