METHOD FOR CONSTRUCTING A CONCRETE DAM IN A RIVER CANYON

摘要

The invention relates to hydraulic engineering and may be applied in the construction of concrete gravity dams on mountain rivers which flow through narrow canyons. The concrete dam is built in two stages. At the first stage, a reinforced concrete platform 9 is erected above the river, at an elevation sufficient to allow flood waters to pass, and concrete for the upper part 10 of the dam is laid onto said platform. At the second stage, concrete is laid into the lower part 11 of the dam. The first stage is started prior to completion, and the second stage is started after the carrying out, of work related to drilling spillway tunnels, backfilling upstream and downstream cofferdams, diverting the river to the spillway tunnels and draining the foundation trench. The technical result of the invention is a reduction in dam construction lead times due to the earlier commencement of work related to laying of the concrete in the body of the dam. To enable the use of spillway tunnels with a smaller throughput capacity, and thereby reduce capital expenditure in construction of the dam, work related to diverting the river into the spillway tunnels, the laying of concrete in the lower part of the dam and the subsequent sealing off of the spillway tunnels, is carried out in the low streamflow period.