Investigation and design of a grooveless gate with a counterpressure chamber

Abstract

Multilevel schemes for the layout of temporary and permanent spillways are presently used in the construction of high-head hydrodevelopments.Such schemes, corresponding to the technical level attained by Soviet gate construction, provides the release of considerable flows over a wide range of heads up to 100-130 m. The number of levels of spillway structures at high-head hydrodevelopments can be reduced by using high-head gates.This can effect a considerable economy, especially in the case of spillway tunnels, since the cost of each level amounts to 10-20 million rubles.At present designs have been developed for deep, mainly vertical-lift and radial gates which can operate satisfactorily under heads to 200 m for opening areas of up to 30 m 2. However, if the temporary discharges during construction are great, the spillway is built with a large number of openings, which adversely affects the hydraulics and leads to an increase in the spillway face, rock excavation, and capital expenditures. Therefore, the need for creating high-head gates covering openings greater than 30 m 2 at heads to 200-300 m is quite pressing.

Design of mechanical equipment for high-head hydroelectric schemes

“…As a result, a turning moment is generated, which tends to rotate the gate and lift its upper supports off the downstream wall [9]. There is then danger of the gate oscillating in the position of unstable equilibrium.…”

“…A balanced gate in an inclined conduit (or inclined shaft) [9] can be used only as the main gate and is located at the downstream end of the conduit. Obviously, the assembly and operating conditions of such a gate in an inclined shaft are considerably more difficult than in a vertical shaft.…”