FOREIGN RADIAL

EXPERIENCE GATE

Miklos

A N D TECHNIQUES

WITH VALVE

AND HYDRAULIC

HOIST UDC 627.432.61

Mereni

In 1973 the KiskSros hydraulic development (Fig. 1), which includes a five-bay spillway, a 12 x 85-m navigation lock, and a 24-MW hydroelectric plant was placed in operation on the Tisza River, in the Hungarian plains. The m a i n purpose of this hydraulic development is to store 400 9l 0 s m s of water and to ensure its supply to an irrigation system being constructed. The spillway bays have gates equipped with valves (Fig. 2) for close con=ol o f the prescribed water levels. Radial gates are used for closing off large openings. For their fabrication, 15~ less steel is required in comparison with other types of gates. Also, they are noted for their operating reliability and relatively small values of the lifting force. The spillway gates at the Kisk~ros hydraulic development are among the most modern and largest of their type. These gates cover spillway bays 24 m wide and 11.3 m high and transmit a water pressure of 1500 tons. The spillway bays are separated by 3.6-m-wide piers (instead of the 6 - 7 - m - w i d e piers which would have

Fig. I. General view of hydraulic development. Translated from Gidrotekhnicheskoe Stroitel'stvo. No. 7, pp. 51-55. July. 1976.

723

724

MIKLOS MERENI

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i Fig. 2. Radial gate with valve and hydraulic hoist. been required in the spillway for other types of gates). The hydraulic hoists are installed on the piers and the oil pumping plant, the control units, and other equipment are installed in compartments located in the upper part of the piers (Fig. 3). The l a t e r a l faces o f the piers are smooth (with the exception of the grooves for the upstream stoplogs); this is permitted by the construction of the radial gate and of the bridge-type downstream smplogs. This type of equipment provides a means for increasing the discharge capacity of the spillway by 5% and for simplifying its construction. At the closure place, on the floor, there is a 3 . 2 - m - h i g h streamlined s i l l which m a d e it possible to reduce the gate height m 11.3 m (instead of 14.5 m). The local narrowing of the streamlined elements causes the water level to rise only 2-3 era. The gate span is built in the form of a rigid trapezoidal beam resting on the segment legs. The design v a l ue of the span is 23 m . The center of the arc of the gate skin plate, which is 14 m in radius, is located at a distance o f 1.0 m above the point of rotation; this reduces the required lifting force considerably. However, the lateral seals of the segment, as well as the embedded parts, are fabricated with the radius described from the gate rotation center. The segment legs are A-shaped with closed sections, and have Vierendeel-type tapered bearings. The bearing (Fig. 4) is m a d e from east st~eel and has a cantilevered-projecting cylindrical shaft. The casting is secured to an embedded welded tube which serves to redistribute the load from the shaft to the pier or abutm e n t . The shaft has a bronze hub with a spherical surface. Self-adjusting bushings permit the bearing to rotate in the plane of the radial gate p o r t a l

RADIAL G A T E

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Fig. 3. Location of hydraulic hoists, feeding units, and oil pipes in abutment (longitudinal and transverseseetions), l) Hydraulic hoist; 2) rods for measuring the traveled distance; 3) electrosignalingof rod position;4) segmental pin (axis of rotation); 5) segment leg; 6) concrete-enveloped hanging element of hydraulic hoist; 7) feed unit and oii tank for segment; 8) feed unit and oil tank for valve; 9) oil pipe for segment; 10) oiIpipe for valve; 11) valve position indicator; 12) reinforced-concrete support for craneway.

Fig. 4. Radial gate bearing. The extreme diaphragms of the segment consist of curtains which rest on the segment legs (Fig. 5). Between the curtains there is a 22.5-m long valve which transmits the load to the gate span through two hinges, and a servomotor located at the middle of the span. The valve is subjected to torsion and bending. The radius of curvature of the skin plate, which is strengthened by stiffeners, is 8 m, and the radius of the bearing beam of the valve is 1.1 m. Aeration of the water layer overflowing through the valve is ensured by supply of air through holes made in the curtains.

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MIKLOS MERENI

Fig. 5. General view of blind and radial gate leg (factory assembly).

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Fig. 6. Seals (the arrows indicate the flow direction), a) Horizontal seal between segment and valve; b) v e r ~ c a l seal between valve and curtain; c) lower horizontal seal of segment; d) v e r t i c a l seal between segment and embedded part. Between the valve and the segment, along the horizontal, there is a sheet rubber seal (Fig. 6a), and between the valve and the curtains (Fig. 6b) as we]/as between the segment and the concrete-enveloped arched elements of the embedded parts there is a special rubber seal having an open angular s h a p e ( F i g . 6d). The lower horizontal seal of the segment, which is of the knife type, is shown in Fig. 6e. The v e r t i c a l embedded parts are electrically heated. However, only a 100 x 6-ram stainless steel strip directly in contact with the seal is heated. This strip is cemented to the embedded steel parts by means of " A r a l dit," a special glue which is also an insulating material. Voltage from a special transformer is applied to heat the strip. The speei~c heating power is 0.3-0.5 kW/m. The segment span is equipped with two lateral wheels, one installed on each side. T h e wheels are designed for a force of 8 tons and can reverse direction, thanks to a buffer mechanism. The hydraulic hoists and the oil pumping plant, for a working oil pressure of 160 aun, were supplied by the ~rm "Erster Gidraulik" o f the German Democratic Republic.

RADIAL GATE

727

Fig. 7. General view of upstream stoplogs.

Fig. 8. General view of downstream stoplogs. Each of the two hydraulic hoists for the radial gate, which operate in synchronism, has one end hinged to the segment leg, ~nd the other suspended from a special plate instaUed on the pier. The hydraulic hoist rods are 500 mm in diameter and operate independently of each other; however, for a rod travel distance of 5000 mm. electroautomation ensures synchronima within 1Lrnits o f 20 m m .

728

MIKLOS MERENI

Ioining of the hydraulic hoist at one third of the length of the leg from the supporting hinge results in an increase in the value of the lifting force; nevertheless, this disadvantage is compensated for by a relatively small travel of the hoist rod (5000 m m ) . The maximum pull produced in each hoist during opening of the gate is 255 tons, the maximum during closure is 185 tons. The oil pumping plants which serve the radial gate are symmetrically located in the bay, in mirror r e f l e c tion. The 1600-liter tank in each oil pumping plant is sufficient to supply all the oil required for the hydraulic c y c l e . T h e hoist rod speed both during lifting and lowering of the gate is 8.4 c m / m i n (4- 15 %). In the closed position, the m a x i m u m allowable descent rate of the hoist rod does not exceed 2 m m / h and when the descent reaches 20 m m the rod automatically returns to the starting position. Precise control o f the upstream level is performed by a valve operated by a 400-mm diameter hydraulic hoist with a travel of 2100 m m . T h e oil pumping plant for the valve hoist is located in a left-side compartment in each bay, together with the oil pumping plant for the hydraulic hoist serving the left part of the radial gate. The oil lines for the valve hoist pass through the l e f t - s i d e point of rotation of the gate. Local and centralized control of the gates is provided for. Local control serves mainly for testing and adjustments during erection, revision, and repairs. For better vision, the central control panel is located in the upper floor of the control building, which was constructed on the right bank. Ordinary power supply is used; however, for greater reliability, two independent transmission lines located on both banks are employed as power sources. All signaling, measuring, and starting elements located on the central panel are divided into five units, corresponding to the five bays. A sixth, special unit is intended for selective operation of the gates and for simultaneeus openings of aU five bays. T h e instruments and devices on the central panel perform the following operations: selection of the operating regime of the equipment; selection o f the units which i t is desirable to switch to centralized control; reception o f symbol and coded signaling from instruments installed in the hydraulic hoists for measuring the traveled distanee; signaling of the position of the radial gates when moving in synchronism; automatic disconnection in case of emergency; indication of working oil pressure in all oil pumping plants; in addition, the panel has keys and buttons for different operations, as well as light and sound signaling for emergencies. The radial gates and their embedded parts can be revised and repaired under the protection of downstream and upstream stoplogs. The upstream stoplogs consist of five wheeled v e r t i c a l - l i f t sections (Fig. 7) which are installed in the bay by means of a grab beam and the two spillway gantry cranes, each with a 40-ton lifting c a pacity. Each section weights 52 tons and has four wheels, a span structure in the form of a trapezoidal beam, and a skin plate on the downstream side. If required, the stoplogr can be installed in the flow, but only when the difference between the levels does not exceed 3 m . To reduce the harmful effects of vertical and hydrodynamic forces occurring when the sections are lowered in the flow, the trapezoidal beam is of the through type. The welded structure of each seer.ion consists of three bolted components. The downstream stoplogs are of the bridge type and consist of a bridge beam (Fig. 8) and 12 needles 8 m high and 2 m wide, which are installed by a gantry crane on the d a m . Divers are not required for their installation. The bridge beam rests on the lateral faces of the piers and abutments. The needles are secured to the bridge beam at their top and rest on special concrete steps on the sill at their bottom. The spillway gates and steel elements of the navigation lock at the Kisk~ros hydraulic development, with a total weight o f about 8000 tons, were sandblasted and covered first with a '/0-/~-thiek zinc coating and then with a 100-fl-thiek aluminum spray coating. This made it possible to obtain a protective m e t a l covering, on which four coatings (200-250 fl) of bituminous paint with epoxy resin were applied. The effectiveness of this protection is guaranteed for seven years. Corrosion resistance of the valve's internal surface is ensured by waterproof construction. Integrated use of modern progressive solutions for the m e c h a n i c a l equipment and the structures permitted obtaining reliable and easily operated gates meeting the requirements placed on them.