Vízügyi Közlemények, 1973 (55. évfolyam)

4. füzet - Rövidebb közlemények és beszámolók

Upstream and downstream of the power station the bed is lined to form the headwater and tailwater aprons. The head- and tailbays are enclosed by retaining walls connected to the powerhouse. The upstream end of the foundation slab at the joint to the upstream apron is connected to an impervious r.c. cutoff wall built by the slurry-trench method. d) The navigation lock The navigation lock on the left-hand side of the weir is displaced upstream relative to the latter. The lock is 125.5 m long and 21.7 m wide with 85 by 12 m clear chamber dimensions. The lock is divided by two expansion joints into three sections of equal length. The voids in the r.c. structure are filled with local material. The sill in the upstream head is at El. 84.0 m A.O.D., whereas that in the downstream head is at El. 78.0 m A.O.D. The top of the structure is at El. 92.00 m A.O.D. (Fig. 2.1—6 and 7). The filling-emptying canals of the lock are in the side walls of the lock chamber. The fish-pass has been accommodated in the right-hand chamber wall of the downstream head. The main closing organs of the lock are mitre gates, while stop-logs serve as emergency closures. The mitre gates and the gates in the emptying-filling ports are operated by oil-hydraulic equipment. The emergency closures are placed by the travelling derrick on the downstream side, an additional derrick of 2X5 ton capacity being provided on the upstream end of the lock. Locking operations are commanded from the control tower situated on the pier at the downstream side. The attendance bays on the upstream and downsteam sides of the lock include the guidewalls, the moorings and the connecting retaining walls. The navigation lock has been constructed with dimensions sufficiently large to meet the specifications for IVth- class waterweys and permits 1350 ton vessels to lock through. The estimated locking capacity is 4.2 million tons per year. e) The flood gate The flood gate situated in the flood plain contributes to the passage of flood wawes occurring every second year on the average (Fig. 2.1—8). This consideration has governed the designs of the structure itself, of the gates and hoisting equipment. The 12 openings of 15 m wide span each are closed by vertical-lift gates, similar structures having been envisaged for providing upstream temporary closure. The gates are hoisted by two gantries of 12.5 capacity each travelling along the structure. Simplicity, reliability of operation and cost considerations alike demonstrated the advantages of the solution adopted. An essential element of the new headrace and tailrace channels is the protection of slopes. Some of the slope surfaces produced by the cut have been retained in the natural condition, while some have been compacted. Rip-rap protection has been placed up to the berm at El. 83.00 m A.O.D. The berm is paved with 80 cm thick rubble on a 20 cm thick base course, while the slope above El. 83.00 m A.O.D. has been protected for the greatest 271