Arc Gate Plan, Rapid Gate, Inverted Gate, Tunisia

Advantages of Radial Gates

1. Optimal Structural Stress Distribution

The curved shape of the gate leaf (typically a circular arc) allows water pressure to act perpendicularly to the arc surface. This force is efficiently transmitted through radial arms to the hinge shaft (supporting pivot), converting most of the hydrostatic load into axial thrust along the arms rather than bending stress. As a result:

• The gate leaf and arms experience lower structural stress, enabling thinner materials (e.g., steel plates) to be used without compromising strength, reducing overall weight by 15–30% compared to flat gates of the same size.

• The hinge shaft, as the core load-bearing component, distributes forces evenly to the concrete or steel support structure, minimizing foundation reinforcement requirements.

2. Excellent Hydraulic Performance

The smooth, curved profile of the gate leaf aligns with natural water flow lines when partially or fully opened, offering two critical benefits:

• Reduced head loss: The streamlined shape minimizes flow resistance, lowering energy loss by 20–40% compared to flat gates, which is crucial for energy-saving in hydropower or irrigation systems.

• Mitigated flow turbulence: Avoids eddies or cavitation (vapor bubble collapse) near the gate, reducing scouring of downstream riverbeds or channel linings. This is particularly valuable for high-velocity discharge scenarios (e.g., flood release).

3. Low Operating Force and Energy Efficiency

• Water pressure acts close to the hinge shaft, resulting in a smaller moment arm. This reduces the torque needed to rotate the gate, allowing smaller, lower-power hoists (e.g., winches or hydraulic cylinders) to operate even large-span gates.

• Compared to vertical-lift gates (which must overcome friction and full water pressure), radial gates consume 30–50% less energy during operation, lowering long-term operational costs.

4. Easy Maintenance and Accessibility

• Dry maintenance capability: When fully opened, the gate leaf rotates upward and outward, lifting most of its surface out of the water. This allows inspection, repair, or replacement of seals, hinges, and structural components without draining the upstream reservoir—critical for projects requiring continuous water supply or storage.

• Simplified seal replacement: Peripheral seals (rubber or composite) are mounted on the gate leaf’s edge, which is easily accessible when the gate is open, reducing maintenance downtime.

5. Versatility in Large-Span and High-Head Applications

• They can span widths from 5m to over 50m and withstand water heads exceeding 100m, making them ideal for large dams, spillways, or navigation locks.

• Their modular design (e.g., segmented leaves for ultra-wide spans) adapts to irregular or complex channel geometries, unlike rigid flat gates limited by span-to-thickness ratios.

6. Reliable Sealing Performance

The curved gate leaf presses uniformly against the downstream sill and side piers when closed, ensuring tight contact with perimeter seals. This design minimizes leakage (typically ≤0.1L/(m·h) for well-maintained gates), outperforming many other movable gate types (e.g., flap gates with uneven sealing under high pressure).