I. Core Principle of High-Efficiency Sediment Discharge from Pneumatic Shield Dams

The biggest advantage of pneumatic shield dams over traditional inflatable rubber dams is their complete collapse, flat base, and absence of any protruding water-blocking structures. Pneumatic shield dams consist of steel shield plates, built-in rubber bladders, and an intelligent control system. When sediment discharge and flood discharge are needed, the bladders rapidly deflate and contract, causing the steel shield plates to completely collapse and lie flat on the concrete base. The overall residual water-blocking height is only 0.8~1.0dm, and the river channel essentially returns to its natural riverbed state. The smooth, flat steel surface, free of wrinkles, bulges, and dead-angle sand accumulation, allows coarse sand, fine silt, rocks, and floating debris to pass smoothly through the river channel without accumulating at the dam site, thus solving the siltation problem at its structural root.

II. Four Core Functions of Pneumatic Shield Dams for Sediment Removal

1. Full Dam Collapse During Flood Season, Achieving Empty Reservoir for Flood and Sediment Discharge
   Before the flood season, the air-shield dam can quickly collapse completely within 5-10 minutes, emptying the reservoir to receive floodwaters. With no obstructions or water-blocking sections, floodwaters carrying large amounts of sediment are discharged smoothly in one go, preventing sediment buildup in front of the dam and river level rise, significantly improving the river's flood control capacity and fully meeting the flood control standards of municipal main waterways.
2. Manual Hydraulic Desilting, Reducing Mechanical Dredging
   During non-flood season water storage operations, when slight siltation occurs, the rapid rise and fall characteristics of the pneumatic shield dam can be utilized to instantly collapse, creating an artificial flood peak. The high-speed water flow generated by the water level difference powerfully flushes away the sediment deposited in front of the dam, achieving automatic hydraulic silt removal, significantly reducing the frequency of manual and mechanical silt removal, and significantly lowering river operation and maintenance costs.
3. Protects the Bladder Structure and Prevents Silt Abrasion and Damage
   Traditional inflatable rubber dam bags are directly exposed to silt erosion, making them highly susceptible to wear, scratches, aging, and damage. In pneumatic shield dams, the bladders are hidden at the bottom of the steel shield plate. Silt, sand, gravel, and floating debris all flow over the steel plate surface, avoiding direct contact with the rubber airbags. This effectively protects core components and significantly extends the equipment's lifespan.
4. The Dam Body Is Less Prone to Siltation and Has Strong Daily Self-cleaning Capabilities
   The surface of the pneumatic shield dam's steel plate is smooth and dense, with extremely low silt adhesion. Daily water flow can easily carry away surface silt, preventing large-scale silt buildup and maintaining long-term unobstructed flow. This makes it suitable for rivers with consistently high sediment content.

    

III. Comparison with Traditional Rubber Dams

Superior Sand Discharge and Compaction Capacity Many engineering projects suffer from severe sand accumulation, primarily due to the selection of the wrong dam type:

• Inflatable Rubber Dams: After collapse, the dam bag becomes soft and bulges, with a noticeable bulge at the tail end and a large residual height. This makes them highly susceptible to trapping sand, rocks, and floating debris, resulting in severe siltation year-round and frequent dredging.
• Pneumatic Shield Dams: Collapses smoothly, without protrusions or dead corners, thoroughly discharging sand, preventing siltation, and not obstructing floods. They are the preferred dam type for high-silt rivers.