Inflatable flexible membrane dam (EDPM)

1. Basic Definition

An inflatable rubber dam is a kind of flexible water-retaining structure that relies on filling gas or water into a sealed rubber dam bag to form a certain height of dam body for water regulation. According to the filling medium, it is mainly divided into two categories:

Air-inflated type: This type uses compressed air as the filling medium. It features fast inflation and deflation speed, and is not prone to freezing in winter, so it has been widely applied in cold regions.

Water-inflated type: This type adopts water as the filling medium. It has better stability under the action of water pressure and is more suitable for areas with sufficient water sources and no freezing risk.

The core structure of an inflatable rubber dam consists of three key components:

Dam bag: As the main load-bearing component of the dam, it is made of high-strength synthetic fiber curtains (such as nylon or polyester) as the stress skeleton, with inner and outer layers covered by aging-resistant, wear-resistant and UV-resistant rubber materials (typically EPDM rubber). The size, thickness and strength of the dam bag are customized according to the design parameters such as water retaining height, river width and flow pressure.

Anchoring system: This system is used to fix the dam bag on the dam foundation and abutment walls to prevent displacement or detachment of the dam bag during inflation and water retaining. It is composed of anchor bolts, pressure plates, sealing strips and other accessories. The anchoring points need to be evenly arranged to ensure uniform stress on the dam bag.

Control system: It includes inflation pumps, valves, pressure sensors and control panels, which are responsible for regulating the inflation and deflation processes of the dam bag. The system can realize automatic or manual control, and monitor the internal pressure of the dam bag in real time to ensure safe operation.

2. Working Principle

The operation of an inflatable rubber dam is based on the flexible deformation characteristics of the dam bag and the pressure regulation principle:

Water retaining state: When water retaining is required, the control system starts the inflation pump to fill the dam bag with gas or water. As the filling amount increases, the dam bag expands upward to form a dam body of the designed height, blocking the flow of the river and raising the upstream water level to meet the needs of irrigation, water supply or landscape.

Flood discharge state: When flood discharge is needed, the control system opens the discharge valve to release the gas or water in the dam bag. The dam bag gradually collapses under the action of its own weight and downstream water flow, and the river water can flow through the original dam site smoothly, avoiding the impact of flood on the dam body.

Pressure regulation: During operation, the pressure sensor monitors the internal pressure of the dam bag in real time. The control system adjusts the inflation and deflation speed according to the upstream water level and flow changes to maintain the stable operation of the dam.

3. Application Scenarios

Inflatable rubber dams are widely used in hydraulic engineering due to their flexible and adjustable characteristics, mainly including the following fields:

Flood control and drainage: In flood seasons, the dam can be rapidly deflated to achieve flood discharge, reducing the risk of upstream waterlogging; in dry seasons, it can be inflated to retain water and supplement water sources.

Farmland irrigation: By raising the upstream water level, the dam can divert water to farmland irrigation systems, improving water utilization efficiency and ensuring agricultural water demand.

Urban landscape and water supply: It can be built in urban rivers or lakes to form a stable water surface, beautify the urban environment, and provide domestic water and industrial water for cities.

River regulation and ecological protection: The flexible structure of the dam will not block the migration path of fish and other aquatic organisms, which is conducive to maintaining the ecological balance of the river. Meanwhile, it can also be used to control sediment deposition and improve the river channel.

Temporary cofferdam: In water conservancy construction projects, it can be used as a temporary cofferdam to realize dewatering construction of the construction area, and can be disassembled and reused after the project is completed.

4. Advantages Compared with Traditional Dams

Compared with traditional rigid dams (such as concrete dams and earth-rock dams), inflatable rubber dams have the following obvious advantages:

Low construction cost: The manufacturing cost of the dam bag is lower than that of concrete and steel structures, and the construction process is simple, which can save a lot of manpower and material resources.

Short construction period: The installation of the dam bag can be completed in a short time, and the whole project can be put into use quickly, which is suitable for emergency water control projects.

Flexible operation: It can realize remote control and automatic regulation, and the inflation and deflation can be completed in a short time according to the actual demand, with high response speed.

Strong adaptability: It can adapt to complex terrain conditions such as soft soil foundations, and does not require large-scale excavation and foundation treatment.

Good ecological performance: The flexible structure will not destroy the river ecosystem, and is conducive to the migration of aquatic organisms and the exchange of upstream and downstream water bodies.