I. Design Module
Adopting a modular design concept, the air shield dam divides the dam body into three independent units. All components are prefabricated and inspected in the factory, requiring only on-site assembly for final completion. The specific components are as follows:
Steel Shield Plate: Made of high-strength weather-resistant steel, formed through CNC cutting and automatic welding, and treated with thermal spraying anti-corrosion technology on the surface. It mainly undertakes the tasks of water retaining and bearing water pressure.
Inflatable Air Bag: Manufactured with multi-layer rubber composite materials, it features excellent air tightness and anti-aging performance, and provides power for the lifting and lowering of the dam body through air inflation and deflation.
Intelligent Control System: Integrated with water level sensors, pressure transmitters and PLC programmable logic controllers, it realizes remote automatic adjustment of dam height and closed-loop water level control.
This design mode of "factory manufacturing and on-site assembly" ensures the processing accuracy and consistency of all components, greatly reduces on-site concrete pouring and welding work, and creates favorable conditions for efficient subsequent installation.
II. Installation Module
On-site installation follows standardized streamlined operations, which are carried out in the following steps:
1. Civil Foundation Construction
Complete foundation pit excavation, foundation bearing capacity detection, cushion laying and reinforced concrete bottom plate pouring. Meanwhile, anchor bolts and air pipeline casings are accurately embedded to ensure that the flatness error of the bottom plate is within the allowable specification range.
2. Dam Body Equipment Installation
Operate in the sequence of setting out and positioning, shield plate hoisting and positioning, anchoring connection, air bag laying and pipeline connection. The mechanical assembly of a single dam section can usually be completed within several days.
3. Electromechanical System Integration and Commissioning
Install the control cabinet, arrange sensor circuits and connect pneumatic pipelines, and then conduct graded inflation commissioning. Maintain pressure for 30 minutes at each pressure level, and comprehensively inspect the dam body tightness, flexibility of shield plate turnover and response speed of the automatic control system until the designed water retaining height and discharge capacity are achieved.
III. Installation Cycle
The total construction period of air shield dams varies significantly with project scale. The reference cycles for different types of projects are listed below:
Small-scale projects (dam length ＜ 30 meters, such as landscape dams and small irrigation dams): 15～30 days;
Medium-scale projects (dam length 30～100 meters, such as river regulation and urban flood control projects): 1～3 months;
Large-scale projects (dam length ＞ 100 meters, such as large reservoir reinforcement and watershed control projects): 3～10 months.
It is worth noting that civil foundation construction generally accounts for 60%～70% of the total construction period, while equipment installation and commissioning are relatively efficient and serve as the key factor affecting the overall progress.
Practical engineering cases verify the above cycle rules:
A medium-scale river regulation project in Linyi, Shandong Province (80-meter dam length) was originally scheduled for a 3-month construction period. Benefiting from modular design and timely supply of prefabricated components, on-site installation and commissioning were completed in less than one month, bringing engineering benefits ahead of schedule.
A small urban landscape dam (20-meter dam length) was fully completed and delivered for use within 28 days from foundation excavation to final acceptance.
A large reservoir reinforcement project (120-meter dam length) took 9 months in total due to the treatment of complex deep overburden foundation, which is in line with the construction period expectation for large-scale projects.
The above cases prove that with a highly integrated design concept and efficient installation procedures, air shield dams can flexibly adapt to construction demands of various scales. While ensuring engineering quality, they effectively shorten the construction cycle, making them a preferred dam type with excellent functionality and timeliness in current water conservancy projects.
