Air - shield Dam Manufacturers Discuss Issues Needing Attention in the Design of Rubber Dam Projects

Air - shield dams play a good role in ecological protection, and the same goes for rubber dams. Have you ever heard of rubber dams? Today, air - shield dam manufacturers will briefly discuss the issues needing attention regarding rubber dams. Let's quickly find out together!

What aspects should be noted in the design of the civil engineering of rubber dams? Air - shield dam manufacturers will introduce them in detail.

The selection of the elevation of the foundation floor of a rubber dam is not only directly related to the dam height, the perimeter of the dam bag, and the project cost, but also closely related to the operational requirements and the maintenance of the dam bag. If the elevation of the dam floor is set lower, the discharge capacity can be increased, but the height of the dam bag will increase, the perimeter of the dam bag will be correspondingly lengthened, and the maintenance conditions of the dam bag will be poor. Therefore, without affecting the discharge, especially on rivers in mountainous areas of our province where the bed load is relatively serious, it is more beneficial to set the floor slightly higher than the riverbed. The elevation of the dam floor is appropriately raised by 0.2m - 0.4m compared to the average elevation of the upstream riverbed topography. This can not only reduce the overall project cost, improve the maintenance conditions, and facilitate observation, but also prevent the bed - load sediment passing through the dam from being rolled into the bottom of the dam bag along with the water flow, thereby reducing the wear of the dam bag.

To prevent the formation of local vacuum and negative pressure under the water jet and enable the gravel passing through the dam to be smoothly discharged downstream, a slope section is commonly used to connect the stilling basin and the floor. The slope of the slope section is not clearly defined in the "Code", but it is mentioned in the "Explanation of the Code Provisions" to be 1:2 - 1:4, and it is clearly stated in the "Technical Guide for Rubber Dam Projects" (hereinafter referred to as the "Guide") that it should not be steeper than 1:3. Generally, 1:4 or a larger slope is adopted, which should be determined according to the water flow pattern. The author believes that a gentler slope is better because the steep slope section is adjacent to the end of the floor. If the water flow pattern at this section is not good, it will affect the end of the dam bag after the dam collapses, causing vibration and wear, and shortening the lifespan of the dam bag.

The specific length of the intermediate pier is not clearly defined in the "Code", but the "Guide" states that "the length of the intermediate pier should be greater than the length of the dam bag in the working state, but it is advisable to be less than the length of the floor by 0.5m - 1.0m." The author believes that the length of the intermediate pier should be not less than 0.5m - 1.0m of the length of the floor, mainly considering the maintenance passage requirement on the downstream side of the floor. However, for safety reasons, the author believes that the downstream side of the intermediate pier should be about 0.5m longer than the end of the dam bag after it collapses. Because if the intermediate pier is too short and the dam bag extends beyond the downstream side of the intermediate pier, when there is a large flood, the water flow will form a backflow and vortex on the downstream side of the intermediate pier, causing severe vibration and slapping of the dam bag, resulting in serious wear of the dam bag. There was once a similar incident in a rubber dam, which led to the dam bag being worn through.

The above are the precautions in the engineering design of rubber dams introduced by air - shield dam manufacturers. I hope it will be helpful to you.