U-channel irrigation channel construction method

Excavation Work: Due to the smaller cross-section of the U-shaped canal irrigation channel, it is proposed to carry out segmented excavation after the design elevation is sampled. The excavation will be completed in one go, and the trench will be inspected promptly to proceed to the next construction phase. Each construction segment should be approximately 50 meters long.

(2) Cross-section Earthfilling: Due to the elevated installation level of the irrigation channel U-shaped槽 locally being higher than the surrounding fields, additional earthfilling is required for the installation of the canal U-shaped槽. During the earthfilling process, manual transportation of soil and manual tamping will be employed to compact the fill. Initially, a removable steel mold according to the designed earthfilling cross-section will be prepared. After placing the steel mold at the designated elevation on the filling site, soil material will be manually filled into the mold, followed by manual tamping to achieve the required compaction as per the design. Once the design compaction is met, the mold can be removed, and the process can proceed to the next layer of earthfilling.

(3) Sand Layer Reinstatement: After the foundation trench acceptance and the filling of the cross-section, a 5cm sand layer should be reinstated according to the design cross-section. The sand should be evenly spread during the reinstatement, and compacted by lightly tapping with a small tamper.

(4) U-Channel Installation: Once the sand bedding layer at the bottom of the channel is completed, the installation of the U-channel begins. The U-channels are factory-fabricated to the specified dimensions as per the design drawings, with specifications for the top opening size, wall thickness of 4cm, and are manufactured in 1m sections. During installation, manual handling is used with care to prevent damage to the edges. The U-channel seats are placed on the sand bedding layer, ensuring that the bottom elevation of the channel matches the design elevation to meet the design requirements. After verifying the bottom elevation and securing the joints, M10 mortar is used to fill the seams.

(5) U-shaped槽top concrete pouring: After the installation of each work section (50 meters) of the U-channel, the topping concrete pouring can commence. The topping concrete grade is C15. The concrete is mixed uniformly at the batching station and then transported to the site by a mobile dump truck, where it is poured manually. Due to the relatively thin concrete pouring layer of 12cm, it is浇筑 by manual iron troweling and reinforcing rod tamping. The outer surface is then smoothed and compacted manually with an iron trowel to meet the design size requirements.