Cement drainage pipes are lifted and placed by cranes with manual assistance. The joints between pipe sections are typically rigid, with expansion joints set every 10 meters. Concrete pouring on the foundation: After the cement drainage pipes are properly placed and checked for accuracy, the upper foundation concrete can be poured. Tunnel construction: Construction of entrance and exit end walls, wing walls, and culvert bottom; attention should be given to structural dimensions during construction.
Pipe Section Transportation and Loading: The quality indicators of the pipe sections to be transported should meet the design and specification requirements. They should be transported to the site by truck and unloaded using cranes. During loading and transportation, caution should be exercised to prevent the pipe sections from rolling and colliding with each other to avoid damage. Concrete Pouring for Foundation: After the bearing capacity of the subgrade foundation reaches the required level, the foundation concrete can be poured. Do not finish the surface smooth when pouring the foundation concrete to facilitate the bonding with the concrete enveloping the pipe section.
Excavation and Treatment of Foundation Pit: Excavate using excavators along the released excavation line to 0.2 meters above the base design elevation. Then, manually clear the base to the design elevation. Subsequently, conduct a base bearing capacity test. If the bearing capacity is insufficient, replace with sand and gravel fill as determined by the probe stress test results, with a width of the foundation width plus 0.5 meters on each side. The replaced sand and gravel fill must be layered and compacted.
Installation of culvert waterproofing layer and repair: Waterproofing layer of cement pipes is laid according to design requirements, along with backfilling of gaps and construction of reinforcement projects. Backfilling: Once the installation of cement drainage pipes is complete, backfilling can be carried out when the masonry mortar or concrete strength of the culvert reaches 75% of the designed strength. During backfilling, it should be done from a range of not less than twice the diameter on both sides of the culvert, and simultaneously, filled symmetrically in horizontal layers according to the design requirements of compaction, ensuring thorough tamping.