Important point of corrugated pipe culvert construction inspection project

Base material and backfill materials

1.The base material and backfill materials shall be graded crushed stone or graded gravel , and the size should not be exceeding 3cm, the compaction degree is over 95%, and the reserved arch degree of the foundation is 0.3% -1% of the pipe length.

The wedge-shaped areas on both sides of the steel corrugated pipe culvert should be mainly focused on during backfilling.

2. The wedge-shaped areas on both sides of the steel corrugated pipe culvert should be mainly focused on during backfilling.Use small compacting machinery or manually use wooden sticks to compact diagonally. The point of action of the wooden stick must be tightly attached to the pipe body, and each groove must be compacted in place.

This is an important step related to the quality of the corrugated pipe culvert project. Round the pipe wall about 50cm distance, there should be no stones of size larger than 3cm, to avoice damage to the pipe wall, and avoid decrease in the backfill quality, resulting in the phenomenon of backfill being elevated.

During and after the backfilling process, we can use a small hammer to lightly tap the corrugated pipe wall, and determine whether the backfill is compacted by of the pipe wall.

Layered backfilling

3. When backfilling both sides of the culvert pipe, it is necessary to backfill in layers at the same time, to avoid displacement of the culvert and a decrease in backfill quality.

Construction measures assemble corrugated pipe culverts to prevent cracks in the masonry end wall

4.At present, it has been found that at the construction site of assemble corrugated pipes,some construction companies have not finhsed the top of the pipe assmebly, but have completed the construction of the upstream and downstream retaining walls of the corrugated pipe, This construction method may have the disadvantage of cracks in the wall after filling is completed. Because the corrugated pipe wall may have some deformance during the backfilling process. Normaly the deformance may within 0.5%-2% of the pipe diameter. Of course, this deformation value is closely related to the density of the backfill soil on the pipe side. But when the backfilling is finished, the corrugated pipe culvert will not deformance, and After completion, the impact of vehicle dynamic load on the culvert pipe is also minimal. Therefore, in order to prevent cracks in the end wall, the following two measures can be taken:,

1), After the foundation is completed, the height of the upstream and downstream rubble masonry should be consistent with the top elevation of the gravel foundation. Then, the corrugated pipe can be assembled. After the pipe body is installed in place, the end wall is no need to work on first, and to do the filling of the corrugated pipe,when it is done to the top elevation of the road, After fifteen days, the end wall can be built again.

2), after the corrugated pipe culverts installation is completed, the two side end walls can be built to the same height with the top of culvert pipe, make them at the same elevation. We can use rows of sands and soil bags to block the unconsolidated stoneson the top of corrugated pipe. When the backfilling on the top of culvert pipe has been finished to the same elevation of the max base designing elevation,,15 days later, sands and soil bags can removed , and then build the upstream and downstream end walls.