The corrugated steel structure is under the highway, railway and other underground place, it has to have enough bearing strength to meet the load from the top of the structure. As we know, the corrugated steel structure is only one layer of thin steel in corrugation design, how it can meet the big load bearing request, it has to interaction with the filling back soil, so the filling back is so important for the projection quality which is adopted corrugated steel structure. The corrugated steel structure is like a egg shell, if we hold it in our hands and squeeze it, it will not be damage, but if we press the egg shell by finger, it is easy to broken. The corrugated steel structure has same principle as the egg shell.
Filling back request for corrugated steel culvert pipe
The filling back material is well graded natural gravel or break stone.
In the pipe max diameter 50cm outside, use 22T roller, within the pipe max diameter 50 cm, use the small tamp equipment, avoid damage
Back filling should be layer by layer, compact each layer, each layer should be 20cm after compact, every layer should be 95% compact, then can be do the next layer.
The backfill on both sides need to be synchronous, the height difference between two sides can’t be more than 30cm
On the culvert top backfill, the gravel height should bigger than 1m, if the top backfill height is less than 50cm, can’t use the roller bigger than 6T, can’t pass the construction machines too. after reach to the minimum height of backfill, adopt vibratory roller to compact.
Within the 10m scope of the culvert both side,don’t allow to use heavy tamp machine.
For corrugated steel pipe arch, the wedge part is a key part when filling back
The pipe arch is not round shape, so its force points are not uniformly distributed. The wedge part is the force concentration point, when filling back, the wedge part have to be treatment well. On the process of filling back, the force will all come to this part, so if the wedge part is no problem when filling back, then the whole filling back process will be no problem.
The the wedge part, we choose a little harder filling back material, and the material have to surround the entire wedge part of the corrugated steel pipe arch. After compacting this part, then we can start to process next filling back layers.
We have a team special for offer suggestion of filling back for customers
Because the importance of the filling back, my company have a special technical team for suggest and monitor customers filling back after the corrugated steel pipe arch installation. If in China construction site, we will send technical to monitor the filling back process and Timely correction of incorrect behavior by the construction company. If the projection is overseas, we will offer suggestion for filling back to make sure the projection no problem on filling back process.