How do you backfill a pipeline trench?
How do you backfill a pipeline trench?
Fill the lower portion of the trench by depositing approved backfill and bedding material in layers of 6 inches maximum thickness, and compact with suitable tampers to the density of the adjacent soil until there is a cover of not less than 12 inches, using special care not to damage pipe and pipe coatings.
What is the primary purpose of tamping the soil around the pipe while backfilling?
The trench backfill placed on top of the embedment material may also be compacted. Compaction of trench backfill immediately above the pipe facilitates the redistribution of some of the load away from the pipe and into the side-fill soil.
What is the purpose of bedding the excavation?
Bedding and filling materials are used in the sewage and pipeline construction in order to sub- stantially contribute to the structural stability of the underground building and where appropriate to the building on the street, as part of the pipe/ ground structural support system.
How wide does a pipe trench need to be?
For rigid pipes, the maximum trench width at the top of the pipe shall be as follows: • Pipe sizes less than eighteen inches (<18”): Maximum trench width = pipe outside diameter + twenty-four inches (24”) • Pipe sizes eighteen inches (18”) and larger: Maximum trench width = outside diameter + thirty-six inches (36”) If …
When to remove rock from a plumbing trench?
Where rock is encountered in trenching, the rock shall be removed to not less than 3 inches (76 mm) below the installation level of the bottom of the pipe, and the trench shall be backfilled to the installation level of the bottom of the pipe with sand tamped in place so as to provide uniform load-bearing support for the pipe between joints.
What should be done at the bottom of a trench?
If soft materials of poor load-bearing quality are found at the bottom of the trench, stabilization shall be achieved by overexcavating not less than two pipe diameters and backfilling to the installation level of the bottom of the pipe with fine gravel, crushed stone or a concrete foundation.
Why is pipe bedding important when digging a trench?
If the trench width increases, the load that will be carried by the pipe will also increase. Preparation and proper compaction of the pipe bedding is very important. The pipe’s ability to support the overlying earth loads is influenced by the degree of support that the pipe has under it and at its sides.
Why do they use rocks in drainage ditches?
Lining drainage ditches with rocks creates a drainage system called French drains. The rocks are used to allow for greater drawing of water from the source area where the water was pooling.
What kind of rock do you use to backfill a pipe trench?
The ideal material for pipe trench backfill under pavements is crushed limestone with rock ranging from fines all the way up to 2-1/2″.
Lining drainage ditches with rocks creates a drainage system called French drains. The rocks are used to allow for greater drawing of water from the source area where the water was pooling.
If the trench width increases, the load that will be carried by the pipe will also increase. Preparation and proper compaction of the pipe bedding is very important. The pipe’s ability to support the overlying earth loads is influenced by the degree of support that the pipe has under it and at its sides.
How big should a trench be for pipe installation?
Pipe Installation – Trench and Pipe Bedding. As a general rule, trench width should not exceed the pipe diameter plus 60 cm (2 feet). If the trench width increases, the load that will be carried by the pipe will also increase. Bedding Preparation and proper compaction of the pipe bedding is very important.