Methods of Backfilling & Plinth Filling
Backfilling is the process of filling the excavated Plinth or trenches after the construction of footing. Plinth filling is done to fill the area within the Plinth. The excavated material from the Plinth or the material procure from the outside is used for this.
This video shows the method of Back and Plinth filling to attain the maximum compaction.
The material for filling shall be free from lumps, Roots, Vegetation, Harmful Salts/Chemicals and organics Materials etc. The Plinth or trenches to be Backfill shall be cleared of all the shoring and formwork material or trench of any salt. The entire space between the substructure i.e foundation and side of excavation shall be filled back to the original surface level in layer not exceeding 250 mm in thickness. It shall be watered and well compacted by means the ramers to achieve maximum consolidation. For Plinth filling it shall start from the lowest level in the horizontal layer not exceeding 250 mm in depth. Each layer should be compacted by ramming with rammer of 7-10 Kg weight. Filling shall be adequately watered and ramped for achieving maximum compaction.
Backfilling & Plinth Filling Summary & Process:
Backfilling shall be done after the foundation has completely set.
Backfilling shall be carried out in layer and each layer shall be thoroughly compacted.
Inadequate compaction is likely to cause settlement of backfilling resulting in development of cracks in flooring.
Mechanical rammers are referable to hand rammers. Use hand rammers where area is inaccessible to mechanical rammers.