Backfilling means the process used refilling soil (or) sand an excavated area, backfilling quantity usually calculating in m³ (Cubic meter), basically There are two type of backfilling method used in construction work.
1.Handmade Backfilling – The Soil is refilling by Humans.
2. Machinery made Backfilling – The Soil is refilling machinery.
For Example:–
Size of Footing
Length (L) – 3.00 m,
Width (B) – 2.50 m,
Thickness /Depth (D) -0.75 m
Size of Column
Length (L) – 0.50 m
Width (B) – 0.50 m
Thickness /Depth (D) – 3.00 m
Size of PCC
Length (L) – 3.20 m,
Width (B) – 2.70 m,
Thickness /Depth (D) -0.10 m
So, Volume of Backfilling is,
Formula = Total Volume of Excavation Area – (Total Volume of PCC + Total Volume of Footing + Total Volume of Column) +10% of total Backfilling Quantity
What is 10% – While doing backfilling compaction need 10% of More Soil for backfilling, so 10% of total Quantity need to add in calculation for backfilling quantity.
Volume of Excavation = (3.20 +0.6+0.6) X (2.70+0.6+0.6) X (0.1+0.75+3.0) = 66.07 m³
Total Volume of Excavation = 66.07 m³
Volume of PCC – Length X Width X Depth = 3.20 X 2.70 X 0.10 = 0.864 m³
Volume of Footing – Length X Width X Depth = 3.00 X 2.50 X 0.75 = 5.625 m³
Volume of Column – Length X Width X Depth = 0.50 X 0.50 X 3.00 = 0.75 m³
So, Total Volume of back filling is = (66.70 – (0.864+ 5.625+0.75)) + 10%
= (66.07-7.329) + 10%
= 58.831 + 10% of Total Back Filling Area
= 58.831 + (58.831 X 10%)
= 64.71 m³ Total Quantity of Soil (or) Sand required For Backfilling
So, TOTAL VOLUME OF BACK FILLING IS = 64.71 m³
