BQS 0317 Estimating Seminar 2 - Calculation Question

1. Excavation to Pit for Pad Foundation and Column Stump
Step 1: Quantity
Pit Size = (0.50mx0.50mx0.50m) x 4 nos
= 0.50 m3
Excavation <1.50m deep = (0.50mx0.50mx0.50m) x 4 nos
= 0.50 m3
Backfill = [(0.50x0.50x0.25)-(0.25x0.25x0.25)] x 4 nos
= 0.19 m3
Allow 10% compaction = 0.19 x1.10
= 0.21 m3
Step 2: Time Required
Excavation <1.50m deep = 0.50 x 3.00 hr
= 1.50 hr
Backfill = 0.21 x 1hr
= 0.21 hr
Total hour = 1.50 + 0.21
= 1.71 hr
Additional 25% time to backfill and excavate = 1.71 x 1.25
2.13 hr
Step 3: Cost
Hourly rate for unskilled worker = RM 40.00 / 8hr
= RM 5.00
Hour required x rate = RM 2.13 x RM 5.00
= RM 10.66
Allow 10% profit and 5% overhead = RM 10.66 x 1.15
= RM 12.26
Step 4: Unit rate
Average cost to excavate 1m3 = RM 12.26 / 0.50 m3
= RM 24.53 /m3