Correct Answer - Option 2 : 10.94 cu. m.
Concept:
Centre Line Method:
- In this method of estimation, the total centerline length of walls in a building is first calculated, then the centerline length is multiplied with the breadth and depth of the respective item to get the total quantity at a time.
- For different sections of walls in a building, the center-line length for each type shall be worked out separately.
- In the case of verandah walls or partition joining with the main wall, the center-line length shall be reduced by half of the breadth of the layer of the main wall that joins with the partition or verandah wall at the same level. A number of such pints arc simnel first to calculate the center-line length.
- By this method, estimates may be prepared more quickly, and this method is as accurate as of the other methods.
- Only in the case of an unsymmetrical wall, which is generally rare, no advantage may be claimed by this method over others as the center-line length varies at every layer.
- But to estimate circular, hexagonal, octagonal, etc. shaped buildings, this method shall especially be adopted.
Calculation:
Given data
Soze of room = 5m x 6m
Wall thickness = 20 cm
The Foundation trench is 60 cm wide and 80 cm deep.
The total length of center-line
= 2 [ (5m + (2 x ( 0.20/2) ) + (6m + (2 x ( 0.20/2) )]
The total length of center-line = 22.8 m
Elements of Building Estimate use Centre-Line Method
| S.N |
Description |
No. |
Length (M) |
Breadth (M) |
Height (M) |
Qty. |
Total |
Unit |
| 1. |
Earthwork in excavation |
1 |
22.8 |
0.60 |
0.80 |
10.944 |
10.944 |
Cu.m |
Hence, the quantity of earthwork in excavation is 10.94 Cu.m.
