How to Calculate the Long wall - Short Wall Method of Building Estimation |Estimating By Long wall - Short Wall Method|long wall short wall method|lon
long wall short wall method | long wall and short wall method | long wall short wall method of estimation problems pdf
INTRODUCTION :
Longwall - Short Wall Method:
Calculation:
Procedure:
First, we have to calculate, the out-to-out length of the longwall & in to in length of the short wall above the plinth level.
Out to out longwall = [room length + (2nos. × wall thickness)]
= [5m. + (2nos. × 0.3m.)]
= 5.60m.
In to in short wall = room width
= 3.5m.
Now,
Length of longwall of a particular item
= [out to out longwall + (2 × one side offset)]
Length of the short wall of a particular item
= [ in to in short wall - (2 × one side offset)]
Where one side offset or half offset
= [(breadth of the item - wall thickness above plinth) ÷ 2]
1. calculation of Excavation for foundation:
One side offset = [(breadth of the item - wall thickness above plinth) ÷ 2]
= [(1.20m. - 0.3m.) ÷ 2]
= 0.45m.
Length of longwall of excavation
= [out to out longwall + (2 × one side offset)]
= [ 5.60m. + (2 × 0.45m.)]
= 6.50m.
Length of short wall of excavation
=[ in to in short wall - (2 × one side offset)]
= [ 3.5m. - (2 × 0.45m.)]
= 2.6m.
Excavation volume at longwall
= 2nos. × [longwall length × breadth × depth]
= 2nos. × [ 6.5m. × 1.20m. × 0.7m.]
= 2nos. × [ 5.46 cum.] = 10.92 cum.
Excavation volume at short wall
= 2nos. × [short wall length × breadth × depth]
= 2nos. × [ 2.6m. × 1.20m. × 0.7m.]
= 2nos. × [ 2.184 cum.] = 4.368 cum.
The total volume of the excavation
= [volume at long wall + volume at short wall]
= [10.92 cum. + 4.368 cum.]
= 15.288 cum.
2. PCC in foundation:
Length of longwall of PCC = length of longwall of excavation = 6.5m.
Length of short wall of PCC = length of short of excavation = 2.6m.
PCC volume at longwall
= 2nos. × [longwall length × breadth × thickness]
= 2nos. × [ 6.5m. × 1.20m. × 0.15m.]
= 2nos. × [ 1.17 cum.] = 2.34 cum.
PCC volume at short wall
= 2nos. × [short wall length × breadth × thickness]
= 2nos. × [ 2.6m. × 1.20m. × 0.15m.]
= 2nos. × [ 0.468 cum.] = 0.936 cum.
The total volume of the foundation PCC
= [volume at long wall + volume at short wall]
= [2.34 cum. + 0.936 cum.]
= 3.276 cum.
3. Foundation:
One side offset = [(breadth of the item - wall thickness above plinth) ÷ 2]
= [(0.9m. - 0.3m.) ÷ 2]
= 0.3m.
Length of longwall of foundation
= [out to out longwall + (2 × one side offset)]
= [ 5.60m. + (2 × 0.3m.)]
= 6.20m.
Length of short wall of foundation
=[ in to in short wall - (2 × one side offset)]
= [ 3.5m. - (2 × 0.3m.)]
= 2.9m.
Foundation volume at longwall
= 2nos. × [longwall length × breadth × depth]
= 2nos. × [ 6.2m. × 0.9m. × 0.55m.]
= 2nos. × [ 3.069 cum.] = 6.138 cum.
Foundation volume at short wall
= 2nos. × [short wall length × breadth × depth]
= 2nos. × [ 2.9m. × 0.9m. × 0.55m.]
= 2nos. × [ 1.436 cum.] = 2.871 cum.
The total volume of the foundation
= [volume at longwall + volume at short wall]
= [6.138 cum. + 2.871 cum.]
= 9.009 cum.
4. Plinth wall:
One side offset = [(breadth of the item - wall thickness above plinth) ÷ 2]
= [(0.6m. - 0.3m.) ÷ 2]
= 0.15m.
Length of longwall of plinth
= [out to out longwall + (2 × one side offset)]
= [ 5.60m. + (2 × 0.15m.)]
= 5.9m.
Length of short wall of plinth
=[ in to in short wall - (2 × one side offset)]
= [ 3.5m. - (2 × 0.15m.)]
= 3.2m.
Plinth volume at longwall
= 2nos. × [longwall length × breadth × depth]
= 2nos. × [ 5.9m. × 0.6m. × 0.45m.]
= 2nos. × [ 1.593 cum.] = 3.186 cum.
Plinth volume at short wall
= 2nos. × [short wall length × breadth × depth]
= 2nos. × [ 3.2m. × 0.6m. × 0.45m.]
= 2nos. × [ 0.864 cum.] = 1.728 cum.
The total volume of the plinth
= [volume at long wall + volume at short wall]
= [3.186 cum. + 1.728 cum.]
= 4.914 cum.
5. Room wall:
As there is no offset for room wall
Longwall length = out to out longwall length = 5.6m.
Short wall-length = in to in short wall-length = 3.5m.
Room volume at longwall
= 2nos. × [longwall length × breadth × height]
= 2nos. × [ 5.6m. × 0.3m. × 3m.]
= 2nos. × [ 5.04 cum.] = 10.08 cum.
Room volume at short wall
= 2nos. × [short wall length × breadth × height]
= 2nos. × [ 3.5m. × 0.3m. × 3m.]
= 2nos. × [ 3.15 cum.] = 6.30 cum.
The total volume of the room wall
= [volume at long wall + volume at short wall]
= [10.08 cum. + 6.30 cum.]
= 16.38 cum.
Note: The estimation is done in an elaborate way so that you will understand the concept clearly. Actually, the estimation is done in a table format as shown below.
Sl. No. | Description | Nos. | Length in m. | Breadth in m. | Depth in m. | Qty. in cum | Total Qty. in cum. |
1. | Excavation for foundation.
|
| |||||
1a. | Long wall | 2 | 6.5 | 1.2 | 0.7 | 5.46 | 10.92 |
1b. | Short wall | 2 | 2.6 | 1.2 | 0.7 | 2.184 | 4.368 |
| Total volume of excavation | 15.288 | |||||
2. | PCC for foundation. |
| |||||
2a. | Long wall | 2 | 6.5 | 1.2 | 0.15 | 1.17 | 2.34 |
2b. | Short wall | 2 | 2.6 | 1.2 | 0.15 | 0.468 | 0.936 |
| Total volume of foundation PCC | 3.276 | |||||
3. | Foundation |
| |||||
3a. | Long wall | 2 | 6.2 | 0.9 | 0.55 | 3.069 | 6.138 |
3b. | Short wall | 2 | 2.9 | 0.9 | 0.55 | 1.436 | 2.871 |
Total volume of foundation | 9.009 | ||||||
4. | Plinth | ||||||
4a. | Long wall | 2 | 5.9 | 0.6 | 0.45 | 1.593 | 3.186 |
4b. | Short wall | 2 | 3.2 | 0.6 | 0.45 | 0.864 | 1.728 |
| Total volume of plinth | 4.914 | |||||
5. | Room wall | ||||||
5a. | Long wall | 2 | 5.6 | 0.3 | 3.0 | 5.04 | 10.08 |
5b. | Short wall
Total volume of room wall | 2 | 3.5 | 0.3 | 3.0 | 3.15 | 6.30
16.38 |
QUIZ PRACTICE
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