Loads
The loads coming on the foundations are generally divided into (i) Live Load (ii) Dead Load (iii) Wind Load and (iv) Snow load.
(i) Live Load:
It is a temporary or moving load. The weight of the inhabitants of a building, the weight of furniture or any stored material is called Live Load. Sometimes the live load is also called super-imposed load. For designing foundations, the live load on the structure is also taken into account.
(ii) Dead Load:
It is the permanent load of the structure, i.e. the weight of the structure itself. The weight of the walls, floors, roofs, weight of fixed machinery and any immovable load, is called dead load.
(iii) Wind load:
When the wind blows, it causes a lateral thrust or pressure on the vertical as wall as the inclined embers of the structure. This wind pressure is called wind load. The ten decay of the wind load wind load is to over-turn the structure. The wind pressure has severe effect on tall buildings but has very little effect on small buildings. Hence the building by-laws specify that if the height of a building is less than twice its width this wind pressure should be neglected, provided that the building is stiffened by cross-walls, roofs, floors etc.
(iv) Snow load:
In places which have a heavy snow-fall, the roofs have to bear the load of the snow in addition to the dead and live loads, therefore, at the time of designing it should also be taken into account. But when the roofs are sloping to an angle of 45°, i.e. 1 in 1 or more, no account of the snow load is made. In India while building in hill stations, snow load is taken into account.
DEAD WEIGHT OF VARIOUS MATERIALS
| Item | Weight | Item | Weight | |
Excavated Materials |
Building Materials |
1600 kg/m3 |
||
| Clay (dry) | 1600kg/m3 | |||
| Clay (damp, plastic) | 1760 kg/m3 | Brick (ordinary) | 1400 kg/m3 | |
| Earth (dry, loose) | 1209 kg/m3 | Cement (loose) | 27OO kg/m3 | |
| Earth (packed) | 1520 kg/m3 | Chalk Glass | 2560 kg/in3 | |
| Sand (dry, loose) | 144 -170 kg/m3 | Limestone | 2650 kg/m3 | |
| Sand (dry, packed)
|
1600-1900 kg/m5 | Sandstone | 2800 kg/m3 | |
| Steel | 7800 kg/m3 | |||
| Timber | 650-750 kg/m3 | |||
Structure Items |
Finished Items |
|||
| A.C. Sheets
|
17 kg/m2
|
A.C. Sheet roof
|
34 kg/m2
|
|
| Brick masonry (ordinary)
|
1920 kg/m3
|
C.G.I. Sheet roof | 10 kg/m2
|
|
|
Brick wall (10 cm thick)
|
295 kg/m2
|
Allahabad tiles (Single) roof |
83 kg/m2
|
|
| Brick wall (20 cm thick)
|
440 kg/m2
|
Allahabad tiles (double) roof | 160 kg/m2
|
|
| Cement-plaster (2 5 cm thick)
|
44 kg/m2
|
Country tiles roof
|
70 kg/m2
|
|
| Concrete
|
2306 kg/m3
|
Country tiles (double roof) | 115kg/m2
|
|
| G.I. Sheets (24 gauge)
|
5 kg/m2
|
Manglore tiles with battens
|
69 kg/m2
|
|
| G.I. Sheets (16 gauge) | 10 kg/m2 | |||
|
Rubble masonry
|
2000 kg/m3
|
Timber trusses and purlins |
12 kg/m2
|
|
| Ashlar masonry
|
2200kg/m3
|
Doors with frames | 39 kg/m2 | |
Minimum Live Loads on Different Types of Floors |
||||
| 1 | Residential building floors (including dwelling houses) | 200 kg/m2 | ||
| 2 | Hospital wards, bed-rooms and private sitting rooms in hostels and dormitories | 200 kg/m2 | ||
| 3 | Office floors (excluding entrance halls and light work rooms) | 250.400 kg/m2 | ||
| 4 | Floors of banking halls, office entrance halls, reading rooms | 300 kg/m2 | ||
| 5 | Shop Floors | 400 kg/m2 | ||
| 6 | Floors of warehouses, workshop, factories (for light weight), dancing halls, waiting halls and public looms of hotels | 500 kg/m2 | ||
| 7 | Floors of warehouses, workshops, factories (for medium weight)
|
750 kg/m2 | ||
| 8 | Floors of warehouses, workshops, factories (for heavy weight) | 1000 kg/m2 | ||