Here I just briefing about building, its structure, loads transferred to the foundations, site selection for construction, site plan, bye – laws, types of buildings on regular basis starting with this article.
A Building is a structure consists of components like Foundation, walls, floors, roofs, beams, staircase, doors and windows related with each other.
Load Bearing Wall: which always rest on the foundation taken deep in to the earth. It transfers all loads including its self-weight, loads from slab, beams, and columns along with live load to the load of the superstructure (Structure built above Ground level) on the subsoil on which it rests. In order to give more stability at the base, wider footings will be provided for these load bearing walls.
Partition Wall: This is not a load bearing wall, which will not take any load of superstructure. It is an enclosure used for rooms and just act as a screen wall separation, rests above the floor level.
As per Structural system the buildings can be classified into 3 types
Framed structure building
It is the structural system of building consists of floors, slabs and beams with load bearing walls. Buildings up to 3 floors in general can go for load bearing structure. Here the thickness of walls at upper floors are less compared to lower floors and as a result, more carpet area is available at upper floors.
Building and its components
It is the structural system of building consists slabs and beams supported by number of columns in a systematic pattern. Here the loads from slabs are transferred to the cross beams or secondary beams, which in turn transfer it to main beams through junctions. These main beams transferred entire grid system load to the respective columns and finally to the footings. All the walls are resting over plinth beams and not over any foundations which means, no foundation is necessary for any wall. E.g.: All high raised buildings and multi-storeyed buildings.
This is the structure built with the combination of both load bearing structure as well as framed structure. Here all external walls will be considered as load bearing walls and all intermediate points will be supported by columns. This type is best suitable for, where building having large spans such as industrial buildings, halls, auditoriums, warehouses etc.
Building and its components
composite structure building
We understood clearly all types of structures, for giving more clarity we can compare load bearing walls with RC Framed structure in the following table:
|No.||Load Bearing structure||Framed structure|
|1||All walls are considered load bearing walls||All walls are treated as partition walls|
|2||All the walls are constructed with foundations||All the walls are resting overPlinth beams only|
|3||Here Wall thickness will be 230mm||Here External walls are with 200mm thick and all partition wall will have 100mm thick.|
|4||Walls will be constructed with stones, bricks or high strength solid blocks||All footings, columns, beams and slabs are built in RCC|
|5||It is not possible for dismantling load bearing walls||Here the walls can be removed and altered easily|
|6||Difficult for providing extra door, window openings other than specified locations||Any changes are possible in-between the space of two columns|
|7||Requires firm and sturdy base like hard soil, hard rock etc.||Even though the Soil having less or poor bearing capacity, by means of driving piles in to the soil till it reaches the hard strata, columns can be taken up from there.|
|8||Limited for residential buildings up to 3 floors||Best suitable for high rise buildings in a water logged regions also.|
Classification of Loads coming over foundations
The 3 types of loads are
This is the load of the material or self-weight of the materials used for the different parts of building like floors, walls, roofs, staircase, beams etc. These loads are permanent in nature.
Self-weight of different materials are tabulated here:
|No.||Material||Weight in Kg/m3|
|5||Plain Cement Concrete||2400|
|12||Doors with Frames||38|
|13||Windows with frames||28|
|15||Teak wood||6570 to 8140|
This is also called as superimposed load and it is the movable load on the floor and is variable. E.g. all loads of movable items including furniture, shelves, Kitchen items, Electronics etc.
Live loads for floors of different types of buildings are tabulated here:
|No.||Type of Building||Weight in Kg/m2|
|1||All Residential buildings, Hostels, Hospitals etc.||250|
|2||All commercial buildings, Office buildings, School buildings, light garages, churches and retail shops||400|
|3||All Public buildings, assembly halls, auditoriums, cinema halls and restaurants||500|
|4||All light manufacturing units, Heavy workshops, printing presses and Industries||750|
|5||All Ware houses, book stores, stationary stores and heavy industries||1000|
Wind load is an important aspect and should not be neglected while designing high rise buildings. The exposed surfaces of sides and roofs of such buildings are subjected to wind pressure and its effect is to reduce the pressure on the foundation on the windward side (direction or side of wind is blowing) directly and to increase the pressure on the foundation on the leeward side.(opposite direction or side of wind is blowing)
For calculating wind pressure the following formula maybe adopted
P = KV2,
Where P = Wind pressure in Kg/m2
V = Velocity of wind in Kmph
K = Coefficient depends on wind speed, temperature of air and shape of structure.