The foundation of your house is critical part of its structure as it helps distribute the load and minimised distress against the foundation soil movement , there by keeping the building and secure. Hense, foundation are critical to the structural safety of a building.
Depending on the depth of the soil in which the foundation is made , there are two types of foundation used in construction building:
01. Shallow Foundation :-- These are use to small and light building. They are commonly reffered to as spread footing or open footings. There are four types of shallow foundation:
- Individual footing is isolated footing.
- Combined footing.
- Strip foundation.
- Raft or Mat foundation.
02. Deep Foundation :-- These are used for large structure. There are two main type of deep foundation:
- Pile Foundation.
- Drilled Shafts or Caissons
The foundation should be study enough to bear the load of the structure. Therefore lkarge area footings are needed to spread the vertical load, improving the stability of the building. Different kind of footings are design based on the soil type , the type of structure, and other local requirements arising during the design process.
The different type of footing are use in construction are described below:--
01. Continuous Wall Footing:--
The footing which supported a long mesonary or RCC wall is known as a continuous footing. It can be either simple or stepped.
Generally width of the footing should be at least equal to twice the width of wall that is rested on it. In this case , the width of the footing is smaller than length of the footing, offering continious vertical support to the structure. Basically it runs throughout the length of the wall. This type of footing is not economical.
Use of continious Wall Footing: Continious wall footings are used to support the foundation walls and load-bearing walls.
02. Isolated Footing:--
A footing that supports an individual column is known as Isolated footing. This kind of footing can be Pad, stepped, sloped and with isolated beam and slab, where good soil is available. this footing are economical.
Use of Isolated Footing: Isolated footing are used as shallow foundation in order totransfer concentrated load to the ground.
03. Combined Footing:--
A footing that support two or more columns is known as combined footings. It is used two or more column are close to each other or two or more individual footings of a column would overlap. Combined footing may be trapezoidal or rectangular of a plan. A trapezoidal footing is provide when the load of one column is greater than the other.
Use of Combined footing: Combined footing are used to transfer bload to closely spaced column to the ground or when the column place the boundary of plot.
04. Strip Footing:--
A footing which support a number of column in a line has to be a combined footing is known as Strip footing. It is used when the row of a column is closely space and there spread footings overlap the each other. Astrip footing is also known as a continuous footings.
Use of Strip footing: Strip footing are used to transfer the loads to closely row of column to the ground.
05. Strap Footing:--
W hen a distance between the two columns supported on combined footing become large, the cost increase rapidly. The strap footing is an economical option in such cases.
Use of Strap Footing: Generally, strap footings are used to conjuction with column of adjoining property.
06. Raft Footing:--
If load transmitted by the column in a structure are heavy and the soil pressure is smaller than the footing requires more area. In such a case it maybe better to provides continuous footing under all columns and wall. Such kind of footing is called a Raft footing.
Use of Raft Footing: It is widely used when soil has low load bearing capacity.
07. Pile Footing:--
When the soil has a low beariung capacity or the ground water level is high, pile footings are applied. Piles are common while building foundation for btidge , Dam etc. And when a load is gradually applied on a foundation , sattlement occures, which is almost elastic, to begain with the ultimate load, Share failure occurs when a plastic yeild of surface develop under the footing. Extending down ward and upward to the ground surface, and catastrophic settlement or rotation of the foundation occures. Which may fall the foundationof the building.
Use of Pile Footing: Piles are used as deep foundation where the soil is very week and has higher ground water level.
Pile Footing
Please write a detail description about pile foundation
ReplyDeleteOk.
Delete