Introduction of Foundation:
- Foundation is one of the most important parts of the building. The foundation plays a crucial role in the structure and it is the lowermost part of the building below the ground level which provides a base for the structure.
- Foundation is the main part of the building which receives the total load of the structure and transfer it safely to the underneath strata without any settlement of the soil.
- It is very necessary that the foundation of the structure should be placed with proper study and understanding of the ground conditions otherwise it may lead to the unequal settlement and failure of the foundation.
- In this article, you will get to know what is the foundation, different types of foundation which are used for the construction of various structures.
- It is very necessary that before doing Foundation construction the bearing capacity of soil should be studied and checked properly.
- The footing is a part of the foundation which provides stability and prevents unequal settlement of the foundation.
- The main purpose of providing footing is to distribute the total load coming from the structure to the larger area.
Functions of Foundation:
There are various functions of foundations which are as
- The main function of the foundation is to distribute the load of the building where the larger area to avoid the overloading of the soil.
- The foundation provides a level surface for the building operations.
- The foundation will help to take the total load of the structure deep into the ground.
- The foundation provides the stability to the building and prevents overturning.
Requirements of Good Foundation:
There are various requirements of a good foundation
- Location of the Foundation.
- Settlement of Foundation.
- Durability of Foundation.
- Stability of Foundation.
#1. Location of Foundation:
- The location of the foundation should be such that it can be able to resist the total load of the structure.
- Foundation must be located at an appropriate location and design as per the bearing capacity of the soil.
#2. Settlement of Foundation:
- The main function of the foundation is to prevent the settlement of the foundation. The settlement of the foundation mainly depends upon soil strata.
- The foundation of the structure should not be settled under the action of load and it should prevent the differential settlement of the structure.
#3. Durability of Foundation:
- Durability is also important aspects should be considered while foundation construction.
- The foundation of the structure should be constructed such that it should be durable. The foundation should be designed such that it should be able to carry the Lord of the structure and prevent settlement of the foundation.
#4. Stability of Foundation:
- One of the most important functions of the foundation is to provide stability such that it should be able to safely transfer the load into the soil.
What Is Foundation Engineering?
- Foundation Engineering is a branch of civil engineering which deals with the design and study of the foundation of the structure.
- Foundation Engineering is used to apply the knowledge of soil mechanics, structural engineering, rock mechanics and geology to study and design the foundation of the buildings.
Types of Foundation:
There are different types of foundations which are as follows
- Shallow Foundation
- Deep Foundation
#1. Shallow Foundation:
- Shallow Foundation is the foundation types whose death is equal or less than the width of the foundation. Shallow Foundation is one of the most commonly used Foundation.
- Shallow Foundation is generally used for today top 5m to 4m and it is generally constructed above the water table. The base of the structure is spread to provide individual support.
Types of Shallow Foundations:
- Wall Footing.
- Isolated Footing.
- Combined Footing.
- Inverted Arch Footing.
- Cantilever Footing.
- Grillage Footing.
- Raft or Mat Foundations.
The detailed explanation of foundation types are as follows
#a. Wall Footing:
- There are two different types of wall footings one is simple footing and seconds its stepped wall footing.
- For lightweight or temporary structure, simple wall footings are generally used because it has a concrete base below the walls with no steps on the wall.
- In the case of the load-bearing structure, the wall area is spread step by step till the foundation level, it is known as Stepped Foundation.
- The simple footing is used under the compound walls and lightweight structures whereas the stepped footing are used under the load-bearing structure.
#b. Isolated Footing:
- The isolated footing is used to support individual columns which are step-type or have projections in the concrete base.
- In case of the isolated footing songs, 15 cm offset is generally provided on all sides of the concrete bed.
#c. Combined Footing:
- There are some special cases in which there are two columns are located near each other in the structure layout plan.
- It is not possible to provide individual columns which may interfere or overlap each other. In the combined footing is it is necessary that the centre of gravity of column loads and the centroid of the footing should coincide with each other.
- There are two types of combined footing one is rectangular combined footing and second is trapezoidal combined footing.
#d. Inverted Arch Footing:
- This type of foundation is outdated Foundation and that is not generally used for the construction of the foundation.
- The inverted arch footings are suitable for the construction of the bridges, tanks, underground sewers and reservoirs.
#e. Cantilever Footing or Strap Footing:
- Cantilever footing is also known as strap footing. This type of footing is suitable when the column is located near the boundary of the plot and it is not possible to permit the footing of that column to exceed beyond the plot boundary.
- The strap beam is provided in this type of footing which helps to co-ordinate and support the load of the column which is located on the boundary. The strap beam helps to connect two different columns.
#f. Grillage Foundation:
- Grillage Foundation is the type of foundation which is used to transmit the heavy load from columns to the underneath soil strata which has low bearing capacity.
- This type of footing consists of steel beams in one or two tiers. Space between beams is filled with concrete to protect steel beams from corrosion.
#g. Raft or Mat Foundation:
- Raft Foundation are suitable where the ground is soft or marshy which has a very low bearing capacity and where the subsoil water conditions are uncertain.
- This type of foundations is made on the clayey soil. Raft Foundation consists of thick reinforced concrete slab covering the entire area of the bottom of the structure.
#2. Deep Foundation:
- Deep foundations are the foundations whose depth is more than its width. The main function of the deep foundation used to transmit the total load of the structure to the firm layers deep inside the ground.
- Deep foundations are constructed where the structure is susceptible to unequal settlements.
Types of Deep Foundations:
The deep foundations are categorised into the following two types
- Pile Foundation
- Well Foundation
#a. Pile Foundation:
- Pile Foundation is defined as the slender column which is capable of transferring the structure load to the underneath soil strata.
#b. Well Foundation:
- Well Foundation consists of the construction of Caissons. It is a watertight structure which is constructed with the wood, steel and RCC in connection with excavation for the foundation.