foundation the foundation poetry foundation foundation serie

 foundation the foundation poetry foundation foundation serie

What is Foundation?

Definition: The lowest part of a building that is in direct contact with the soil and transfers structural loads safely to the ground is called a foundation.

The foundation acts as a load-transferring medium between the superstructure and the soil. It ensures that the stresses transmitted to the soil remain within its safe bearing capacity. If the soil beneath the foundation is not strong enough, excessive settlement may occur, leading to cracks or structural failure.

Therefore, soil investigation and proper foundation selection are essential before constructing any structure. A weak foundation can result in severe damage, especially during earthquakes, floods, or other natural hazards.

Types of Foundation

In general, all foundations are divided into two categories, - shallow and deep foundations. The terms Shallow and Deep Foundation refer to the depth of the soil at which it is placed. Generally, if the width of the foundation is greater than the depth, it is labeled as the “Shallow Foundation”. If the width is smaller than the depth of the foundation it is called a “Deep Foundation

1. Isolated Spread Footing

This is the most widely recognized and most straightforward shallow foundation type, as this is the most economical type. They are typically utilized for shallow establishments to convey and spread concentrated burdens caused, for instance, by pillars or columns. They are generally used for ordinary buildings (Typically up to five stories).

Isolated footing comprises a foundation directly at the base of the segment. Generally, every section has its footing. They straightforwardly transfer the loads from the column to the soil. It might be rectangular, square, or roundabout. It can comprise both reinforced and non-reinforced material. For the non-reinforced footing, however, the stature of the footing has to be more prominent to give the vital spreading of the load. They should possibly be utilized when it is sure beyond a shadow of a doubt that no differing settlements will happen under the whole structure. Spread footings are inadmissible for the orientation of large loads. It is given to lessen the twisting minutes and shearing powers in their primary areas.

2. Wall Footing or Strip footing

Wall footing is also known as continuous footing. This type is used to distribute loads of structural or non-structural load-bearing walls to the ground in such a way that the load-bearing limit of the soil isn't outperformed. It runs along the direction of the wall. The width of the wall foundation is usually 2-3 times the width of the wall.

 

3. Combined Footing

The combined footing is very similar to the isolated footing. When the columns of the structure are carefully placed, or the bearing capacity of the soil is low and their footing overlaps each other, combined footing is provided. It is fundamentally a blend of different footings, which uses the properties of various balances in a single footing dependent on the necessity of the structure.

4.Cantilever or Strap Footing

Strap footings are similar to combined footings. The reasons for considering or choosing strap footing are identical to the combined one.

In strap footing, the foundation under the columns is built individually and connected by a strap beam. Generally, when the edge of the footing cannot be extended beyond the property line, the exterior footing is connected by a strap beam with the interior footing.

 5.Raft or Mat Foundation

Raft or Mat foundations are used where other shallow or pile foundations are not suitable. It is also recommended in situations where the bearing capacity of the soil is inadequate, the load of the structure is to be distributed over a large area, or the structure is subjected continuously to shocks or jerks.

A raft foundation consists of a reinforced concrete slab or T-beam slab placed over the entire area of the structure. In this type, the whole basement floor slab acts as the foundation. The total load of the structure is spread evenly over the entire area of the structure. This is called a raft because, in this case, the building seems like a vessel that floats on a sea of soil.

Deep Foundations

Several Types of Deep Foundations Are Discussed Below.

Types of Deep Foundation.

The followings are the types of deep foundations. 

1. Pile Foundation

Pile is a common type of deep foundation. They are used to reduce cost, and when as per soil condition considerations, it is desirable to transmit loads to soil strata that are beyond the reach of shallow foundations.

The followings are the types of pile foundations.

1.      Based on Function or Use

1.      Sheet Piles

2.    Load Bearing Piles

3.    End Bearing Piles

4.    Friction Piles

5.     Soil Compactor Piles

2.    Based on Materials and Construction Method

1.      Timber Piles

2.    Concrete Piles

3.    Steel Piles

4.    Composite Piles

2. Pier Foundation

Pier is an underground structure that transmits a more massive load, which cannot be carried by shallow foundations. It is usually shallower than piles. The pier foundation is generally utilized in multi-story structures. Since the base region is determined by the plan strategy for the regular establishment, the single pier load test is wiped out. Along these lines, it is increasingly well-known under tight conditions.

3. Caisson Foundation

Caisson foundation is a watertight retaining structure used as a bridge pier, construction of the dam, etc. It is generally used in structures that require a foundation beneath a river or similar water bodies. The reason for choosing the caisson is that it can be floated to the desired location and then sunk into place.

 

A caisson foundation is a ready-made hollow cylinder depressed into the soil up to the desired level and then filled with concrete, which ultimately converts to a foundation. It is mostly used as bridge piers. Caissons are sensitive to construction procedures and lack construction expertise.

There are several types of caisson foundations.

1.      Box Caissons.

2.    Floating Caissons.

3.    Pneumatic Caissons.

4.    Open Caissons.

5.     Sheeted Caissons.

6.    Excavated Caissons.