Use of pier foundation and under ream piles
Pier base:
pier foundation and under rim piles: Where sandy soils or soft soils or black cotton soils have hard layers of shallow depths inside, pier foundations are used to shift the loads of more bearing structures to harder layers. The base of the pier is usually round. The difference between bearing piles is that the piles are constructed by filling the soil with concrete. On the other hand, the bearing pile is placed by hitting the hammer. Pigeons can also be placed under water. It can be made of brick, RCC steel, cast iron and concrete etc. The pier can be solid cross-section. If it is hollow in size, it has to be filled with weak concrete, sand, ash, stone or any other solid inert material.
The diameter or minimum dimension of the pier shall not be less than 1 2 of the height of the pier. The nature of the soil and the mutual distance are determined.
Advantages of Pier Base:
pier foundation and under rim piles
1. Piles are constructed when it is not possible to place piles due to poor soil condition.
2. The ground does not vibrate to build piers.
3. It prevents lateral movement of soil.
4. Lighting equipment is required.
5. Construction costs are low.
. Quite convenient to carry more load.
Disadvantages of foot foundation:
pier foundation and under rim piles
1. Not to be used for general purposes.
2. Sufficient care has to be taken while making.
3. Skilled craftsmanship is required.
Under-rimmed piles
Black cotton soil, filled soils, soils with low bearing capacity and compressive expansion can all cause cracks in the structure. So this pile is used to prevent relative movement of soil. This type of pile is provided as anchor. This anchor is given to the soil at such a depth that the soil is free from natural influences.
The under rim pile is placed like a cast-in-situ pile. However, at the lower end of it, i.e. near the base, it is enlarged like a bulb. Providing a bulb is called a single under rim pile. Providing an extra bulb increases the bearing capacity by about 50%. Increasing the number of bulbs will increase the bearing capacity and piles will be used for multi-storied buildings. The construction method of this pile is very simple. Holes with the required depth are dug with the help of manual agar. An under rimmer is used to enlarge the base. Above the soil collection bucket, two sets of claspable blades are attached to a rod called an under reamer.
Blood is exposed by inserting the under rimmer into the steep hole. The reamer is then slowly turned and the soil is cut and filled into buckets. When the bucket is filled, the floor cover is lifted and the soil is removed. Thus the rim is made at the bottom of the hole. The diameter of the under rim pile is 20 to 50 cm and the diameter of the bulb of the rim is between two and three of the diameter of the pile. The distance between the two adjacent rims varies from 1.25 to 1.5 times the diameter of the bulb, and the pile is 3 to 6 meters long. The piles are conveniently connected by camping beams. The capping beam will be 8 to 12 cm above the ground level. It is left empty to move the soil side. The bearing capacity of under rim piles is increased in the following ways--
1. Increases the number of bulbs
2. Increases the length of the pile
3. Increases the diameter of the pile
4.Failure of spread footing
Spread footing can fail in the following ways--
pier foundation and under rim piles
1. By shearing
2. Bending or rupture
3. Become crushing
4. By spreading.
1. By shearing:
The part of the bezel on which the wool will be placed becomes the punching shear of the wall's own weight and sitting down is called the shearing failure. As a result of the failure, the extended parts on both sides of the base rise to the top under the pressure of the soil.
2. By bending:
If the base beige fails due to curvature, i.e. the lower base of the wall, cracking due to bending, it is called bending failure. These cracks can occur in the middle of the base or directly below the edge of the wall.
3. By crushing
When used in a base based on weak construction materials, the base can break and crumble under the pressure of the wall, this type of failure is called foundation failure.
4. By spreading:
In the case of clay or black cotton soils, lateral soil erosion occurs. As a result the foundation spreads and fails, such a failure is called spread failure.
pier foundation and under rim piles:
1. By shearing:
The part of the bezel on which the wool will be placed becomes the punching shear of the wall's own weight and sitting down is called the shearing failure. As a result of the failure, the extended parts on both sides of the base rise to the top under the pressure of the soil.
2. By bending:
If the base beige fails due to curvature, i.e. the lower base of the wall, cracking due to bending, it is called bending failure. These cracks can occur in the middle of the base or directly below the edge of the wall.
3. By crushing:
When used in a base based on weak construction materials, the base can break and crumble under the pressure of the wall, this type of failure is called foundation failure.
4. By spreading:
In the case of clay or black cotton soils, lateral soil erosion occurs. As a result the foundation spreads and fails, such a failure is called spread failure.