Underpinning is a process that increases the strength of an existing foundation system.
Underpinning can be done as follows:
The foundation system may not be able to support the weight of a building.
Buildings are either expanding or changing to accommodate a different type of activity that puts a greater load on the building than its bearing capacity.
The construction of a large building with deep foundations and basements next to an existing building can have a significant impact on the building.
Types of Underpinning
The purpose of underpinning is to strengthen the foundation system by extending the existing foundations or joining them with new ones. It also enhances the properties of soil beneath the foundations without touching the building.
UNDERPINNING METHODO 1: PIT METHOD
The following is the way it is done:
In the beginning, a temporary system of foundation is constructed around the existing one.
To reduce the load-bearing, a pit will be dug under and around the existing foundations.
Then, the concrete pit is filled with a new foundation.
Once the concrete has been set, the temporary foundations will be removed to stabilize the load onto the new foundation system.
Each section is 8′ to 12′ long (2 – 4m approx), depending on the size of the building. Each unit is 8′ to 12 feet long (approximately 2 – 4m), depending on the size and shape of the building. The old sections are interspersed with the new to secure the system.
UNDERPINNING METHODOLOGY 2: NEEDLE BEAM METHOD
This is done in the following way :
Two micro piles at a distance are initially built with a micropiling machine.
Then, a large hole is made to catch the needle beam.
The RCC needle beams are built over the piles and inside the foundation walls.
Fill in the earth immediately after the beam has been set. The new foundation system can now handle the additional load.
This method does not affect the interior of the building.
UNDERPINNING METHODO 3: MICROPILING METHOD
The following methods are used:
The micropile is built at an angle just below the existing foundation.
Excavate the earth to the top of the pile.
Then, remove all the earth between the pile of soil and the existing foundation by hand. This will create a cone-shaped void on top of the micropile.
Concrete can be used to fill in the void. Once the micropile is in place, the existing foundation can transfer forces to it, increasing its strength.
Repeat this process on a regular basis.
A platform is an elevator that can be open or enclosed. It’s used to lift people or cargo to higher floors within a building. Elevators are a part of every high-rise commercial or residential structure.
Raw Materials
The steel framework is used to build the elevator car. This helps maintain the longevity and strength of the structure. The crosshead is a set of steel beams that extends the elevator shaft from side to side over the car and holds the pulley used for the hoist cable. From the crosshead, a steel structure called a sling extends down the side of the vehicle to support the platform or floor.
Normally, the sides of an elevator car for passengers are made from steel sheets and are trimmed on the interior with elegant paneling. The car’s floor is available in either tiled or carpeted versions. The interior trim and handrails are made of stainless steel to resist abrasion and display. The suspended ceiling consists of fluorescent lighting on plastic diffuser panels and is usually suspended under the top of the vehicle. Behind panels in front of the car and adjacent to the doors are the elevator controls, emergency phone, and alarm buttons.
Steel guide rollers are attached to the top and bottom sides of the sling to remove the guide rails. The guide rails, made of steel, are attached to the walls of the elevator shaft from top to bottom. The emergency brake system has two clamping faces that are pressed together by a wedge in order to encourage the guide rail. The wedge is operated by a screw that is moved by a roller stuck to the emergency cable.
The structural component of lifts:
These are the main components of an elevator lift.
- The Moist Way or Shaft or Lift Well
- Machine Room
- Lift Lit
Categorization for Lift Elevator:
- Drum Type- Wounds on a rope around a drum
- Traction Type- Pulley/Breaks/Motor
- Gearless
- Geared