House Information 01 – Foundation
Foundation or piling works are ground treatment which is by driving a pile into the ground below ground level. Except sheet pile, other piles like concrete pile, steel pile, bored pile are used to transfer the building load to the ground. It’s used to strengthen the soil so that the ground able to support the load of the building. While sheet pile is usually used to support lateral load and act as a supporting wall.
Types of House Foundation / Piling Works
a) Shallow Foundation is usually used for founding level not more than 3 metre deep from ground surface.
b) Pad Foundation is commonly used for sustaining concentrated loads from a single point load. (E.g. Structural columns.)
c) Strip foundation is used to support a line of loads such as load-bearing walls.
d) Raft foundation refers to the usage of concrete slab which extends over the whole loaded area which causes the loads from the whole structure to be spread over a large area which reduces the stress on foundation soils. Raft Foundation also prevents differential settlements.
e) A Footing is the bottom part of foundation which is made of concrete reinforced with steel. It is sometimes referred to as “spread footing” as it is spread wide which allows the vertical loads that are coming down in the building to be spread.
f) Drop Hammer Pile Driving
A pile driver is a mechanical device which is used to drive piles into the soil to provide foundation support for buildings or structures. It is usually placed upon a pile and a heavy weight will be raised till its highest point and then released; this causes the heavy weight to smash on to the pile to drive it deep into the ground.
g) “Environmental-Friendly” Jack-In Piling
A modern technique by which pre-formed piles (e.g. Prestressed Spun Piles, Precast RC Piles, H-Piles, Steel Pipe Piles) are hydraulically jacked into the ground as displacement piles.
Advantages of Jack-in Piling
i) Environmental-Friendly Piling Works for House.
- Low Noise
- Vibration Free
- Minimal Spoils Disposal
ii) Able to achieve good verticality.
iii) Lower risk of machine toppling as compared with conventional leader type machines.
iv) Every pile is jacked up to between 1.8 times – 2.5 times working load.
Micro-Piles are small in diameter which can be installed in a variety of soils ranging from poorly-graded granular soils to cohesive plastic clays. It is also known as Mini-Piles, Pin Piles, Needle Piles or Root Piles.
Micro-Pile is commonly used in areas with restricted accesses. Micro-Pile drilling methods generate minimal disturbance or vibration to adjacent structures, making Micro-Piles an excellent underpinning alternative.