Having done some research into this type of build I’ve learnt that pile foundations are the most common foundations used.
Pile foundations are deep foundations, which are made of long columns of reinforced concrete, for the foundations to be classed as piles their depth needs to be more than three times the breadth of the building. due to the lack of communication I haven’t been able to find out whether the concrete piles are pre-cast or cast-in place.
There are pros and cons for both type of concrete piles.
Pre-cast:
Advantages:
- Provides high resistance to biological weathering
- Maintain a high strength
- Pre-cast piles can increase the pace of work
- The quality of the piles can be maintained and regulated before being placed into the ground
Disadvantages:
- Once the pile is made it is very hard to increase and decrease the length of the pile afterwards
- They are hard to transport from factory to site can cause delay in project due to the time taken to custom make for specific sites
- There is a possibility that the during the transport of the foundations that they get damaged which can in turn cause delays to the work schedule
- They require heavy and expensive equipment to drive
Cast-in-place piles
Advantages:
- The shells are light-weight so they are easier to handle
- length of the piles can be changed easily
- Minimal measures are required to prevent damage while handling
- Very hard to break when installing into the ground
Disadvantages:
- Requires careful supervision when installing
- Needs enough space to store on site
- If not reinforced properly the pile can fail if too much tension is applied
- The bottom of the pile may not be symmetrical
Before the pile can be made the ground has to be excavated using hydraulic drivers which are pushed into the ground by hydraulic arms.