CFA piling is a versatile solution for various ground conditions and soil types. Such ground types can include:
- Sand
- Gravel
- Weaker rock
- Silts
- Clay
CFA piles are popular for piling in the UK due to their versatility and effectiveness.
Contractors use CFA piling for constructing piled embedded walls in various ground conditions and soil types. CFA piling is a versatile solution that works well for different types of piles, including king post walls, contiguous piled walls, and secant piled retaining walls.
Contact our expert piling team/engineers for advice on your project and get a no obligation quote
What We Offer
- Free site visits
- Free no obligation quotes
- 12 Year warranty of all work
- Estimates based on detailed tender stage designs
The CFA Piling Process
Instrumented piling rigs create CFA piles by closely monitoring the process. As the auger drills down and pours concrete, the piles are formed all at once.
The CFA piling method is fast and efficient, generating low levels of noise, and is virtually vibration free.
Step 1 – Before the rig arrives on site, the client surveys the area for utilities. They will then prepare a working platform at the foundation level and place a numbered pin at each pile position on the platform.
Step 2 – A health and safety briefing will take place, the rig will be prepared to work, and moved to the first pile position.
Step 3 – The operator positions the auger over the marked point and sets it to zero at the working platform level. They then drill the auger to a predetermined depth, pausing occasionally to bring spoil to the surface.
Step 4 – The team will bring readymix concrete to the site and pump it into the rig through hoses attached to the auger. The rig operator removes the auger string while continuously adding concrete to keep the borehole from collapsing. We use CFA rigs that use computers to show us a live view of the pile diameter as the auger is pulled out.
Step 5 – The attendant excavator clears spoil from piling mat level, exposing the fresh concrete at the head of the pile.
Step 6 – A reinforcement cage, designed to meet the specifications, is placed into the fresh concrete. This is to ensure a strong connection between the piles and the reinforced concrete foundation.
When are CFA Piles used?
CFA piling is used in many projects, including residential housing, commercial developments, and large civil engineering works.
They are equally suited to piled raft slab and traditional ground beam and pile cap applications.
CFA piling works well for building not only bearing piles but also contiguous, secant, and king post retaining walls.
With CFA rigs that have a pull-down function and rock augers, like those in our fleet, we can install CFA piles through weak rock formations. This avoids the need for more costly drilling methods like percussive or rotary bored piling.
To get a better understanding of when CFA piling is used, check out our case studies pages.
Our Piling Rigs
Our rigs are equipped with on-board instrumentation systems to ensure high quality pile construction and record keeping.
Our current augered piling fleet consists of:
CFA
- Comacchio CH 450
- Soilmec SR30
- Soilmec R312
- Geax EK110
- Geax EK75
SFA
- Hutte HBR204
- Hutte HBR203
You can learn more about our rig collection on our fleet page.
FAQ’s
Q – What equipment is needed for cfa piles?
A – CFA piles are installed using specialist drilling rigs. The drilling rigs in GeMech’s owned fleet range from 5.0t up to a maximum of 50.0t. The CFA drilling rig will be supplement on site by a trailer mounted concrete pump, a concrete agitator drum, and an attending excavator. The attending excavator is typically provided by the Client, but can be provided by GeMech when necessary.
Q – How many cfa piles can be done per day?
A – Daily production rates are dependant on a number of factors, including but not limited to, rig size, pile diameter, pile depth, ground conditions, material availability, and site logistics.
For our larger rigs > 25.0t, we would typically expect to install between 10 & 35 piles per day, whereas using our < 25.0t rigs we might expect to install anywhere between 5 & 20 piles per day.
Q – How are CFA piles reinforced?
A – After the concrete is poured, a steel reinforcement cage or steel bars are inserted into the wet concrete to provide additional structural strength.
Capabilities:
- Pile diameter 300mm – 900mm
- Maximum depth 25.0m
- Working loads up to 3,300kN
