CFA piling allows the accuracy and reducing the ground settlement risk with the latest development technologies.
When the soft and loose material is over the rigid ground at the depth, the rate of the penetration will slow down the continuous flight can act like an Archimedes Screw in the soft material above. The soft or loose material gets drawn onto the auger and flighted upwards towards the surface.
Temeltek utilizes cased flight auger pile system in specific ground conditions as specified above. This method allows the continuous flight auger to bore within a casing which penetrates into the ground simultaneously with the auger. If hard layers of the earth are encountered at depth, thanks to its protective casing, no material can be entrained onto the auger. The casing will be withdrawn once the casting procedure is completed.
Continuous Flight Auger (CFA) Piling reduces the vibration level and it is a fast and cost-effective technique. It is a cast in-situ process, very suited to soft ground where deep casings or utilization of drilling support fluids might otherwise be needed. CFA piling is a non displacement piling system; in addition to this the excavated soil from the pile is transferred to the surface. CFA piles can be an attractive alternative to conventional bored piles (faster installation) and to driven piles (much less noise and vibration).
CFA piles can be used for load transfer beneath structural elements and also for contiguous and secant (interlocking) piled retaining walls. The construction sequence consists of;
- drilling a full length auger with a temporary casing into the soil using a constant penetration rate.
- Once the design level is achieved, the concrete is casted through the temporary casing of the auger as the auger is extracted. The auger should remain in the concrete during the procedure.
- during the casting operation, positive concrete pressure should be maintained. CFA piles have to be poured to platform level to facilitate reinforcement installation and avoid pile necking.
- Casting the concrete, the reinforcement cage is plunged into the concrete.
CFA method provides the following advantages
- Diameters from 450 to 1200mm
- Depths up to 32m
- Able to carry high load/ shear/ moment capacity
- Low noise and vibration
- Speed of installation
- Can overcome Interbedded clays and sands
- Can deal with water bearing sands and gravels and penetrate weak rocks
Temeltek is an experienced geotechnical engineering company for your CFA piling application with effective construction techniques on different geotechnical conditions. Temeltek provides full engineering in providing the right concrete mix design meeting the standards along with the right type of machinery which will prevent the downtime in your projects.