Event created by Jackson Jones
Demystifying Continuous Flight Auger (CFA) Piling
An Engineering Education Australia Webinar
Continuous flight Auger (CFA) piling was introduced in Australia in the 1970’s. The technology has been used as niche product until about 2005 and with the growth of the cities on the East Coast, CFA piling became more attractive, mainly due to high production rates compared with conventional reinforced concrete bored piles.
CFA piling can be an efficient and cost-effective method for foundation piles to transfer building loads into the suitable bearing layers. The method can also be used for embedded retaining walls like secant piled walls or contiguous piled walls, providing enhanced stiffness and water proofing performance than king post or sheet piling walls.
However, the installation process of CFA piles includes some risks which could cause significant performance issues with respect to the load-settlement behaviour of foundation piles, alignment and water proofing performance of retaining walls, the integrity of pile shafts and excessive ground movements in the proximity of the pile location. The latter has caused significant defects on existing structures due to uncontrolled settlements caused by insufficiently executed CFA piling operations.
Hence, potential installation related impacts of CFA piling on the permanent design performance and on the behaviour of adjacent structures (e.g. buildings, services, working platforms, etc.) needs to be considered when selecting CFA piles.
The webinar will introduce some of the key installation risks of CFA piling and how those risks can be assessed and mitigated. Such risk assessment and mitigation strategies depend on ground conditions, size of the selected piling equipment, adjacent buildings/ infrastructure and the overall scope of the piling works. The webinar also discusses some special requirements with respect to concrete placement, performance, technology and testing for CFA piling as a large number of defects in CFA piles are related to inadequate concrete performance.
Learning outcomes
- Understand the benefits of CFA piling technology
- Understand the key risks associated with CFA piling
- Gain applicable strategies for the mitigation of risk when using the technology
- Learn some of the special requirements associated with CFA piling such as concrete placement, performance, technology and testing
Is this course for you?
This webinar is suitable for professionals in the building and construction industry involved in ensuring or assessing the structural integrity of new builds.
Topics we'll cover
- Introduction of the general methodology of Continuous Flight Auger (CFA) piling and typical areas of it's application for foundation piles, retention systems and ground improvement schemes
- Introduction of the key advantages and major risks of CFA piling, especially in granular soil conditions below the ground water levels
- Discussion of some robust risk assessment and potential mitigation strategies for CFA piles during the drilling and the concrete placement process
- Discussion of general concrete technology and suitable testing requirements for CFA piling
Facilitator
Dr Martin Larisch is a Principal Geotechnical Engineer and Technical Leader for Jacobs in ANZ. Before joining Jacobs in 2020, he worked for various specialist piling and ground improvement contractors in Australia, New Zealand and Germany for more than 20 years in various technical and operational leadership roles. He was also affiliated with The University of Queensland in Brisbane as an Adjunct Associate Professor from 2014 until 2021, where he investigated installation effects of CFA and Drilled Displacement Auger systems on the permanent pile performance.