Continuous Flight Auger Piles - A Technology Initiative for Faster Piling in India-Paper

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The paper describes an initiative by the Deep Foundations Institute of India (DFII), supported by DFI USA and hosted by the Nuclear Power Corporation of India Limited (NPCIL), to introduce Continuous Flight Auger (CFA) piling to India. CFA piles are expected to install faster than conventional bored cast-in-situ piles under suitable ground and loading conditions, while reducing the need for temporary casing and bore-stability measures and limiting noise and vibration.<br /><br />The initiative aims to demonstrate CFA construction under Indian conditions, test pile performance, and develop guidance for design, installation, and testing based on Indian standards. A field trial was planned at NPCIL’s Gorakhpur site in Haryana: six 600 mm diameter piles, approximately 18 m deep, to undergo compression, tension, and lateral load tests, as well as low-strain integrity testing. The site’s predominantly sandy silt soils and groundwater conditions informed the design.<br /><br />Key implementation challenges include producing pumpable concrete or grout with sufficient workability for reinforcement cages to be installed, adapting conventional hydraulic piling rigs with CFA equipment, and designing rigid cages that can be pushed to full depth. Continuous monitoring, quality assurance, safety, and competent personnel are also emphasized.<br /><br />At the time of publication, site investigations and draft design and execution guidance had been completed. Field trials were planned for late 2018, followed by dissemination of findings, completion of an India-specific CFA manual, and efforts toward incorporating the technology into national standards.

Keywords

Continuous Flight Auger

CFA piling

Deep Foundations Institute of India

NPCIL Gorakhpur

field trial

pile testing

Indian standards

bored cast-in-situ piles

sandy silt soil

groundwater conditions