Publication Abstract

Proceeding of the 2018 DFI-EFFC International Conference on Deep Foundations and Ground Improvement, Rome, Italy, (DFI, EFFC)

Threaded Rotary Bored Piles at Paddington New Yard
David A. Hard and Ana T. Carvalho

This paper addresses a technique that has been developed to improve the pile efficiency through the modification of existing rotary bored pile techniques. This is achieved by the creation of a thread around the main straight shaft of the pile, enhancing the interface with the ground. This mechanism allows a greater load to be carried than the equivalent full concreted section, whilst reducing the volume of concrete and volume of pile spoil. Following ten years of development, SolThread was delivered by Bachy Soletanche for the first time in 2014 on the Crossrail site at Paddington New Yard, as a sustainable alternative to conventional piles. Remote access inspection techniques were used to demonstrate the effectiveness of the threading process, combined with static load tests to validate the design assumptions. The paper presents the construction methodology and discusses the advantages and drawbacks of this technique based on lessons learned from this project. The successful implementation of the pile method at Paddington New Yard has allowed the verification of the technique as a practical alternative to traditional rotary bored piles. Static load tests have been used to verify the design parameters and predicted 40% enhancement in shaft friction produced through the creation of the threads.

 article #3005; publication #1040 (ROME-2018)