Richard Ball and Nick Langdon, CGL Card Geotechnics, and Mark Creighton, Galliford Try Construction. This paper was first published in GE’s September 2014 issue.
This paper presents a case study regarding the prediction of party wall movements using Ciria Report C580 – Embedded retaining walls, guidance for economic design for the cased small diameter continuous flight auger (CFA) piles that formed the basement box for a site in Pont Street, London.
Installation movements were determined based on Ciria C580 case study data for pile lengths which varied around the perimeter of the basement from 10m to 22m. Extensive monitoring was installed and monitored continuously during construction through 2011 and into 2012. The results are compared to original predictions and it is concluded that installation movement predictions from Ciria guidance can be significantly reduced for controlled contiguous piled wall installations with consequent benefits to party wall negotiations.