Marriott Hotel, Edinburgh

LocationBaxters Place, Edinburgh
RequirementEmbedded retaining wall and bearing piles for a new hotel
Main ContractorInterserve

Project Overview

A new major 240 bed Marriott hotel in the centre of Edinburgh required piled foundations and 2 storeys of retention to facilitate the construction of its basement. Large conventional piling rigs were unsuitable due to the severely sloping site.

The ground conditions were predominantly granular soils, which made it ideal for grouted micropiles.

Project Challenges

  • Retaining wall piles installed within 500mm of existing tenement.
  • Steeply sloping site in City Centre location bounded buildings and roads.
  • Sensitivity of adjacent structures to vibration.
  • Careful planning of storage and cement/reinforcement deliveries.
  • Tight programme.

Solution Delivered

TechnikGS Modified Micropile solution was utilised, where piles were drilled to the design depth, using rotary percussive drilling with grout flush. The pile was then appropriately reinforced, which on this occasion was a more cost effective option than using hollow bar (self-drill bars) due to the extent of reinforcement. One of the main advantages of the TGS micropiles was the speed of installation and production rates. 150m/day were achieved on this project.

Working closely with the Main Contractor, eight preliminary piles were installed around the site which were statically load tested to failure, to ensure appropriate Factor of Safety.

The works were completed on schedule and proved to be the optimum geotechnical solution for this project.