EfW Project, UK

The piled waste bunker had undergone significant heave and an appraisal of potential causes of ground movement was required.

GPCL provided a range of technical inputs into the project including a review of ground investigation and CPT data, analysis of pile design and tests, analysis of several pile group models and a prediction of future settlement to the bunker and surrounding structures. After a detailed review of all ground investigation and monitoring data, it was concluded that the likely mechanisms causing the heave was a combination of:

• Ambient high porewater pressures leading to reduced pile capacity
• The installation of piles in the adjacent plot for the Administration Building causing:
  • Heave due to displacement
  • Further elevation of pore pressures
• The completion of the bunker base and the engagement of the piles under tension and the consequent uplift of the bunker as a buoyant structure.