Thermal Consolidation and Downdrag Induced Settlement

The subject facility exhibited severe degrees of distresses and damages.  The observed damages consisted of excessive settlements and horizontal soil movement leading to damage to some of the pile foundations (separation from sleepers and tilting).

SolidEarth developed the scope for investigation with the objective of understanding the distress mechanism, qualifying the condition of the existing piles, identifying the piles to be remediated, and exploring various remediation strategies.

The scope of work completed by SolidEarth for this phase was divided into four main stages, as follows:

• Reviewing existing information, including original soil investigation reports, pad construction and operation details, available pile design and installation records, as-built drawings, maintenance records, and topographical survey data.
• Conducting a site visit to visually assess the current condition and performance of the items being reviewed.
• Completed a geotechnical investigation to assess subsurface conditions by drilling boreholes and conducting field and laboratory review and testing of soil samples.
• Installing and monitoring of various geotechnical instruments.
• Modelled the existing piles under the current geotechnical and operational conditions. Identified thermal consolidation and a main cause of induced settlement and downdrag on piles.
• Identifying piles requiring remediation for the safe structural and operational conditions.
• Completed a laboratory evaluation of a potential bond-breaker remediation strategy through the settling zone. Tested the properties of various potential materials and installation methods.