ABSTRACT
‘Monitoring Closeout Reports’ are typically prepared before decommissioning monitoring equipment not needed during the operation phase of an underground structure. Addressing inconsistent or spurious records is crucial to ensure safety assurance closure. This paper discusses a case where an inclinometer installed in a diaphragm wall panel of a dive structure showed a much larger deflection than previous readings before decommissioning. This was not addressed in the project’s Monitoring Closeout Report. Nearly two years later, a structural back-analysis study was needed to close the ‘Geotechnical and Structural Safety Assurance Report’. The study included an imposed displacement case as well as with external loads and internal forces due to thermal shrinkage to assess the panel’s response. The findings confirmed that the D-Wall panel remains structurally safe based on its as-built characteristics and determined the final inclinometer reading was an outlier, enabling closure of the issue to the owner’s satisfaction.
