Construction & Tunnelling

Verifying reported earthworks defects across a residential complex

Al Wakrah, Qatar

Independent satellite measurement confirmed settlement at five locations a contractor had already flagged, and found movement the site records had not.

A large residential building complex had accumulated non-conformance reports covering areas of deep backfill, and the question was whether the reported earthworks defects had produced measurable ground movement.

PS-InSAR over 27 months of ascending and descending C-band acquisitions resolved both vertical and lateral displacement. Five locations showed settlement reaching 36.5 mm in total, with rates of 2.5 mm/year in the critical zones and lateral movement to 8 mm/year.

The settlement areas correlated with the locations the contractor had already identified — an independent confirmation from a measurement that had no knowledge of the site records. The lateral component supported localised instability rather than uniform consolidation, which changes what remediation is appropriate.