Performance Requirements for Vibrocompaction on Crushable Calcareous Sands of the UAE and their Verification in Comparison to Silica/Quartz Sands-Technical Paper Upload

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The paper examines vibrocompaction of reclaimed calcareous sands in the UAE, which differ from the silica sands underlying many conventional design methods. UAE reclamation fills commonly contain 50–90% calcium carbonate, including crushable shells and coral fragments. During cone penetration testing (CPT), these particles can break under the cone, producing lower tip-resistance values than comparable silica sands and potentially misrepresenting soil density and treatment performance.<br /><br />The authors describe assessing soil suitability using CPT-based soil behaviour classifications, particle-size distributions and the Massarsch compactability chart. Where vibrocompaction is suitable, project-specific CPT performance criteria are established, with correction factors applied to account for carbonate content and crushability. Quality control includes pre- and post-treatment CPTs, compaction monitoring, settlement surveys, borings and, where appropriate, zone load tests.<br /><br />Case studies from UAE projects—including a power plant, residential island developments and Palm Jumeirah—show how these methods were applied to improve bearing performance, control settlement and reduce liquefaction risk. In the island development example, treatment extended 17–23 m from the working platform to densify only the lower 5–6 m of sand above rockhead, since the upper material was to be excavated for basements. Reported post-treatment CPT results met or exceeded the specified targets.<br /><br />The paper concludes that silica-sand correlations should not be applied unmodified to calcareous reclamation sands. Appropriate correction factors and project-specific verification are essential. The authors recommend calibration-chamber testing on local materials to better establish those factors, improve design confidence and support more efficient, environmentally beneficial ground improvement.

Keywords

vibrocompaction

calcareous sands

UAE reclamation

cone penetration test

carbonates

shell fragments

liquefaction risk

ground improvement

compactability chart

settlement control