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

PPT Presentation

Pdf Summary

The presentation examines vibrocompaction of crushable calcareous sands used in UAE reclamation projects, and how its performance should be assessed relative to better-studied silica/quartz sands.<br /><br />UAE reclaimed sands are commonly dredged from the Arabian Gulf and contain shell fragments and high calcium carbonate content, typically 50–90%. Their crushable particles can break under CPT cone pressure, causing measured cone resistance to understate soil density and complicating the use of correlations developed for silica sands. Published studies indicate that shell-related correction factors may range from 1.3 to 2.3, depending on relative density.<br /><br />Vibrocompaction is used to control settlement and reduce liquefaction risk. Typical design requirements include supporting a 150 kPa load on a 3 × 3 m footing, limiting settlement to 25 mm, and meeting seismic design criteria for magnitude 6 earthquakes. Performance is commonly verified using CPT or CPTu data. Requirements vary by project, with examples specifying minimum cone resistance by depth or a minimum improvement relative to pre-treatment tests.<br /><br />The presentation concludes that standard analysis methods and correlations need to be adapted for local calcareous soils, including appropriate correction factors. Calibration-chamber testing on project soils could improve understanding, make tender requirements more transparent, and reduce uncertainty, cost, time, and environmental impact.

Keywords

vibrocompaction

calcareous sands

UAE reclamation

crushable particles

cone resistance

CPTu

liquefaction risk

settlement control

shell fragments

calibration-chamber testing