Application of dynamic compaction in Port of Ras Laffan Expansion Project

Abstract

Dynamic Compaction (DC) has recently been used to improve 175,000 m2 of hydraulically reclaimed land using carbonate sand and gravel and with a variable thickness of up to 16 m as part of Port of Ras Laffan expansion in Qatar. Acceptance criterion for the project was based on a minimum relative density value with CPT verification or alternatively performance criteria with Pressuremeter Testing. Due to the required depth of treatment, the innovative MARS technology was also used to drop a 35 ton pounder in free fall. Calculations based on post improvement test results clearly suggested that implementation of acceptance criteria based on a project's specific technical requirements is able to achieve project goals at a more affordable cost and in a shorter period than using specified minimum test values. During the works pockets of fine soils were identified in the treatment area. At the end of the works in addition to the anticipated field tests, a full scale load zone test was carried out at a location within the sensitive skid beams area where it was understood that the fine soil layer was thickest. Settlement monitoring indicated that short and long term settlements of the skids will be within the project specifications.