RABAB HARWEEL INTEGRATED PROJECT - PDO

Rabab Harweel Integrated Project (RHIP) is located in the Harweel Cluster of oil fields in the south of the Sultanate of Oman. The present phase of the project involves many heavy machineries & pipelines which were to be constructed in a problematic foundation soil. Several areas (7 locations) within the project site had existing soil with high gypsum content (6% - 12%) which were susceptible for dissolution and in turn can cause un-predictable settlement. Specifically, the foundation soil with a gypsum content >5% is not acceptable as per the project requirements; from bearing capacity and diferential settelement criteria. Realizing that the conventional ground improvements & deep foundations can consume huge cost, time and require tedious construction activities, the alternative option of ‘ground stabilization with geogrid’ proposed by Maccaferri was agreed by the client.

Understanding the concerns in all aspects, Maccaferri proposed ground stabilization with multiple layers of bi-axial extruded polypropylene geogrid below the heavily loaded structures. Maccaferri proposal was to excavate 2m depth and replace with well compacted granular layers with geogrid (MacGrid EG) layers placed at every 300mm vertical spacing, resulting in a composite of soil with improved bearing capacity & reduced differential settlement that meets the project requirements. Maccaferri was thus subcontracted for design, supply and installation supervision assistance for the ground improvement of 7 different areas, each of 100 meter long x 200 meters wide, where the concrete slabs were going to be constructed to support the heavy machinery.