REMEDIAL WORKS TO ARREST THE DIFFERENTIAL SETTLEMENT OF SABIC BUILDING FOUNDATIONS-Paper

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The East Wing of the SABIC Building in Al-Jubail, Saudi Arabia, experienced continuing movement at its expansion joint with the main building. The joint had opened by approximately 150 mm at roof level. Investigations considered thermal movement, ground spreading, soil collapse, and other factors; structural analysis identified excessive differential settlement as the primary cause. Estimated soil pressure beneath the raft was at least twice the allowable bearing capacity stated in site reports.<br /><br />A comprehensive assessment included inspections, structural analysis, and monitoring of cracks and building tilt. The team designed an external micropile support system to stabilize the East Wing without disrupting the building’s interior. A pile load test established a service capacity of approximately 500 kN, with settlement limited to about 4 mm.<br /><br />The remedial works comprised 103 pressure-grouted micropiles installed beneath the raft. Each pile was 25.5 m long, with a 225 mm grout body and a hollow steel reinforcement bar. Three-dimensional nonlinear analysis indicated that the system would support the East Wing and reduce raft soil pressure to the recommended allowable limit of 100 kPa. Checks also confirmed that the existing raft reinforcement and thickness were adequate.<br /><br />The case highlights the importance of verifying geotechnical design parameters and retesting soil after improvement. The micropile system was found suitable to arrest further settlement and stabilize the East Wing.

Keywords

SABIC Building

East Wing

Al-Jubail

expansion joint

differential settlement

micropiles

raft foundation

soil bearing capacity

structural stabilization

geotechnical assessment