In recent decades, both above-ground and underground storeys of buildings have increased substantially at high-value urban locations. With urban development, extensive underground utility infrastructure, subway tunnels, etc., are also being constructed. High or fluctuating groundwater levels can generate uplift forces on enclosed underground structures, yet engineers often overlook this excessive buoyancy hazard when precautions are insufficient. Structures damaged by buoyancy require a thorough investigation to assess rehabilitation feasibility or to determine whether removal is necessary due to technical or economic constraints. This article presents a methodology for evaluating buoyancy-affected structures and developing rehabilitation solutions, illustrated through a case study. An inadequate design and execution of a single detail of an underground garage caused its sudden uplift. Based on site examination, review of design documentation, and uplift stability verification, a controlled lowering and rehabilitation procedure was successfully developed and implemented
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