Assessment and retrofitting of deteriorated light structure founded on expansive soil

ABSTRACT

Structure damages are becoming very common when constructed in arid and semi-arid areas on problematic soil. This may be attributed to the inadequate geotechnical investigation prior to construction. The problem is most effective in case of light weight structures constructed on arid problematic soils without any special considerations for these types of soil, and the problems start to arise with the entrance of structure to the service and the seepage of water to the founded soil. In this paper, a case study for a villa in a gated compound; just after 6 months from construction, the walls of this light structure suffered severe cracks. A careful inspection and geotechnical site investigation showed that the structure’s foundations have been subjected to differential movement at its western part, due to percolation of water into bed of high potential swelling soil. In addition, the stiffness of the basement columns was very low. Some consultants recommended to demolish the villa, nevertheless, an intensive structural analysis taking into consideration conditions of the concrete skeleton had led to select proper structure’s remedial measurements to stop the heave and shrinkage problems, and to improve the structure’s stiffness. The retrofitting measures included removing the expansive clayey layer which was of limited thickness and area; modifying the foundation system, and replacing the basement columns with inadequate strength with new ones. The measurements of the monitoring process during and after finishing repair processes had shown no movements, which reflects the efficiency of implemented retrofitting techniques.

KEYWORDS:

• Deterioration
• expansive soil
• repair techniques
• foundation damage
• differntial movement
• soil-structure-interaction

Disclosure statement

No potential conflict of interest was reported by the author(s).