Journal of Emerging Trends in Engineering and Applied Sciences: Research Areas

Article Title: Assessment of the Structural Integrity of an In-service School Building at Risk Using Geotechnical Measurement Parameters
by J. O. Ehiorobo and J. O. Okovido

Abstract:
The rate of building collapse and subsequent loss of lives and properties in Nigeria has become a major concern to both government and researchers. This is why it is necessary to carryout integrity assessment anytime there appear to be any sign of distress in major public and private buildings. This paper examines the Structural Integrity of an In-service School Building located in Benin City, Nigeria. Visual inspection of the buildings within the school showed long shear cracks in some of the buildings, particularly Block A. In order to determine if foundation problems were responsible for the cracks, soil samples were collected from different locations around the buildings for laboratory analysis. Dutch Cone Penetrometer Tests (CPT) were also conducted. The soil samples collected were taken to the laboratory for test and analysis. The results of the tests showed that the depositional pattern at the location ranged from clay to sandy soils. Particle size distribution results showed that the clay content vary from between 40 and 60%. The results from the Cone Penetrometer Tests indicate that the soil consolidates from a depth of 4m below ground level. Thus, it can be assumed that the surface of the foundation soils should be at 4m below ground levels. However, the foundation depth of the building is 2.1m below ground floor. This indicates that the foundation of the building is located at 2m above the foundation soils. From the studies, it was observed that the isolated foundation footings are conducting relatively high bearing pressure in a consolidating soil resulting in high differential settlement. This has resulted in series of cracks noticeable particularly in Block A. In order to remedy the situation, a raft foundation slab is proposed to replace the existing ground floor of the building.

Keywords: structural integrity, differential settlement, consolidation, raft foundation.

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