ASSESSING THE SUSCEPTIBILITY OF STRUCTURAL COLLAPSE USING SEISMIC REFRACTION METHOD

Seismic refractive survey is a very important geophysical technique used to investigate the characteristics of the subsurface. The rate of building collapse has demanded the acquaintance about the structure of the subsurface especially in area where lands are recovered from water bodies for the aim of building. This paper presents the technique used in determining the thickness of the overburden for quarry prospecting using a geophysical method called as seismic refraction method. Seismic refraction method was used to delineated two distinct layers with the first layer having a weak and incompetent parameter values. The result revealed that the first layer is composed of unconsolidated formation of soft geomaterials and peaty clay that depict the lower values of parameters. This layer is underlain directly by clay, wet sand and sandy clay of soft and weak incompetent consistencies to a depth of 7 m in the subsurface. The second layer was found to have higher parameters than the first layer. The second layer revealed that the geologic formation composed of dry sand and sandy clay of fair to good competent. The geologic formation in the second layer was found to be more competent than the first layer with high allowable capacity and low ultimate failure potential. Geologically, the composition of the first layer is more recent in age of deposition than the second layer, characterized by unconsolidated geologic formation.