Bearing Capacity of Pile Foundation Using Different Methods based on SPT measurements for a Soil in Nasiriyah

Pile foundation is an essential issue in most geotechnical projects, which can support different structures such as buildings, storage tanks, and bridges. The bearing capacity of pile foundations can be estimated by using field tests results such as the Standard Penetration Test (SPT) that is performed as part of site investigation because the static load pile test method is expensive, and no analytical solution is available to accurately estimate the bearing capacity of pile foundation in addition to the complex nature of piles embedded in the soil. Many methods are used to estimate the bearing capacity of pile foundations based on SPT; however, the results obtained through performing the bearing capacity based on SPT may give different results depending on the design method. This research used seven empirical equations based on SPT to estimate pile foundation bearing capacity and evaluate the results. The research methodology ruminates the data obtained as part of a site investigation of the water intake project in Nasseriyah, which includes the results of SPT at six boreholes. The types of soil are estimated based on the results of the SPT, where disturbed samples were obtained through performing the test and the soil classification based on the undisturbed samples from the boreholes. The number of blows was corrected before being used in the calculation. The research showed that the method of Shioi and Fukui, for all the six SPTs, gave the maximum bearing capacity. At the same time, the minimum value was obtained by the method proposed by Bazaraa and Kurkur. The bearing capacity estimated by other methods such as Schmeretmann, Decourt, and Meyerhof's equations indicated moderate values located between these computed based on the Shioi and Fukui and Bazaraa and Kurkur's methods. The last method can be considered a conservative method.