Determination of effective parameters in deep foundation settlement

The elements that transport the loads from the building elements to the ground safely and protect the structure by meeting the effects coming from the ground are called foundations.The foundations must maintain structural integrity and should not force the ground on which they are built to be over-stressed.The foundations should be able to carry loads safely upon migration.There are many important parameters to consider when designing the foundations.Two of them are the bearing power and basically the time-dependent sitting value.In some cases, the basic bearing force is insufficient and the building loads must be transmitted to the deeper soils.In this case, pile foundations are constructed and solid layers are reached on the ground. In this thesis, the effects of the ground parameters on the static and dynamic conditions was investigated. In the finite element model, which was formed by using the soil mechanics test parameters which are connected to the drilling data taken from the geotechnical report examined within the scope of the study, the settlements with 17 m and 19 m dimensions were analysed. A total of 54.80 cm settlement was encountered under the spreading foundation and 60 cm diameter drilling pile under the spreading foundation in order to decrease the sitting value was applied according to the square layout plan with a spacing of 1.7 m x 1.7 m and the shaft length was 17 m. In the static case, the seating values are reduced to 1.3 cm below the pile foundation. In the dynamic case, the structure was affected for 10 seconds using Upland earthquake data of 28.02.1990, (Mw 5.4). In this study where the seating behaviour of the drilling piles were examined, the Elasticity Module (E), Cohesion (c), and Friction Angle () values of the ground parameters were changed by 30%, 60% and 90%. In the analysis, it is recommended to make drilling piles under the static foundation in static and dynamic condition. In addition, the most important parameter affecting settlement behaviour was determined as the Elasticity module. Lastly, the sensitivity analysis was performed in the pile foundation system modeled in PLAXIS program. Sensitivity analysis has been developed to find out which input parameters play more important role in complex engineering problems. In the sensitivity analysis, the effect of parameter change on sitting was investigated. As a result of the analysis, it was seen that the most sensitive ground layer was silty clay and the most effective parameter was Elasticity module.