NUMERICAL STUDY OF KINEMATIC SOIL FOUNDATION INTERACTION AT THE LIQUIFIED SOIL INTERFACE DUE TO EARTHQUAKE

• Main Author: Dwi Amboro, Bayu
• Format: Theses
• Language: Indonesia
• Subjects: Teknik sipil
• Online Access: https://digilib.itb.ac.id/gdl/view/46062
• Institution: Institut Teknologi Bandung

Foundation design so far only considers the effect of inertia and ignores the kinematic effect. Even though the maximum response that occurs on the foundation can be caused by the inertia interaction or kinematic interaction. In this study, the evaluation of the soil-foundation kinematic response due to earthquake loads was carried out by the three-dimensional (3D) finite element method (FEM) using PLAXIS 3D. The modeling technique is validated by comparing the results of soil responses and pile foundations from centrifugal tests and finite different methods (FDM). This parametric study was carried out using loose sand soil as deep as 15 m with potential liquefaction and stiff clay underneath as deep as 15 m. The top layer is loose sand which varies in depth to the top 5 m. The constitutive model used is UBC Sand. Evaluation of moment and shear responses that occur at the two-layer interface is evaluated based on the effect of increasing peak ground acceleration (PGA) value, the effect of relative density (Dr), the effect of predominant differences in earthquake periods, the effect of single piles and pile groups, and the effect of liquefaction on the increase the value of relative density (Dr). The representation of the upper structure is modeled as axial and lateral loads acting on the pile cap according to the capacity of the single pile foundation static clearance. Based on the analysis results, the maximum moment and shear forces occur around the interface of two layers of soil. The increase in moment and shear values is directly proportional to the increase in PGA values and inversely proportional to the increase in the value of Dr, predominant period, and pole configuration. While the increase in the value of Dr is inversely proportional to the ru value and is directly proportional to the increase in pole configuration.