Effect of closely spaced footing shape on bearing capacity and settlement in the case of Adama natural soil deposit

Abstract

Foundations are the most important components of any structure and any damage to the foundation results in catastrophic failure of superstructures. The estimation of the bearing capacity and settlement of the soil under foundations depends on shape, dimension, depth of footing and strength of the top soil. In this research, the effect of the shape of closely spaced footing subjected to vertical load were investigated. The objective of this research was to numerically investigate the effect of closely spaced footing shape on bearing capacity and settlement by PLAXIS 3D Connect Edition V20 in the case of the Adama natural soil deposit. The method that used for this research includes a review of related literature, Numerical analysis of bearing capacity and settlement by Mohr-Coulomb model using finite element software. A total of 72 models were investigated on four different soils. A load settlement graph from PLAXIS 3D were used to obtain bearing capacity comparisons for interfered footings with isolated foundations. The result show that circular footing has lower bearing capacity as compared to square, strip and rectangular footing when acted as an isolated in all cases in this study. Isolated rectangular footing rest on soil with medium dense to dense consistency has maximum bearing capacity; However; strip soil rests on loose consistency soil has maximum bearing capacity. Interfered strip footing on medium dense to dense consistency has low bearing capacity. It was concluded that circular footing bearing capacity was lower than square, rectangular and strip when act as an isolated and strip footing has low bearing capacity in adjacent foundation. On average rectangular footing have higher bearing capacity in different soil layer and square footing show intermediate values. It was observed from the results that footing shapes, dimension, spacing ratio S/B and strength of top soil layer were the most parameter that effect bearing capacity and settlement of foundation.