Pressure - Settlement Characteristics of Shallow Foundations using Finite Element Method

Abstract

The present study attempts to represent the behavior of shallow foundations under the effect of eccentric inclined loading in terms of the main criteria of design which are the ultimate bearing capacity, permissible settlement, horizontal displacement and tilt. Due to the square shape of the analysed foundations, three dimensional finite element analysis are used. Elastic-perfectly plastic behavior of soil and rigid of foundations was adopted using Mohr-Coulomb criterion, 15-Node wedge elements were used to model and represent the soil and 5-Node linear elements with three degree of freedom to model and represent the foundations in used program PLAXIS 3D TUNNEL version 1.2.The results of analysis were presented in the form of pressuresettlement, pressure-horizontal displacement and pressure-tilt characteristics. Then the ultimate bearing capacity of the foundations were gotten and compared with (Meyerhof, 1956) and (Saran & Agrawal, 1991), a good agreement was found between them. Using the data obtained from the analysis, non-dimensional correlations have been developed for predicting the values of settlement, horizontal displacement and tilt of eccentrically-obliquely loaded foundations. These relationships can be used by the engineers.

A Comparative Study of Two Soil Models of Tower Settlement under Eccentric Loading Nearby Slope

“…Two cases taken of embedment ratio; first was surface foundation with (Df/B) equal (0), Increasing in embedment depth of foundation caused decreasing in maximum settlement in all models of parametric study at range (32.6 -42.6) %, increase in embedment depth caused overburden pressure which caused increasing in stiffness of soil and thus decreased the settlement. Also, that caused increasing in bearing capacity when the applied loading reached to failure as mentioned in [2].…”

“…Most of studies dealt with a shallow foundation under eccentric or/and inclined loads on flat ground [1,2].…”

“…The aforementioned studies, part of them are experimental work [1,[10][11][12][13], part numerical [2][3][4][5][6], and the other part is experimental and numerical [7][8][9].…”

“…These models include the Hardening Soil Model [7,8] and Mohr-Coulomb Model [2][3][4][5][6]9]. [2] examined models of square foundation subjected to eccentric inclined loading in sandy (loose, medium, and dense) soil, parameters in the study are (depth to width ratio (Df/B), eccentricity to width ratio (e/B), angle of inclined load to vertical, relative density), the results of this study were presented in curves between settlement and pressure, horizontal displacement and pressure, tilt and pressure. When the inclination and eccentricity of load were increased the ultimate bearing, capacity decreased and settlement increased, also the horizontal displacement increased too.…”