Effectiveness of Effective Area Method for Assessing Undrained Capacity of Shallow Rectangular Foundations

Abstract

4This paper investigates the effectiveness of the effective area method (EAM) for assessing the 5 undrained load-carrying capacity of rectangular foundations under combined vertical (V), 6 horizontal (H) and moment loading (M) by comparing with finite-element method (FEM) 7 results. Predicted ultimate limit states under combined loading from the two methods are 8 compared and the equivalent rectangle derived from the EAM is compared with the contact 9 region obtained from the FEM. For one-way eccentricity, good agreement in the V-M capacity 10 is achieved with the two methods despite differences between the effective area and actual 11 contact area. However, V-M capacity for two-way eccentricity obtained from the EAM is 12 significantly smaller than that derived from the FEM, with the discrepancy becoming more 13 pronounced with increasing mobilisation of the vertical capacity. V-H-M failure envelopes 14 established by the EAM also fall significantly inside those determined using FEM. The 15 contributing factors for the discrepancies are explored systematically in the paper. 16 KEYWORDS 17 bearing capacity; footings/foundations; failure; rafts; clays 18Investigation of effectiveness of effective area method for assessing the undrained capacity of shallow rectangular foundations