Consideration on Limit Load Space of Footing on Various Soils Under Eccentric Vertical Load

Abstract

This study estimated on the bearing capacity of a footing against eccentric vertical load placed on two types of soil, namely, sandy soil and clayey soil, using the rigid finite element method (RPFEM). For the sandy soil, the study newly introduces an interface element into the footing-soil system to properly evaluate the interaction between the footing and the soil, which greatly affects the failure mechanism of the footing-soil system. For the clayey soil, the study improves the analysis procedure by introducing a zero-tension analysis into the footing-soil system. Two friction conditions of the footing surface were considered which are a perfectly rough and smooth conditions. The effect of the eccentric vertical load on the normal stress distribution at the footing base and the failure envelope in V-M plane is thoroughly investigated. According to the obtained results, it can be seen that changes in the normal stress distribution reflecting to both the eccentricity length and the friction condition were observed. Finally, new equations were proposed to determine the normalized V/V_ult and the failure envelopes of both sand and clay.