Undrained seismic bearing capacity of surface strip foundations on cohesive slopes

In recent years, some comprehensive research studies have focused on the issue of the undrained seismic bearing capacity in the field of the foundation engineering. However, there is no complete and sufficient solution for calculating the magnitude of the undrained seismic bearing capacity. In this study, a practical and effective method was presented for the calculation of undrained seismic bearing capacity factor for surficial strip foundations on cohesive slopes. Using Finite Element Method, numerous analyses were performed in PLAXIS to investigate the influence of different soil and geometrical parameters on undrained seismic bearing capacity factor. In the analyses, the model was solved as a pseudo-static problem. The considered model has several variables which are possible to influence the numerical results. These variables are the distance between the footing and the slope edge, slope angle, crest height, soil properties and horizontal seismic acceleration coefficient. Using undrained Mohr-Coulomb type of constitutive model in PLAXIS, four different undrained material sets which have different consistency values were defined. Utilizing PLAXIS numerical results obtained; design charts and necessary equations were developed. In addition, charts were developed for identifying the limits of permissible states for the seismic bearing capacity problem of surficial strip foundations.