GENERALIZED SOLUTION FOR SEISMIC UPLIFT CAPACITY OF STRIP ANCHORS USING PSEUDO-STATIC APPROACH

Abstract

Generalized solutions for uplift capacity of inclined shallow strip anchors embedded in general c–ϕ soils with inclined slope carrying a uniform surcharge is developed in this paper for seismic condition. The individual effects of unit weight, surcharge and cohesion components on the computation of uplift capacity of anchors are considered. Limit equilibrium method with logspiral failure surface is adopted in the analysis and the effects of seismic forces are considered as pseudo-static forces. The results have been presented in the form of seismic uplift capacity factors as functions of anchor inclination, ground inclination, embedment ratio, soil friction angle and seismic acceleration coefficients both in the horizontal and vertical directions. Both the seismic accelerations change significantly the uplift capacity of anchors. Effect of the vertical seismic acceleration coefficient has been found to always reduce the uplift capacity whereas the effect of horizontal seismic acceleration coefficient has been found to reduce the uplift capacity in most of the cases. Results are presented in graphical and tabular forms. Estimation of error while using the principle of superposition to compute the seismic uplift capacity is also conducted. A comparative study between the present theory and available results in literature shows the merits and requirement of the present analysis.