Critical acceleration of shallow strip footings

This paper focuses on the assessment of the critical acceleration for soil-foundation systems and the examination of the influences stemming from various relevant parameters. Using a formula recently proposed for the assessment of the seismic bearing capacity of shallow strip foundations, the critical acceleration of the soil-foundation system has been determined by imposing equilibrium between the limit load of the soil-foundation system and the applied load transmitted from the foundation to the ground surface. The proposed solution resulted in an iterative equation that allows for the numerical evaluation of critical acceleration. An extensive parametric analysis has been conducted to explore the effects of many relevant parameters, such as the angle of shear strength of the foundation soil, the value of the surcharge acting aside the footing, the static vertical load transmitted by the foundation, and the direction of the resultant inertial forces acting in the soil and superstructure. The results are presented in design charts for specific sets of relevant parameters, facilitating a quick evaluation of the critical acceleration of the soil-foundation system.