Vertical Dynamic Analysis of Rigid Strip Foundation on Layered Unsaturated Media

This paper analytically investigates the vertical dynamic response of a rigid strip foundation on layered unsaturated media. Using the triphasic Biot-type model and extended precise integration method, we derive the flexibility coefficient for layered unsaturated media. On this basis, by introducing the Bessel function series of the first kind, the dual integral equations of the mixed boundary value problem in this study are transformed into a set of linear equations. Finally, we obtain explicit expressions for the contact stress and vertical compliance, which are used to evaluate the soil-structure interaction. After the proposed solution is verified, several parameters are presented to study the impacts of the stratification, soil thickness, saturation degree, air-entry value and dimensionless frequency.