Model Tests on Determining the Effect of Various Geometrical Aspects on Horizontal Impedance Function of Surface Footings

Document Type : Article

Authors

1 Department of Civil Engineering, Sharif University of Technology, Tehran, Iran

2 Department of Civil Engineering, Sharif University of Technology,Tehran, Iran

Abstract

Problems associated with soil-structure interaction have been determined and the Impendence Functions (IFs) evaluated. The aim of this paper is studying horizontal impedance function for surface footings by physical model tests. For this purpose, a cubic steel container was used as a testing environment for two different conditions, a rigid base, and a homogeneous half-space model. The effect of various parameters such as footing shape, embedment ratio, inertia, and dynamic force amplitude was studied in three shapes; rectangular, square, and circle footing. The results indicated that the massless impedance function theory was confirmed at the Dimensionless Frequency (DF) of less than 2.5. Also, in the rigid base model, soil response heavily depends on the vibration frequency, developed by boundary conditions and side walls, in contrast to the half-space model. The rigid base, distribution and reflection of waves in the soil, and dissipation of higher wave energy substantially influenced the dynamic response of soil–foundation system. Additionally, the embedment ratio significantly affected the impedance functions.

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