Wak Test To Find Spread Footing Stiffness

Abstract

A method is described to obtain the static stiffness of the soil under a spread footing by using a hammer impact test. In the first part, the analytical background is presented. In the second part, a test setup is described and the associated results are discussed. The test consists of placing two geophones on the footing, hitting the footing with the instrumented hammer, and recording the force time and velocity time signals. The paper shows that the static stiffness obtained in a load test and the stiffness obtained from the impact test by Fourier transform analysis are reasonably close.