Effect of Embedment on Dynamic Response of Block Foundation Under Coupled Vibration

Abstract

The dynamic response of a block foundation under machine-induced vibration depends on several parameters such as the shape and size of the foundation, depth of embedment, static load, dynamic excitation frequency and other geological parameters. In this present study, the dynamic response of embedded block foundation of aspect ratio L/B = 1.5 under coupled mode of vibration for different depth of embedment (D = 0, 0.25 and 0.5 m) has been studied. A number of block vibration tests are carried out using a Lazan-type mechanical oscillator under four different eccentric moments (We = 0.2, 0.8, 1.4 and 2.0 Nm) for a static load of 6.6 kN. The frequency amplitude responses of the block foundation for both translational and rotational motion for different embedded condition are also obtained using the half-space theory. The theoretical results are compared with the response obtained from the experimental investigations. The comparison showed encouraging agreement between the experimental test results and that obtained from the analysis. The frequency amplitude response of embedded block foundation indicates that as the embedment depth increases, the resonant amplitude decreases and resonant frequency increases.