TJES: Abdul Kaream K , Fattah M , Khaled Z , .Response of Different Machine Foundation Shapes Resting on Dry Sand to Dynamic Loading. Tikrit Journal of Engineering Sciences 2021; 28(1): 29- 39.
 Al-Homoud, A. S., and Al-Maaitah, O. N. An Experimental Investigation of Vertical Vibration of Model Footings on Sand, Soil Dynamics and Earthquake Engineering, 1996; 15(7): 431-445.  Boumekik, A., Belhadj-Mostefa, S. and Meribout, F. Experimental Analysis of the Dynamic Stress Distribution at the Soil Foundation Interface, Asian Journal of Civil Engineering, Building and Housing, 2010; 11(5): 575-583.  Nagaraj, T. K., and Ullagaddi, P. B. Experimental Study on Load Settlement Behavior of Sand Foundations\\\”, Indian Geotechnical Conference, Bombay, GEO trends, December 16-18, 2010, IGS Mumbai Chapter and IIT Bombay, pp. 807-808.  Al-Shammary W. T. S. Numerical Analysis of Machine Foundation on Saturated Sandy Soil\\\”. M.Sc. Thesis, Building and Construction Engineering Department, University of Technology, Iraq, 2013
Tikrit Journal of Engineering Sciences (2021) 28(1) 29- 39.
Response of Different Machine Foundation Shapes Resting on Dry Sand to Dynamic Loading
In this paper, the effect of footing shape resting on dry sand when subjected to machine dynamic loading is experimentally investigated. A laboratory set-up was prepared to simulate the case at different operating frequencies. Nine models were tested to examine the effects of the combinations of two parameters, including different frequencies of (0.5, 1, and 2 Hz) and different footing shapes (circular, square and rectangular). The tests were conducted under a load amplitude of (0.25 ton) using sand with medium and dense relative densities corresponding to (R.D. = 50% and 80%) having unit weights of (17.04 and 17.96 kN/m3) respectively. A shaft encoder and a vibration meter were used to measure the strain and amplitude displacement, while the stress in the soil at different depths was measured using flexible pressure sensors. It was found that the shape of footing has a considerable influence on the bearing capacity of the supporting soil under dynamic loading. For instance, the strain of dry sand under a circular footing was nearly (41%) higher, the amplitude displacement was nearly (17%) higher, and stress was nearly (12%) higher than square and rectangular footings, under the same conditions