Experimental Model for the Machine Foundation Response with Skirt Under Earthquake Loading in Sandy Soil

Abstract

The machine foundation sometimes carries the vibration load developed from the machine run and the seismic load simultaneously. This issue is not covered enough in previous research, especially in the case of laboratory models. Therefore, this paper presents a laboratory model for the response of singly and doubly skirted foundations subjected to seismic loads in sandy soil. The soil was prepared to attain a relative density of 70% in a steel container with a dimension of (50*50*55) cm using the rain technique. Tests were conducted under the dynamic response with a frequency of machine of 30 Hz. A shake table is used; it is exposed to the Halabja earthquake with an intensity of (0.1 g).  In addition, three directions of the machine concerning the axis of an applied load (0ᵒ,45ᵒ,90ᵒ) are selected. The ratio of the skirt depth to the machine foundation width (Ds/B) (single and double skirt) was (0,0.25,0.5). The results showed that high displacement can be obtained when the direction of rotation of the machine’s operation is parallel to the direction of the earthquake, also reduced when the angle is 90ᵒ compared with 0⁰. The best case for reducing lateral and vertical displacement is a double skirt at (Ds/B) =0.5 reached (15% and 13%) comparing to single and without skirt respectively