Effect of saturation on response of a single pile embedded in saturated sandy soil to vertical vibration

Abstract

The dynamic response of a single pile embedded in dry and saturated sandy soil excited by two opposite rotary machines was considered experimentally. A small-scale physical model was manufactured. It consists of: two small motors supplied with eccentric mass (.012 kg) and eccentric distance (20 mm) representing two opposite rotary machines, aluminium shaft with 20 mm in diameter as pile, and a steel plate with dimensions of (160 × 160 × 20 mm) as a pile cap. The experimental work was achieved taking the following parameters into considerations: pile embedment depth ratio (L/d) and operating frequency of the rotary machines. Twenty-four tests were conducted in medium dense sandy soil with 60% relative density. Half of these tests were performed in dry soil and the other was conducted in saturated soil. In all these tests, the strain along pile’s length and the amplitude of vertical vibration for the pile cap were measured. It was found that the axial strain along the pile becomes frequency-dependent, which means that it increases with increasing the operating frequency, as well as its oscillation increases too. The amplitude of vibration at pile head also be frequency-dependent, it increases with increasing the operating frequency.

Keywords:

• Pile foundation
• amplitude
• vertical vibration
• single pile
• response
• saturated sand