Liquefaction Potential of Sandy Soil from Small Laboratory Machine Foundation Model

Abstract

Liquefaction is a phenomenon that occurs during earthquakes, and leads to ground failure. Water-saturated, well sorted, fine grain sands and silts behave as viscous fluid as a result of liquefaction. This behavior of fluids is very different than solids behavior. This paper presents and discusses the results of 54 experimental model tests, all of them were performed on saturated sand under vertical dynamic traffic load using different relative densities (medium and dense), different shapes of footing (square and circular), and different embedment depths (at surface and at depth B) where B is the width of footing. It was concluded that by increasing the relative density of sand, the surface settlement decreases; when sand's relative density increases from 60% to 80%, the reduction of the surface settlement for surface footing condition was about 26 to 72 % at (0.5 ton, 0.5 Hz -2 ton, 1 Hz), and 27 -74 % at (0.5 ton, 0.5 Hz -2 ton, 1 Hz) reduction for embedded footing condition models. Also the embedment of footing in dense sand reduces the settlement more than medium sand, because the dense soil is the stiffest. The amplitude of displacement (Az) decreased at both depths B and 2B, when soil relative density increased, the percentage of reduction in (Az) was about (4-93) % at depth B, and about (37-77) % at depths 2B, when soil relative density increased from (60%) to (80%). Also the displacement amplitude (Az) of the surface square footing is less than that of circular footing at both depths B and 2B.

Liquefaction Potential of Layered Soil Under Vertical Vibration Loads

“…Loose sand contains large voids which can easily compact and increase the settlement. Similar findings by Fattah et al [18] illustrated that the value of foundation settlement increases with increasing load amplitude.…”

“…Bhatia [17] showed the permissible limits of amplitude for different machines for different frequencies and the frequency classified as low-speed machines (100-1500 rpm), medium-speed machines (1500-3000) rpm and high-speed machines (3000-10000) rpm and above. Fattah et al [18] showed that the settlement of a square foundation in medium sand was affected by the embedment.…”

Liquefaction of industrial zone against earthquake loading using laboratory and field measurements

“…The results showed that as load amplitude and frequency were increased, defor mation and liquefaction occurred more frequently and more severely. An experimental work for the liquefaction of sandy soil under the influence of a small machine model has been conducted [3]. The research has concentrated on varying the relative density for the sand, the shape and embedment of the footing model.…”