Effect of Embedment Depth on Cyclic Behavior of Tank Footings on Dry Sand

Abstract

Fuel tank footings are usually subjected to cyclic loads caused by filling and emptying of these tanks. In addition, in a multitude of geotechnical applications, soils are subjected to cyclic loading. Besides vehicle and traffic loads, cyclic loads also play an important role in pile driving processes and during the dimensioning of foundations for offshore wind craft plants. Research on the cyclic vertical loading problem for sand is particularly scarce, and most has been in commercial confidence. This paper is conducted to study the experimental behavior of dry sandy soil under foundations subjected to vertical cyclic compression load. A total of sixty-three models have been tested to study the behavior of shallow footings under cyclic load of different rates. A new compression machine was manufactured to apply both monotonic and cyclic loading. Three relative densities of sand, two footing shapes, three depths of foundation embedment, and three rates of loading were tried. It was concluded that with more depth of the footing (D_f increasing), the soil settlement decreases. In general, when other factors are remaining constant, the bearing capacity of the soil goes on increasing when the depth or width of the foundation increases. The total settlement of a footing continues to increase during the time of the load and reaches a maximum value at the end of dwell time. During the decay period of the load, the footing rebounds to some degree.