Evaluating liquefaction induced settlement of shallow foundation on layered soil deposit

Abstract

The occurrence of liquefaction in saturated layered soil deposit underlying the shallow foundation can cause a wide range of problems from settlement to tilting of structures and foundations. It this study in order to evaluate the liquefaction induced settlement of shallow foundation on the ground surface of layered soil deposit, numerical studies have accomplished. The soil deposit involves a continuous saturated fine sand that is sandwiched between two dense continuous sand layers and the whole system had been subjected to a base shaking. The settlement of shallow foundation has been evaluated by considering the influence of relative density (Dr) of middle sand layer. The variation of relative density of middle continuous soil layer was examined by using the finite element method in OpenSEES software. It was observed that the liquefaction has occurred up to the depth of 6 m. In addition, by examining the slope of the settlement-relative density curve, it was found that in continuous fine sand layer for relative densities higher than 60% the effect of this layer on settlement of shallow foundation can be neglected, but for relative densities less than 60% the slope of curve is sharper and as a result, the shallow foundation is experienced higher settlement with 17 cm for Dr = 40% in compare with settlement 10 cm for a uniform soil deposit with Dr = 75%.

Sumatra-fault Earthquake Source Variation for Analysis of Liquefaction in Aceh, Northern Indonesia

“…CSR variable is recommended by NCEER to homogenize various cyclic shear stress variables proposed by each geotechnical research [6,20]. In calculating the CSR value of both sides normalized with the effective vertical stress, the cyclic stress ratio (CSR) is calculated by Eq.…”

“…Fig. (6) shows the distance between each research location and Lampisang faults for peak ground acceleration calculation. The magnitudes of the earthquakes used are Mw 9.3, 9.0, 8.0, and 7.5.…”

“…Liquefaction is among the most extremely complex phenomena that granular materials undergo [3,5]. It is the process by which a loose saturated granular material deteriorates in strength and stiffness under cyclic or static loading as a result of excess pore water pressure generation [2,6,7]. Moreover, liquefaction may occur in loose sandy soils, resulting in decreased soil shear strength as a result of seismic loads during an earthquake [8,10].…”

Study comparison of ground subsidence due to preloading installation of egg tray triangular vertical drains with distance variations on a small laboratory scale

“…Meanwhile, in sandy soil with a large number of pores, the consolidation process will take place immediately. Usually, the length of this consolidation process is determined by the Tv value (time factor) [11,12]. In modeling egg trays as media, vertical channels are placed in a triangular pattern with distances as shown in Figure 2.…”