1g Modelling of Lateral Deformation of 2×2 Short Pile Group Foundations in Liquefied Sand

The earthquake that occurred in Palu-Sulawesi Indonesia in 2018 has caused many problems to infrastructure buildings. One of the impacts of the earthquake was the reduction the level of hardness includes the level of stiffness saturated sandy and condition makes the foundation structure experience greater lateral deformation, which can lead to the collapse of the building above it. This phenomenon is called liquefaction. This article describes the results of laboratory simulations using a one-way shaking table. It aims to obtain the lateral resistance of a group of short pile foundations. The lateral resistance is investigated from the amount of lateral deformation of the pile cap. Laboratory modeling used field and laboratory comparisons at a scale of 1:10. Pile foundations are used in 2×2 pile groups. To obtain the lateral deformation of the pile, Optic Flow is used which is placed on top of the pile cap as high as 30cm. Meanwhile, to obtain the increase in pore water pressure, a PWP sensor was used which was inserted at a certain soil depth of 30cm from the ground surface. The test results show that the lateral deformation of the pile cap due to liquefaction can be observed well. The phenomenon of liquefaction can be observed the excess the pressure of pore water into the soil is caused by loading of seismic. Furthermore, observation results were compared through analysis using the Plaxis 3D program, which showed a good agreement.