Experience in modelling the behavior of foundations on a liquefiable base using PM4Silt model.

One of the many construction problems at present is that large areas are composed of weak water-saturated soils and have complex behavior under seismic influences. During an earthquake, non-standard processes can occur at the base, including soil liquefaction, which negatively affects the dual work in the "base - foundation - structure" system. In such conditions, pile foundations are widely used due to several advantages. However, their behavior during the liquefaction of the surrounding soil has not yet been adequately studied. It is known that the reinforcement of the base with vertical elements, such as piles, is one of the most effective ways to increase the strength and deformation properties of weak soils. Reinforced massifs are also often used in seismic regions. However, the process is still poorly understood in the case of soil liquefaction due to the passage of seismic waves through the ground. Using the modern soil model - PM4Silt, which was developed in 2018, a geotechnical task is set in this paper, in which the behavior of the "base - foundation - structure" system during liquefaction of the upper soil layer, and also for two variants of foundations is considered. The foundation in the first variant is a classic pile foundation. In the second variant, a slab foundation is used on a base reinforced with vertical piles, the characteristics of which coincide with the piles in the first variant. The main goals of the calculations were to get the difference in the resulting deformations of the base, internal forces in the structures and understand whether the use of different types of foundations contributes to the picture of the liquefaction of the upper layer. The results show significant differences between the two foundation variants when using the PM4Silt model, as well as the dependence of the position of the soil liquefaction points on external factors. [ABSTRACT FROM AUTHOR]