Study on the behavior of short pile groups on soft soil with sand leveling using a smallscale physical model with schneebeli analog material

Abstract

This paper examines the effectiveness of short piles on soft ground with leveling sand, using a 2D small model. The study focuses on the geology of the Mekong Delta, which consists of a thick layer of soft soil and a layer of leveling sand with a thickness of 2-5m. The use of small and short piles (less than 30x30 cm and 5m or less) is a viable option for low-rise buildings in such conditions. The model replaces the sandy soil with a Schneebeli analog material and the weak clay with EPS foam, while short reinforced concrete piles are replaced by steel bars of the square cross-section. The vertical load tests were conducted on groups of piles, with variable parameters such as pile spacing, s, and the distance from the pile tip to the boundary of two soil layers, H. The results show that when the pile spacing, s, is constant and the distance from the pile tip to the boundary of two soil layers, H, decreases, as well as the deformed soil area under the pile tip. Conversely, when the pile spacing, s, increases, the failure of the soil under the pile tip becomes more localized. The use of a footing increases the bearing capacity of the pile group but also increases the vertical strain of the foam layer in both vertical and horizontal directions. Overall, the study shows that reinforcing soil with short piles significantly improves bearing capacity, increasing it by 2.3 to 3.5 times compared to unreinforced soil.