How deep foundations perform under lateral loads is critical to the safety and stability of infrastructure such as bridges, transmission towers, and offshore structures. In tropical regions like Brazil, lateritic soils, which are characterized by high porosity and collapsible behavior, pose unique challenges to foundation engineering. These soils initially appear strong due to their metastable structure but can rapidly lose strength upon saturation, leading to significant reductions in lateral bearing capacity. Traditional design models often fail to account for this behavior, increasing the risk of structural failure and financial loss. A new paper, “Compacted Soil–Cement Treatment for Collapsible Soils Adjacent to Laterally Top-Loaded Flexible CFA Piles,” fills a critical gap by investigating the lateral performance of continuous flight auger piles in untreated and treated lateritic soils under both dry and flooded conditions.
For a paper in the Journal of Materials in Civil Engineering, researchers Yuri Barbosa, Paulo José Rocha Albuquerque, Gentil Miranda Junior, David de Carvalho, and Marcos Massao Futa evaluated the effectiveness of a low-cost soil-cement treatment of piles to enhance lateral resistance. Their field tests provide a more accurate understanding of soil-structure interaction in lateral situations, enabling engineers to make better decisions that enhance deep foundations’ safety, durability, and resilience. Learn more about these practical, cost-effective solutions for improving foundation performance in problematic soil conditions at https://ascelibrary.org/doi/10.1061/JMCEE7.MTENG-19706. The abstract is below.
Abstract
Lateritic soil usually features an apparently strong structure that can disintegrate upon contact with water and loads. This condition, coupled with high porosity, characterizes the soil in the Campinas region, Brazil. This study investigates the impact of soil–cement treatment on this soil type when adjacent to flexible continuous flight auger (CFA) piles (𝐿/𝐷=30), under both natural and flooded conditions. Four piles were installed, and 10 lateral load tests were conducted covering untreated nonflooded, untreated flooded, treated nonflooded, and treated flooded conditions. Additional analyses were conducted based on a previously published case of this soil treatment with full-displacement piles—FDP (Omega type) performed in the same experimental field. Results showed that soil treatment increased load capacities and horizontal reaction coefficients (𝑛ℎ), and reduced losses under saturated conditions. CFA piles exhibited greater increases in load capacities and 𝑛ℎ under nonflooded conditions, whereas FDP piles experienced lower 𝑛ℎ losses under saturation. Comparison with other pile types tested at the site revealed that achieved load and 𝑛ℎ remained relatively high even under flooding, despite significant percentage reductions.
See how you can apply these findings immediately to enhance your foundation design in the ASCE Library: https://ascelibrary.org/doi/10.1061/JMCEE7.MTENG-19706.
