CFG Pile Composite Foundation: Its Engineering Applications and Research Advances

Matlan

Advances in Civil Engineering

et al. 2021

The focus of this study was to investigate the effect of loess soil treated with lime on the lateral-seepage response. Three groups of box experiments were carried out to study the lateral-seepage effect under different types of loess-lime structures. Automated testing systems were designed to perform experiments and collect data. Additionally, numerical analysis of lateral-seepage impact and embankment settlement was performed. Finally, moisture content and settlement were monitored to quantify lateral-seepage effect results under corresponding loess-lime treatment. Results showed that loess-lime compaction piles and diaphragm wall structures could effectively prevent lateral seepage, and the latter was better. The simulated results are similar to the measured values of the box experiment, which indicates the accuracy of the simulation analysis and further supports the experimental results of this study.

“…e standard methods used to eliminate collapsibility include tamping [9], exchange-fill [10], cement mixing pile [11], CFG pile [12], and building seepage prevention structure.…”

Section: Introductionmentioning

confidence: 99%

Experimental and Numerical Analysis Study on Loess‐Lime Structures Used for Lateral Antiseepage in Deep Collapsible Ground Embankment

Matlan

Advances in Civil Engineering

et al. 2021

Studia Geotechnica Et Mechanica

“…[1] Crowned with interposed load transfer platform (LTP) of an appropriate material under the raft, cement-fly ash-gravel (CFG) piles are used as column-type rigid inclusions to reinforce shallow weak soils and receive the upper imposed load indirectly. Recently, Uge and Guo [2] have made a succinct overview on their area of application in engineering practice. It is revealed that due to the deformability characteristics of the LTP layer, negative side friction (NSF) develops on the upper 15%-50% of the pile length, where settlement of the shallow soil becomes greater than that of the pile owing to the pile head pricking into the LTP layer.…”

Section: Introductionmentioning

confidence: 99%

Numerical study on stress paths in grounds reinforced with long and short CFG piles during adjacent rigid retaining wall movement

Uge

Guo

Liu

2022

Self Cite

Ensuring the safety of existing structures is an important issue when planning and executing adjacent new foundation pit excavations. Hence, understanding the stress state conditions experienced by the soil element behind a retaining wall at a given location during different excavation stages has been a key observational modelling aspect of the performance of excavations. By establishing and carrying out sophisticated soil–structure interaction analyses, stress paths render clarity on soil deformation mechanism. On the other hand, column-type soft ground treatment has recently got exceeding attention and practical implementation. So, the soil stress–strain response to excavation-induced disturbances needs to be known as well. To this end, this paper discusses the stress change and redistribution phenomena in a treated ground based on 3D numerical analyses. The simulation was verified against results from a 1 g indoor experimental test conducted on composite foundation reinforced with long and short cement–fly ash–gravel (CFG) pile adjacent to a moving rigid retaining wall. It was observed that the stress path for each monitoring point in the shallow depth undergoes a process of stress unloading at various dropping amounts of principal stress components in a complex manner. The closer the soil element is to the wall, the more it experiences a change in principal stress components as the wall movement progresses; also, the induced stress disturbance weakens significantly as the observation point becomes farther away from the wall. Accordingly, the overall vertical load-sharing percentage of the upper soil reduces proportionally.

Num Anal Meth Geomechanics

“…cement-fly ash-gravel). 9,10 Because of the excellent drainage efficiency of loose material pile, it can facilitate the drainage of the excess pore water pressure within the soil, and thus accelerates the consolidation process. The consolidation theory for the loose material pile foundation has been well developed since Barron 1 solved the analytical solutions for the consolidation of fine-grained soil by drain wells.…”

Section: Introductionmentioning

confidence: 99%

Analytical solution for consolidation of sand‐filled nodular pile (SFNP) foundation and its engineering application

Sun

Naggar

et al. 2022

The sand-filled nodular pile (SFNP) foundation is newly proposed to improve the bearing capacity and accelerate consolidation settlement of foundations installed in soft clay soil. By filling sand while driving the nodular pile into the soft clay soil, the SFNP foundation provides an extra drainage path with the aid of the nodular segment, while maintaining the high modulus reinforcement body at the core of the composite foundation. The performance of the SFNP foundation is greatly influenced by its consolidation behaviour. This study develops a generalized model for the SFNP foundation, and a closed-form solution is then established considering the smear and well resistance effects. The developed model and the associated analytical solution are employed to investigate the consolidation rate and load distribution of the SFNP foundation. Finally, the analytical solution is utilized to evaluate the performance of SFNP foundation for an expressway project located in Zhejiang, China. The predicted dissipation of the excess pore water pressure employing the developed analytical solution agreed well with measured response from the field test, which further confirmed the advantages of the SFNP foundation and the reliability of the developed solution.