Centrifuge model test on the behavior of geosynthetic-reinforced pile foundations under simulated train loads

• Published in: Acta geotechnica Vol. 17; no. 9; pp. 4131 - 4144
• Main Authors: Xiao, Siqi, Zhou, Jie, Tang, Yiqun
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.09.2022; Springer Nature B.V
• Subjects: Centrifuge model; Centrifuges; Complex Fluids and Microfluidics; Dynamic loads; Engineering; Foundations; Geoengineering; Geosynthetics; Geotechnical Engineering & Applied Earth Sciences; Hydraulics; Load; Loads (forces); Mechanical loading; Model testing; Pile foundations; Piles; Railway construction; Research Paper; Residual stress; Soft and Granular Matter; Soil; Soil dynamics; Soil Science & Conservation; Soil stability; Soil stresses; Soils; Solid Mechanics; Stress distribution; Stress ratio; Tests; Trains; Vibration; Geosynthetic-reinforced pile foundation; Centrifuge model test; Residual stress; Dynamic load; Stress ratio
• ISSN: 1861-1125; 1861-1133
• DOI: 10.1007/s11440-022-01530-8

Geosynthetic-reinforced pile foundations (GRPF) are widely applied for the construction of railways to improve the natural weak foundation formed with soft soil. This paper presents centrifuge model tests to study the possible changes in stress distribution in the GRPF under increasing dynamic loads. A self-designed electromagnetic vibration loading device was developed and effectively validated under similarity scales in centrifuge model tests. One test focuses on the static loading test to compare with the load level in the dynamic loading test. Another two tests study the behavior of GRPF under dynamic loading with the self-developed load device. These two tests reveal the influence of the geosynthetic. The results show the long-term dynamic loading significantly affects the dynamic stress between the piles of the GRPF. A small dynamic load level can benefit the formation of soil arching while large dynamic load level can cause adverse impacts on the GRPF. More dynamic stress is applied to the soft soil between piles with increasing load levels and the dynamic pile–soil stress ratio decreases. Also, the changes of static stress on the pile top indicate the soil arching can collapse under a larger dynamic load level. The residual stress along the pile after dynamic stress indicates that the shaft resistance may change. Moreover, the existence of geosynthetic can help enhance the performance of GRPF by helping re-distribute the stress on pile and soil as well as improving the stability of soil arching.