Field testing of geosynthetic-reinforced and column-supported earth platforms constructed on soft soil

Abstract

This paper is focused on the behavior of geosynthetic-reinforced and column-supported (GRCS) earth platforms in soft soil. By analyzing the data of a 15-month long field monitoring project, the bearing behavior and effectiveness of GRCS earth platforms are discussed in detail. It can be found that the soil arching is generated when the filling reaches a certain height. The measured pressure acting on the soil in the center of four piles was smaller than that acting on the soil between two piles. The elongation and the tension of the geogrid located in the soil between piles are both larger than the corresponding values on the pile top. The skin friction of piles is relatively small in the soil layer with low strength and the load transfer of the axial force in those layers is significant; meanwhile, the opposite situation occurs in the soil layer with high strength. The pore water pressure at shallow locations increases slightly with the filling height and is greatly affected by the increasing filling load. The layered settlement is directly proportional to the filling height, and the corresponding amount is relevant to the locations and the properties of specific soil layers. Additionally, the lateral displacement of the embankment increases with greater loading and decreases with increased depth. These suggest that the use of GRCS system can reduce lateral displacements and enhance the stability of an embankment significantly.

Keywords

geosynthetic-reinforced and column-supported (GRCS) earth platforms / soft soil / bearing behavior / settlement and deformation / field testing

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Acknowledgements

The authors gratefully acknowledge the financial support for this work provided by the National Natural Science Foundation of China (Grant Nos. 41172260, 41372292 and 51108393), the National Basic Research Program of China (Grant No. 2008CB425801), and the Specialized Research Fund for the Doctoral Program of Higher Education (Grant No. 20110184110018) as well as the Doctoral Student Innovation Fund of Southwest Jiaotong University. The physical labor and support from Master Han-bing Wang, Xiu-jun Long and Wei Lai are greatly appreciated.

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2014 Higher Education Press and Springer-Verlag Berlin Heidelberg