JZUS - Journal of Zhejiang University SCIENCE

Journal of Zhejiang University SCIENCE A 2012 Vol.13 No.7 P.506-518

Theoretical elastoplastic analysis for foundations with geosynthetic-encased columns

Author(s): Yuan-yu Duan, Yi-ping Zhang, Dave Chan, Ya-nan Yu
Affiliation(s): College of Civil Engineering and Architecture, Zhejiang University, Hangzhou 310058, China; more
Corresponding email(s): zhangyiping@zju.edu.cn
Key Words: Geosynthetic-encased columns (GECs), Equal vertical strain, Elastoplastic deformation, Analytical procedure

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Abstract: As a new technique in ground improvement, geosynthetic-encased columns (GECs) have promising applications in soft soil foundation. By assuming yielding occurs in the columns while the surrounding soil and the geosynthetic remain elastic, an elastoplastic analytical procedure for foundations improved by GECs is proposed. The radial stresses that the geosynthetic provides and the elastoplastic deformations of the foundation resting on a rigid base are derived. A comparison with finite element analysis shows that the proposed method is effective and can provide a reasonable prediction of a GEC’s deformation. Subsequent parametric analysis indicates that higher geosynthetic stiffness leads to better performance of the composite foundation. The optimum length of encasement is related to the load acting on the foundation and the permissible vertical and radial displacements of the column. Moreover, as the dilation angle of the column increases, the settlement decreases, especially under high loading. The influence of the encasement is more significant in soils with smaller elastic modulus.

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