# Numerical analysis of mechanical factors influencing the bearing capacity of piled raft foundation on saturated overconsolidated clay

• Kazuhiro Kaneda
Conference paper
Part of the Lecture Notes in Civil Engineering book series (LNCE, volume 62)

## Abstract

Piled raft foundation is used to reduce the settlement of soft clay by using the friction between the pile and soil. Recently, a numerical approach (FEM) was adopted in a study to clarify the mechanism of the bearing capacity of piled raft foundation. In addition, the finite deformation theory and the subloading model based on the unconventional plasticity theory are introduced. Under a small load, the distinct difference between the infinitesimal and finite deformation analyses cannot be observed, but when the deformation is large, the difference is remarkable. This is because the influence of geometric nonlinearity becomes large. The behavior of over-consolidated soil can be expressed appropriately using the subloading model. When the load is applied at the piled raft foundation, compression and shear behavior are observed around the element at the tip of the pile. Finally, the possibility of deformation prediction using FEM is demonstrated.

## Keywords

numerical simulation piled raft foundation settlement bearing capacity

## References

1. Asaoka, A., Nakano, M., and Noda, T. (1994). Soilwater coupled behavior of saturated clay near/ at critical state, Soils and Foundations, Vol. 34, No. 1, pp. 91–105.
2. Asaoka, A., Nakano, M., and Noda, T. (1997). Soilwater coupled behavior of heavily overconsolidated clay near/at critical state, Soils and Foundations, Vol. 37, No. 1, pp 12–28.
3. Asaoka, A., Nakano, M., and Noda, T. (2000). Superloading yield surface concept for highly structured soil behavior, Soils and Foundations, Vol. 40, No. 2, pp 99–110.
4. Asaoka, A., Nakano, M., Noda, T., and Kaneda, K. (2000). Delayed compression/consolidation of natural caly due to degradation of soil structure, Soils and Foundations, Vol. 40, No. 3, pp 75–85.
5. Bishop, A. W., and Henkel, D. J. (1962). The Triaxial Test. Edward Arnold, London.Google Scholar
6. Hashiguchi, K. (1989). Subloading surface model in unconventional plasticity, International Journal of Solids and Structures, Vol. 25, No. 8, pp 917–945.
7. Kaneda K, Honda T, Shigeno Y., and Hamada J. (2013). Numerical Simulation of the Load Tests on Bearing Capacity of Piled Raft Foundations. Proceedings of the 18th International Conference on Soil Mechanics and Geotechnical Engineering, Paris, France, pp 2771–2774.Google Scholar
8. Kaneda K, Shigeno Y, Honda T., and Tanikawa T. (2012). Numerical Simulation of Load Tests on the Bearing Capacity of Piled Raft Foundations. Testing and Design Methods for Deep Foundations, IS-Kanazawa, Japan, pp. 491–496.Google Scholar
9. Sahara M., Akino N., and Tominaga K. (2002). A method of immediate settlement analysis of piled raft foundation based on load transfer method, J. Struct. Constr. Eng., AIJ, No. 561, pp 111–118. (In Japanese).
10. Wakai A., Tamura M., and Okano T. (2008). Fundamental study on prediction of long-term settlement of house based on three dimensional finite element method, J. Struct. Constr. Eng., AIJ, Vol. 73, No. 626, pp 567–574. (In Japanese).