A computation model for pile-soil stress ratio of geosynthetic-reinforced pile-supported embankments based on soil consolidation settlement

The pile-soil stress ratio (PSSR) is the key to the design and construction of geosynthetic-reinforced pile-supported (GRPS) embankments. However, the computation models for the PSSR which takes account of the effect of consolidation settlement of soil among piles (SAP) is not complete. This paper splits the piles and the SAP into multiple small elements for iterative calculation, according to the principle of the collaborative actions between pile, soil, embankment and reinforcement. The calculation method for pile-soil interaction was improved by Davis' 1D nonlinear consolidation theory, and the hyperbolic load transfer model of pile-soil interface proposed by Wong and Teh. Then, a novel computation model for the PSSR of GRPS embankments was established, under the joint impact of soil arching effect, tension membrane effect and improved pile-soil interaction. Finally, this proposed computation model was proved reasonable by the comparison with tests and other methods, and the effects of key parameters were investigated. The results show that the settlement difference between piles and SAP increased with the degree of consolidation of the SAP and the elapse of time; the PSSR below the reinforcement net (RN) is slightly higher than that above the RN; the PSSRs above and below the RN are both positively correlated with the degree of consolidation and initial bulk compressibility of the SAP. (C) 2020 The Authors. Published by Elsevier B.V. on behalf of Faculty of Engineering, Alexandria University.