Comparison of analytical methods of basal reinforcement design for piled embankments with numerical modelling

Abstract

Geosynthetics are used in many applications that aim to stabilize or reinforce soil containing structures, such as piled embankments. Several design guidelines have emerged (BS8006, CUR, LDC) that include analytical design methods for this type of structures. These methods are in general based on different initial assumptions and formulas, so eventually they produce different results. In many countries there is no official design guideline for geosynthetics for piled embankments, and engineers are left with the difficult task of choosing between existing guidelines of other countries. This article discusses the pros and cons of three analytical methods among the most widely used. This is done by performing a parametric study on hypothetical piled embankment cases. The distance between piles and the embankment height is varied, while the soil and piles parameters are kept unchanged. Numerical modelling with Flac3D software is used for checking if any of the chosen analytical methods would be comparable to the modelling results. It is found that the CUR method is the one with the closest results to the numerical modelling. The other methods were more conservative with differences that reached an order of magnitude. These results seem insightful and a step forward to the design optimization of piled embankments.