Investigation on relationship of geogrid strain and settlement in the GRPS embankment under cyclic loading

Abstract

Geosynthetic-reinforced pile-supported (GRPS) embankments provide an effective solution for mitigating subgrade settlement and enhancing service performance. This study presents a series of physical model tests aimed at gaining a comprehensive understanding of the mechanical behavior of geogrids in GRPS embankments. Effects of loading cycles, loading frequency, geogrid layer number, and pile type on geogrid strain and settlement were investigated. An empirical formula was introduced to evaluate the impact of these factors on the relationship between geogrid strain and settlement. The results demonstrate that both geogrid strain and settlement increase with loading cycles and loading frequency, while longer piles effectively reduce settlement. GRPS embankments with two geogrid layers exhibited smaller geogrid strain and settlement compared to those with a single layer. A power function incorporating the normalized geogrid strain increment ratio and settlement was developed to predict the geogrid strain variations under cyclic loading, with significant influence from the aforementioned factors. Furthermore, an application of the EBGEO method, modified to account for cyclic loadings, is proposed, which introduces a load parameter to account for the number of loading cycles. The results obtained using this modified method closely align with measured values, providing a more accurate estimation of geogrid strain development under cyclic loading.