A study on lattice frame reinforced system to reduce settlement of coastal embankments

This paper presents a study on the behaviour of the lattice frame reinforced (LFR) system under rock embankments. The LFR system is used to reduce the rate of rock embankment settlement. It contains two main components, a mortar injected polyester tube lattice frame (LFR mortar tube) and an underlaying polyester sheet (LFR sheet). Two experimental embankments with the LFR system were constructed for this study. The actual measured soil settlements under the embankments were monitored for a period of 30 months. This paper aims to explain the mechanism of the LFR system by applying finite element (FE) simulations by LS-DYNA and field measurements. Also, the modelling approach used to model the behaviour of the LFR mortar tube was proposed by incorporating tension-stiffening effects into the constitutive law of the LFR tube. The field measurement and analysis results showed that the LFR system could effectively reduce the long-term soil settlement caused by the embankment. FE analysis showed that LFR mortar tubes behaved as tensile members and there was a significant effect of the grid spacing of the LFR mortar tube on settlement reduction. The field measurement results could be satisfactorily simulated using FE analysis by considering the tension-stiffening behaviour.