T. Tanchaisawat

Numerical Simulation of Geogrid Reinforced Lightweight Geomaterials on Soft Ground Area

A full scale test embankment was constructed on soft Bangkok clay using rubber tire chip-sand mixtures as lightweight geomaterials reinforced with geogrid under working stress conditions. The wall/embankment was constructed with solid modular concrete facing units and rock filled gabion boxes on both sloping sides of the embankment. This paper attempts to simulate the behavior of the full scale test embankment using PLAXIS finite element 2D program. The important considerations for simulation and sensitivity analyses of the behavior of reinforced wall/embankment were the method of applying the embankment loading during the construction process, the assumed soil permeability values during the consolidation process, and the selection of the appropriate models and properties at the interface between the soil and the reinforcement. The effect of settlement predictions are weathered crust thickness and over-consolidation ratio of soft clay because the lightweight backfill loading is much lower compared to conventional backfill. The computed excess pore water pressure is more accurate in shallow depth than deeper depth. The predicted lateral wall movement agreed well with observed field data.