Prediction versus performance on lateral displacements in soft Bangkok clay under embankment loading

The embankment of 1.8 to 2.2 m. high has been constructed on very soft Bangkok clay parallel to the existing Bang Na-Bang Prakong Highway. The Bangkok subsoils consist of about 20 m thick very soft to medium grey clay and the strength is in the order of 0.8 to 2.5 t/m 2 . Geotechnical instruments, such as inclinometers,settlement plates, and piezometers were installed to measure the lateral and vertical soil displacement. The results indicate that the ratio between maximum lateral and vertical displacement (Rhv) have a good relationship with embankment slope stability safety factor and with the maximum final shear stress ratio (fmax). The prediction of Rhv-value based on the finite element method with undrained linear elastic soil model agrees well with measurement only when the maximum final shear stress ratio is larger than 1.0 or local yield failure is encountered.