Mohammad Mehdi Pardsouie - Ph.D. candidate, Department of geotechnical engineering, Estahban Branch, Islamic Azad University, Estahban, Iran.
Seyed Mohammad Zomorodian - Associate professor, Department of Water Engineering, Faculty of Agriculture, Shiraz University, Shiraz, Iran.
Mehdi Mokhberi - Associate professor, Department of geotechnical engineering, Estahban Branch, Islamic Azad University, Estahban, Iran.
Mohammad Hadi Pardsouie - M.Sc. student, Department of geotechnical engineering, Estahban Branch, Islamic Azad University, Estahban, Iran.

Three trial embankments as TS۱, TS۲, and TS۳ that were built for the investigation of a soil treatment project in Bangkok were modeled and verified based on the reported data. To clarify the importance of integration of the hydraulic modifier function vs stress, in the verified models, the modifier functions were omitted and the FEM models were run in the absence of the function. It was shown that after the omission of the hydraulic modifier, the results were overestimated especially for the TS۱ and TS۲, which had smaller PVDs (prefabricated vertical drains) distance. For the TS۱ embankment, the settlement increased from ۰.۷۸ m to ۰.۸۷ m in ۲۱۰ days. In ۳۶۵ days, the settlement increased from ۱.۲۷ m to ۱.۴۴ m. For the TS۲ embankment, the settlement increased from ۰.۹۳ m to ۱.۶۷ m in ۲۳۰ days. In ۴۱۰ days, the settlement increased from ۱.۳۶ m to ۲.۲۷ m. For the TS۳ embankment, the settlement increased from ۱.۱۵ m to ۱.۷۹ m in ۲۳۰ days. In ۴۱۰ days, the settlement increased from ۱.۵۲ m to ۲.۲۴ m. The inclusion of the hydraulic function that calibrates the model for every step of loading is essential in the modelling such problems. For the design phase, this function should be calculated from lab tests, preferably undisturbed samples that were bored from the site, and the resultant function be used as an inseparable part of modeling and calculations.

PVD, Consolidation, Soil treatment, Hydraulic modifier, surcharge