Abstract: It is widely concerned about the issue of intolerant settlement and stability of high embankments constructed in mountain areas with soft clay. At present, there are very limited reports on the field measurements of high fill embankment supported by the prestressed high-strength concrete(PHC) pile. A series of field observation based on a project case has been carried out to examine the performance of a highway embankment (30 m high) supported by PHC pile over soft foundation. Measured data includes load acting on the head of the pile, settlement, excess pore water pressure and horizontal displacement. The results show that the effect of the soil lagging the adjacent pile in the development of vertical displacement is observed, and post-construction settlement of the soil during the period of half a year increased approximately at a settlement rate of 1/4 during the filling period. It is also found that the maximum horizontal displacement related to the width of front slope path does not always occurred near the foot of the embankment, where soil may flow around the piles, and even the bending or deflection failure of the piles. The research work is expected to provide the valuable reference for the further case studies on high embankment construction.

Key words: high embankment, prestressed high-strength concrete (PHC)pile, soft foundation, field observation