Investigation of air foam mixed stabilized soil embankment after 12 years of service

Abstract

Large differential settlement between highway embankment and bridge structure causesproblem in the lower Chao Phraya river basin because of the presence of highly compressible
soft clay layer in these areas. Furthermore, it also affects to the comfort of road user. Therefore, the Bureau of Road Research and Development, Department of highways (DOH), cooperated with the Public Work Research Institute (PWRI) of Japan to implement the soft ground improvement technique using
Air Foam Mixed Stabilized Soil (AMS). The PWRI provided the technical supports of this technology. A full-scale test section was constructed on the highway No.35 (Rama II) at the kilometer post of 72+712.5 to 72+845 RT (Inbound) in Samut Songkhram province. The objectiveof this paper is to present the effectiveness of AMS embankment after 12 years of service. Considering factors included road inventory, traffic information, groundwater level, surface elevation, and laboratory test of field cored AMS samples. Results indicated that the AMS embankment section exhibited less settlement (~50 percent) comparing to the conventional fill embankment. In addition, the laboratory results also suggested that the AMS samples remained in a good condition although they were inundated due to the high groundwater table. The long-term strength and durability also met the design specifications.