Experimental study on control of high embankment construction on soft foundation in Xiang-jing Expressway

The construction of 8-meter high embankment on soft foundation in Xiang-jing Expressway in Hubei Province, about 3 meters higher than general one, had the technical difficulty to hasten progress and ensure embankment constructing quality and safety, thus a series of field researches such as kinds of field tests, deformation controlling standards test, preloading treatment test, etc, was done. Firstly, field exploring and tests revealed the existence of 1.0-1.5m-thickness dry crust, sand and gravel strata, and relatively higher strength of vane shear test, which is benefit for accelerating speed of embankment constructing; Secondly, a disposal scheme is selected with combination of prefabricated strip, sand cushion and geogrid; a looser deformation controlling standard which can lead to higher speed of constructing, was successfully tested based on improving condition of drainage in soft foundation; Thirdly, a preloading treatment test was carried out to verify the reliability of prediction of settlement after construction.