The Research Of Settlement Characteristics Of Longyong Expressway Typical Special Soil Embankments

In recent years, the focus of various national infrastructure has began to transfer from east to west, the trend of expressway construction in HuNan province also lies in this. But, different soil has significant differences in different parts of the project application, the experience of other areas about poor soil engineering can’t be directly copied to the western mountainous area expressway construction. Hence, the research about how to determine the stability of the poor soil embankment in the mountains area effectively and evaluate the corresponding treatment measures correctly is necessary.Based on the building LongYong expressway in the Xiangxi Autonomous Prefecture, this paper researched the basic characteristics of two kinds of typical special embankment soil in the process of the construction and their settlement deformation mechanism, analyzed their influence factors more comprehensively, though monitoring the two kinds of typical section, it analyzed the applicability, advantages and disadvantages of monitoring means; according to the measured data, it predicted the embankment settlement in some time though the basic theory of gray theory GM(1,1) model and determined their stability on the basis of the forecast results; combined the results of the gray prediction model with their engineering actual situation, it put up the two types of embankment of different treatment measures; aimed at the defect that the present standard of roadbed stability judgement didn’t consider the differences of some influencing factors for sedimentation rate, just gave the only upper limit value, it imported acceleration methods for judging whether the embankment is stable or not though the acceleration valuence of the lateral horizontal displacement and embankment center settlement, combined the engineering experience with actual situation of the two kinds of typical embankment, gave their own stability decision thresholds, used gray Verhulst model to determine the reliability of thresholds standard to provide certain reference basis for early warning in time.