The Stability Research Of Soft Soil Foundation Combined With Plastic Board Drain In The Cold Region

With the development of national basal construction, building the high-grade highways on the soft soil foundation is increasing, but the stability is being a major challenge. The short construction period in summer, the long downtime in winter, the concentrated loading time, and especially the freezing-thaw behavior, which due to the impact of climate factors, affect the stability of soft soil foundation directly. These make it difficult to build the high-grade highways in northeast regions.So studying the stability of soft soil foundation in cold regions is very important to highway construction in northeast of China.The paper relied on the field monitoring project of soft soil in Si jianfang wetland of the Jixi to Baiquan section project of Jixi to Nehe road in Heilongjiang province. Firstly, the author identified the physical and mechanical characteristics of the soft soil by carrying out laboratory testing study, which provided the parameters for settlement calculation and stability analyses. And analyzed the effect of the freeze-thaw behavior and loading on the soft soil's engineering characteristic from the micro-level by carrying out the freezing-thaw laboratory testing, scanning electron microscopy and energy spectrum analysis.Secondly, the author simulated the field loading on the soft soil foundation using the ABAQUS finite element analyses software, analyzed the stress, strain and the stability of the soft soil foundation combined with the plastic board drain or not. Finally, the author calculated the settlement and analyzed the stability of the soft soil foundation, compared the field monitoring data with the results of the finite element numerical analyses, and estimated the reinforcement effect of the soft soil foundation combined with the plastic board drain. The result showed that the stability of soft soil foundation can be improved effectively combined with the plastic board drain which has a broad prospect in cold areas of Northeast.