Double Non-linear Fluid-soild Coupled Simulating Analysis And Settlement Prediction For Soft Soil Subgrade

Stability and excessive settlement are two important issues encountered in soft ground engineering. Excessive settlement or differential settlement of embankment will deteriorate the road condition., reduce the coziness of the passengers, and even threaten traffic safety. Therefore, strict control of settlement after construction is the technical key in design and construction of soft soil subgrade. Reasonable and accurate prediction of the development in settlement forms the foundation of economically and effectively choosing managing measures and scientifically planning construction schedule. What's more, reasonable arrangement of paving time and effective decrease in settlement after construction are based on such a prediction.Aimed at settlement analysis and prediction of soft soil subgrade, this paper, on the basis of relative projects in Hunan province and Guangdong province and the Double Non-linear (visco-elastic-plastic and large strain) Fluid-solid Coupled Analysis Method, conducted a comprehensive and in-depth study, which included lab tests, field monitoring, theory analysis, numerical simulation and technical application. The issues conducted in this paper are generalized as follows:1. A series of lab tests were performed for the soft clay samples from the west coastal region in Guangdong province, to study the basic physical and mechanical property, permeability characteristic, tress-strain behavior and stress history. In addition, by means of long-term creep tests, rheological properties and parameters of soft clay were determined, and the effect of surcharge precompression on the deformation law of soft clay was obtained.2. Based on sufficient and creditable data from field monitoring, the developing tendency of vertical displacement (surface settlement and deep settlement), horizontal displacement and pore water pressure were analyzed comprehensively, and the effect of construction with 'Applied Folium Step by Step' method on stability and deformation ofembankment on soft soil ground was acquired as well. The results show that the Double Non-linear Fluid-solid Coupled Analysis Method applying to staged filled embankment on soft clay ground with typical rheological characteristic may bring about more reasonable consideration of the effect from time and load on deformation3. The relationship between strength indexes (