Research On Critical Treatment Technologies Against Soft Clay Foundation Of Bridge Approach Embankment In Seaside Area

The effect of foundation treatment at bridge approach embankment is a matter of the engineering quality and operation safety of highway on deep soft clay foundation in seaside area, which is one of the critical technical guarantees with riding comfort in highways. The research in the thesis was based on the construction of port highway in Yueqing bay. Firstly, based on the experimental data of875natural soft clay from41drilled holes along port road in Yueqing bay, the main physical and mechanical indexes of clay in the region were systematic analyzed; secondly, by using GEOSLOPE and MIDAS finite element software and based on limit equilibrium method and finite element method, stability and settlement regularities of some embankment at bridge approach were further studied. The result may be important quantitative basis for the design of foamed concrete embankment and pile-supported reinforced embankment, and also may be technical guidance for engineering construction. Accordingly, the engineering effect is very evidentThe main work and innovative achievements are as follows:Firstly, based on a large number of experimental data of natural soft clay in Yueqing bay, it was the first time to analyze physical and mechanical indexes of soft clay, the interrelation and distribution regularities of the indexes was proposed. The study’s result might provide engineering construction of Yueqing bay with quantitative analysis. Secondly, based on analyzing sliding mechanism of a low embankment in Yueqing bay, the relation between stability coefficient and height and width of back berm was proposed for the first time by calculating and contrasting stability coefficient under different conditions;Thirdly, the relation between stability coefficient and the value c and φ was obtained by using GEOSLOPE and MIDAS finite element software to research the stability and settlement control technology of bridge approach embankment in the area.Fourthly, the advantages and disadvantages of pile-supported reinforced embankment were systematic summarized. Combined with engineering example, stability and settlement character of pile-supported reinforced embankment were analyzed.Fifthly, the main foundation treatment methods and technology characteristics were systematic analyzed at bridge approach embankment in seaside area, and it was key point to analyze applicability, feasibility and advantages of foamed concrete embankment.Lastly, based on limit equilibrium method, it was the first time to analyze stability of foamed concrete embankment at bridge approach in the thesis; based on finite element model, stability and settlement regularities of foamed concrete embankment in seaside area were analyzed; by comparing transition modes under different conditions, the optimal step width of foamed concrete embankment at bridge approach was proposed, which was’L≥6.0m’, while the height of foamed concrete embankment at bridge approach was6m in seaside area of Yueqing bay.