A Zhajiasu Highway Roadbed Construction In Soft Soil Settlement Characteristics Of Study

The most effective way to solve the problem of settlement for the embankment in soft clay rationally is that, by building trial section or doing some field test on the entity engineering project, take use of the experiment observational data to identify the validity of the theory and calculation method, which can be further consummated after the test. Based on the upper principle, according to the settlement monitoring program of Jia-Su Expressway in Zhejiang Province, this paper adopted the methods of theoretical calculating, field data predicting and finite element simulating, to analytic study the characters of the settlement for the soft clay embankment in K16+250 section (the third typical section). And the following main research findings are acquired:1. The elastic theory formulas are used to calculate the instant settlement and the main consolidation settlement are analyzed in which compression modulus method , e—p curve method and e—logp curve method are adopted. When being lack of stress history data, the compression modulus method and e—p curve method are suggested.2 . After getting the measured load-time-settlement(P-T-S) curve in the third typical section, the hyperboia method , exponential curve matching method, settlement speed method, Asaoka method are used to predict the total settlement. The hyperboia method and exponential curve matching method are of higher accuracy in the upper project.3. Research on the consolidation in foundation improved by sand well. Base on the Terzaghi one-dimensional consolidation theory, the axial symmetry consolidation theory in the foundation improved by sand well are built, also the degree of consolidation influenced by the multi-stage preloading are analyzed. By using the measured load-settlement curve, the parametersα,βare calculated , and it has greatly predigested the calculation of the consolidation degree and total consolidation settlement in foundation improved by sand well, also reduced the error brought by the choice of parameters and have a guiding significance for the construction.4. The large finite element calculation software(ADINA) is used to build model for the third section, in which the Cam-Clay model is choosed to analyze the settlement, and compare settlement with pore water pressure dissipation. The settlement alteration rules along with the pore water pressure dissipation or horizontal distance, the pore water pressure alteration rules along with time are basically coherent with the measured value, which has showed the rules for the deformation of foundation improved by sand well and pore water pressure dissipation.5. The calculating results of settlement fit well with the measured value ,in which the calculating method of foundation average permeability coefficient that brought forward in this paper are adopted. The calculating method of foundation average permeability coefficient is proved credible.