饱和地基高填方工程不排水稳定性分析方法研究

对于饱和地基上快速填方，尤其是高填方的稳定性问题，由于超静孔压无法及时消散，有必要进行不排水稳定性分析。我国工程界对于不排水强度指标和分析方法的选用还缺乏广泛的共识，也有因此导致的工程失效案例。为此，该文系统比较了国内外3种不排水稳定性分析方法和相应的强度指标差异，从简单算例入手，到实际工程案例，进行基于有限元极限分析的不排水稳定性计算。计算结果表明对于饱和地基上高填方工程稳定性分析，有必要采用基于Mohr-Coulomb有效应力强度指标的不排水分析方法（Method A），或考虑固结应力作用的不排水强度指标方法（Method B）进行稳定性验算，而利用Mohr-Coulomb总应力强度指标的稳定性分析（Method C）会高估填方工程的稳定性。

UNDRAINED STABILITY ANALYSIS METHODS FOR HIGH EARTH-FILLS ON SATURATED SOILS

For the stability problem of rapid earth-fills on saturated soils,especially for high earth-fills,it is necessary to perform an undrained stability analysis because the excess pore water pressure in foundation soils cannot dissipate in time.There is still a lack of the broad consensus on the selection of undrained strength parameters and analysis methods in Chinses geotechnical engineering society,and there are also engineering failure cases reported.Therefore,this paper systematically compared three undrained stability analysis methods and their strength parameters used worldwide.The finite element limit analysis based on undrained stability calculations was performed for two simple examples and a practical engineering case.The results highlighted that it is necessary to use the undrained analysis method using the Mohr-Coulomb effective stress strength parameters(Method A)or the undrained strength parameters(Method B)for this problem.The conventional stability analysis using the Mohr-Coulomb total stress strength parameters(Method C)mostly overestimates the factor of safety of earth-fills on saturated foundation soils.