中文摘要：

Biot固结理论的流固耦和机理较为严密，但应用中若不注意路基模量的合理取值，将严重影响预估沉降的准确性。基于规范中使用的压缩试验成果和割线模量法，结合路基多维沉降性状，提出相应的非线性弹性模型。将该模型应用于Biot固结理论，建立了考虑模量随埋深和固结过程变化的Biot固结控制方程，并推导了FEM方程，设计了具有快速收敛性的余量迭代算法。算例分析结果表明，不考虑模量变化的几种常用方法存在较大偏差。本文方法有助于提高预估路基沉降的精度。

英文摘要：

Although the coupling mechanism of seepage and deformation in Biot＇s consolidation theory （BCT） is strict, the simulation results using BCT are usually influenced severely, if not taking into account of roadbed＇s modulus with an appropriate value. On the basis of the results of both the compression test adopted by the norm and the method of secant modulus of compression, a new nonlinear elastic model concerning multi-dimensional performance of roadbed is presented and applied to BCT in this paper. The governing differential equations and the corresponding FEM equations considering the variation of modulus with both depth and consolidation process are formulated. Moreover, a new residual iteration algorithm with rapid convergence is proposed. Through the analysis of a case study, the results show that the conventional method estimates roadbed settlement with a considerable deviation from the proper value. The presented FEM can be valuable to improve the prediction precision of settlement for more practical roadbed projects.