Evaluation of two-dimensional equivalent method for finite element analysis of consolidation by vertical drains

The two-dimensional equivalent method is one of the main approaches for the finite element analysis of consolidation by vertical drains. Summaries and comments about the equivalent methods are firstly carried out based on the existing researches. Then, six equivalent methods, which are widely applied in present, are examined through two numerical examples. The first one is the layered soft soil foundation and the other is the partially penetrated vertical drained foundation. The estimated results show that the parameter values for the layered soil example have significant impact on the reliability of the equivalent methods, while the length of the drain has no significant effect. For the parameter values applied in the examples, errors for the degree of consolidation for different methods vary considerably. The biggest errors reach 35% for different methods. Relatively, the calculated results of Chai's (2001) method and Tran's (2008) method are reliable and the largest errors of the two methods are within 10%. Besides, Chai's equivalent method is worth promoting since the operation of the method is rigorous and has high computational efficient.