Fully Coupled Numerical Methods and a Simple Method for Calculating Settlements of Foundations and Reclamations on Clayey Soils

Many foundations are supported by clayey soil ground. Marine reclamations are mostly constructed on seabed consisting of marine clayey soils or marine deposits. The settlement calculation of such foundations and reclamations is needed for their design and performance assessment. In this paper, the authors will firstly give a brief introduction to issues and mechanisms of large settlements of soft clayey soil grounds caused by creep of clayey soil skeleton. The authors will present both Hypothesis A and Hypothesis B methods for calculating consolidation settlements of clayey soils, and the history and equations of the two methods, explaining the inherent logical mistakes of Hypothesis A method. After this, the authors will briefly present fully coupled numerical methods using different Elastic Visco-Plastic (EVP) models for consolidation analysis of clayey soils. They will then introduce a simplified Hypothesis B method, namely simple method, for one-layer and multi-layers of clayey soils. Steps of how to derive this simple method are presented. Two examples of using this simple method by hand calculations or Excel calculations are explained. Verifications of the simple method by comparing with test data and fully coupled numerical methods are presented. Conclusions and remarks are presented at the end.