Abstract: This study aims to extend the scope of cutting plane algorithm for calculating the constitutive equations in the bounding surface model. Moreover, a new algorithm should inherit the simple and efficient framework in the classical elastoplasticity model. The maximum limit of incremental step was employed to propose a modified cutting plane method by using an adaptive sub-stepping algorithm. This method was also applied to an improved bounding surface model for structured clay. Experiments were conducted on Shanghai clay to validate the bounding surface model using the modified method. The validation of the modified method was proven through obtained results. According to parameters of Shanghai clay, numerical studies were also carried out to simulate undrained triaxial tests, undrained simple shear tests, undrained triaxial cyclic tests and oedometer test, respectively. The maximum limit of the incremental step was further determined. Finally, an undrained single shear test was simulated under the large strain step condition by using the modified method. As a result, the accuracy and stability of the modified cutting plane method were verified.

Key words: cutting plane algorithm, bounding surface model, elastoplasticity, maximum limit of incremental step, adaptive sub-stepping