The RKF-23 time integration scheme was programmed and kindly provided by Prof. C. Tamagnini and E. Sellari. The original umat - PLAXIS interface, which served as a basis for the present developments, was programmed and kindly provided by Dr. P.-A. von Wolffersdorff. The implementation was optimised during the stay of the author at Plaxis bv in March 2010. Plaxis support is greatly appreciated. Development of constitutive models was supported by the research grant GACR 205/08/0732.
Software was developed under support of grant TACR TA01031840.
