抄録
A theoretical formulation for the incorporation of constraint conditions imposed upon the displacement/velocity field of the soil-water coupled system is presented along the finite element discretization scheme. The"no-length change", "no-angle change"and"no-direction change"conditions are introduced as internal constraints to the displacement/velocity field through the Lagrange multiplier method. These multipliers are then interpreted as the internal constraining forces acting between the soil and the"constraint mechanism"system. The mathematical background of the method is first outlined in the INTROKUCTION to give a clear perspective using introductory finite element formulation. The method of analysis is illustrated through several examples of the simulation of load controlled undrained triaxial tests and displacement controlled plane strain undrained compression tests of the normally consolidated original Cam clay. In these tests the load application is made through a rigid pedestal which provides a"mechanism"for applying constraint conditions to the displacement/velocity field at the top of soil samples. The interaction between soil and pedestal is solved automatically and the reaction force from the pedestal to the soil and its distribution along the pedestal are obtained simply by computing the vector of the Lagrange multipliers. Thus it is found that broad applicability to the geotechnical engineering problems emerges from the present formulation.
