If Coupled Eulerian-Lagrangian method can chase materials accurately ?

         What puzzled me at the moment is if this CEL method can chase materials during the simulation. More exactly, for NC clay (clay with linearly increasing strength),it is easy to assign shear strength to NC clay. I deem the shear strength is fixed in node in the eulerian mesh, when the clay flows to that point it will be assigned the pre-defined shear strength value, which means  the eulerian mesh can’t reflect the true situation(parts of clay around spudcan flow down passively may be assigned different shear strength from the true value due to the property of eulerian mesh).  Can anyone tell me the trick and give me some advice on how to settle this problem ?  

Looking forward to discuss with you. Your help is greatly appreciated!  My email: panhu@civil.uwa.edu.au 

Thanks ! Pan