*Rossella Luchi¹、S. Balachandar²、Giovanni Seminara³、Gary Parker^1,4 (1.Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA. 、2.Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, Florida, USA. 、3.Department of Civil, Environmental and Architectural Engineering, University of Genova, Genova, Italy.、4.Department of Geology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA.)