In general the problems of soil mechanics often divided into two distinct groups-the stability problems and the elasticity problems. The stability problems deal with ultimate failure. With direct shear box apparatus a study on the frictional behavior between Han River sand and some construction materials was made and the results were expressed by Mohr-Coulomb failure criterion. It was found that the internal friction angle of Han River sand at ultimate state is 36.5° and the surface friction angle between Han River sand and rusted steel is 34.5°.
