Further investigations, such as grain-size analysis and examination of two additional samples under the SEM to be compared to the sample from Section 186-1151-51R-1, will finally complete the data presented here. Results of the construction of the Mohr-Coulomb envelopes and the construction of a "hypothetical" envelope by using the dip angles of the produced failure planes, respectively, will complete the experiments and permit an interpretation of the shear parameters in terms of comparison of both sites.