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Erosion of alluvial soils along the Ohio River is a matter of increasing concern to riparian landowners and commercial interests. One mechanism by which erosion of alluvial streambanks takes place is by sliding wedge failures of upper bank layers. Results of a study are presented in which the sliding wedge mechanism was investigated for Ohio River banks. Streambanks were assumed to fail by sliding along sand partings underlying cohesive upper layers. Results of computer wedge stability analyses indicated that bank stability is most sensitive to the depth of water present in tension cracks behind the face of the bank. Other factors found to be important to wedge stability are the effective angle of internal friction of the sand seam underlying the cohesive sliding wedge and the unit weight of the cohesive wedge. The importance of tension crack formation on wedge stability of multilayered river banks was also evaluated.

A series of onedimensional compression tests was performed at vertical pressures as high as 689 MPa (100,000 psi). Three materials were tested: Ottawa sand, a granulated slag called Black Beauty, and soda lime glass. Glass specimens included three grades of spherical particles and one grade of angular particles. Test results showed how particle crushing is influenced by initial void ratio, particle size, particle angularity, and particle material composition. Three phases of compression behavior were identified: Volume decrease as a result of particle rearrangement at low stresses, characterized by a low “initial” constrained modulus; more intense compression as particles crush and are rearranged extensively under higher stresses; and, as the number of contacts between fractured particles increases greatly at very high stresses, an approach to pseudoelastic behavior characterized by very high values of constrained modulus typical of natural sandstones. Even though the tested specimens varied in mineralogy, initial void ratio, median grain size, particle shape and initial moduli, they showed little variation in final constrained modulus.