The three·dimensional effects on the stability of vertical cuts in cohesive slopes whose undrained strength varies linearly with depth is examined. The failure surface is assumed to be cylindrical with cortical end caps, having its axis of rotation on the crest of the slope. The soil, which corresponds to normally consolidated clay may or may not have a finite strength value on the ground surface. Constant strength with depth is examined as a particular ease. The problem was solved analytically resulting in a closed form equation for the three-dimensional factor of safety. The variation of the ratio of the three-dimensional to the two-dimensional factor of safety is studied for different linear strength variation configurations and for a variety of failure lengths of both the cylindrical and the conical parts. It is shown that the factor of safety in three-dimensions is dependent upon the height of the slope. For the specific length of the cylindrical part there exists a critical length of the conical ends. This critical length increases for increasing strength variation slope and it practically disappears in the ease of zero strength on the ground. In the case of zero strength on the ground, end effects can be ignored for a length of caeh conical part greatcr than three times the height of the slope.
The three …
AUTORI: Cavounidis S., Kalogeropoulos RIG ANNO: 1991 NUMERO: 2 Numero di pagina: 85