Hydraulic piping—theoretical and experimental findings

The safety factor for piping by heave was conceived as a minimum criterion (probably in 1929 by Baumgart and Davidenkoff, certainly in 1943 by Terzaghi). The minimum condition of the criterion is frequently omitted. This paper gives the relation of the criterion to first principles and indicates solutions for the piece-wise homogeneous and linear inhomogeneous soil. Theoretical and experimental evidence shows that the omission of the minimum condition yields upper bound estimates for the safety factor and is equivalent to assuming homogeneity. It is concluded that in general the assumption of homogeneity is significantly on the unsafe side.