General axisymmetric active earth pressure by method of characteristics - Theory and numerical formulation

Active pressure for axisymmetric problem under general conditions is formulated and solved by an iterative finite difference solution of the characteristic equations in the present paper. A general lateral stress coefficient is used instead of the Haar-von Karman hypothesis and numerical modeling has also confirmed that Harr-von Karman hypothesis is a reasonable assumption for the present problem if sufficient wall movement is allowed. The shape of the failure zone and variation of active pressure with depth and wall friction are investigated. Some interesting results on the active pressures arising from the arch action are found. Principle of superposition of the effect of soil weight, surcharge, and cohesive strength is discussed. Finally, the results in the present study are applied to bore pile construction and it is demonstrated that no casing for construction is required under some conditions.