Extending the strain path method analogy for modelling penetrometer installation

The Strain Path Method (SPM) is an approximate framework for simulating the disturbance caused by piles or penetrometers in soil. The key conceptual a ssumption of the SPM is that the deformation and strain fields caused durin g these penetration processes are strongly kinematically constrained (espec ially during undrained penetration of clays) and can be estimated independe ntly from the actual constitutive properties of the surrounding soil. Previ ous applications of SPM have estimated strain fields for a variety of penet rometer geometries using velocity fields of ideal inviscid fluids. This pap er refines the strain field for penetrometers with 60 degrees conical tips using numerically computed velocity fields in viscous fluids with a variety of boundary conditions imposed on the penetrometer shaft. Following a para metric study, a set of flow conditions is selected which provides a best fi t between computed soil deformations and physical displacement measurements made in three separate experiments. The approach is simple and rapid and, while highlighting some of the inaccuracies associated with the existing SP M solution, may also be used for comparative purposes to assist the develop ment of other approaches to the deep penetration problem. Copyright (C) 200 0 John Wiley & Sons, Ltd.