The use of a specially designed hollow cylinder cell in the measurement, under laboratory controlled conditions, of the lateral stress and the excess pore water pressure induced by a cavity expansion in both clayey and granular soils is discussed. The hollow cylinder cell permits the performance of a cavity expansion test in an annular soil specimen under three independent stresses (i.E., Axial stress, radial cavity pressure, and lateral confining stress) with measurement of cavity volume change and excess pore water pressures at several locations in the soil specimen. Effective stress analysis of thesoil response to the cavity expansion illustrates that the effective lateral stress is independent of the specimen geometry, and intrinsic effective stress-strain relationships can be derived from the experimental expansion curve. However, the specimen geometry does affect the excess pore water pressure generated under undrained conditions, and, therefore, the total stress analysis conventionally used for interpretation of pressuremeter test results is not appropriate for analysis of hollow cylinder cavity expansion test. This paper appears in transportation research record no. 1278, Dynamic testing of aggregates and soils and lateral stress measurements 1990.
Samenvatting