ESTIMATING MODULI AND FRICTION ANGLE FROM SELF-BORING PRESSUREMETER TESTS IN SAND

Abstract

Self-boring pressuremeter test (SBPMT) data has been analyzed based on cylindrical cavity expansion method and dimensionless cylindrical cavity expansion factors (F"_q) to determine angle of friction, rigidity index (I_r) and modulus of elasticity (E). Then, based on a hyperbolic model, secant modulus (E_sf), secant modulus at 50 percent failure stresses (E₅₀), and initial modulus (E_i) have been determined. Reasonable values of angle of friction, initial modulus (E_i), and secant modulus of deformation at failure (E_sf) have been determined for sand deposits located in different geographical regions. The secant modulus (E₅₀) determined by this method compares well with unload-reload modulus, E_r, determined from unload-reload cycle of the SBPM tests.