Development of a seismic self-boring pressuremeter

Development of a new self-boring pressuremeter has been the opportunity to insert geophone in the body of the probe. Placed in the shoe and the head of the probe, the geophones allow the determination of compression (P) and shear (S) wave velocities close to the cavity subjected to the expansion. To simplify the data acquisition, all hardware and software components are designed to run with a notebook computer connected to a signal conditioning system. The determination of P-wave and S-wave arrival times from the recorded time series permits the derivation of soil elastic constants of Poisson's ratio, shear modulus, bulk modulus and Young's modulus. This probe has been tested on an experimental site of the French National Public Works Network where well-documented trial embankments have been followed during 30 years. This site is set on a thick layer of organic normally consolidated clay. A detailed analysis of the results of these techniques is presented.