Theory of Deep Site Static Cone Penetration Resistance.

摘要

The static cone penetration test combines simplicity,consistency and reliability in determining in situ soil properties during deep site investigation. The available methods of interpreting test results are summarized and the need for a better understanding of the penetration mechanism is emphasized. A theory for sharp cone penetration in clays is presented. The theory is based on dividing the work done during penetration into two parts: (1) the shearing due to penetration by cutting without volume change,and (2) the development of a cylindrical cavity to account for the volume of the pushing rods behind the cone. The clay deformation due to blunt pile penetration is also predicted and compared with experimental results. Cone penetration in sands is difficult to formulate because of compressibility and curvature of the failure envelope of the soil. The pressure to expand spherical and cylindrical cavities are computed by the program EXPAND,which introduces both compressibility and envelope curvature in the analysis. The correlation between the expansion pressures and cone penetration resistance should be obtained from well controlled tests.