Calibration Chamber Size Effects on Penetration Resistance in Sand

Calibration chamber tests provide an effective way to study cone penetration resistance in sands under controlled conditions. Calibration chamber tests are performed in large soil samples with known densities, consolidated to desired stresses, and subjected to known boundary conditions. Results from calibration chamber tests can be used to establish the relationship between cone resistance, soil density, and stress state. However, the penetration resistance measured in a calibration chamber differs from that measured in the free field because of chamber size and boundary condition effects. There has been considerable uncertainty about these effects, precluding use of the results of calibration chamber research with greater confidence. In this paper, a penetration resistance theory recently developed is used to quantify chamber size effect, to investigate the factors it depends on, and to show how to correct calibration chamber test penetration resistance values to free-field conditions. The theoretical results are compared with available experimental results.