Interpretation of the Consolidation Test

To create significant pore water pressure in a tiny test specimen of clay, it must be loaded with large increments. This causes the specimen to compress at rates to several million times the rate for an equivalent element of soil in the field. A laboratory investigation of compression rates, under incremental and continuous loading, showed that the compressibility of an undisturbed sensitive clay was greatly influenced by the rate of compression. These rapid tests gave pressure-compression curves similar to those for identical specimens, and demonstrated that the relative contributions of primary and secondary consolidation is a function of test procedure. When compared with long duration incremental loading tests, however, they revealed a much higher preconsolidation pressure and less compressibility. It was therefore concluded that the influence of compression rate may be important in the interpretation of consolidation tests and warrants more attention and research.