Effect of Temperature on Measured Strength Parameters from Variations in Both Storage and Testing Temperatures

Abstract

The effect of temperature on laboratory tested mechanical properties of clay has been debated for many years. The fact that soil parameters are affected by variations in temperature is generally agreed upon, resulting in recommendations regarding storage of sampled test specimens. Decrease of testing temperature has been shown to have a significant effect, with increases in preconsolidation pressure (p'c) and (su) of around 10% per 10°C. As of yet, there are no standardized corrections or recommendations made towards testing temperatures used.

In this work tests have been performed on cohesive clay samples from the Lilleby site in Trondheim, Norway. Selected index tests, CRSC oedometer tests and CAUC triaxial shear tests have been run in parallel, for two different storage periods, storage temperatures, and test temperatures. By examining trends across these permutations of the test environment, the goal has been to provide additional data on clay used in a typical construction projects.

The results of this work show clearly that the testing temperature has an effect on measured mechanical properties, on the order of 9% for p'c and 6% for su. The effects of storage temperature are less pronounced, and the same is the case for the storage duration. Findings are discussed in the context of previous literature, and some recommendations for further work are made.