Slurry composition effects on soil-cement mixtures

Soil-cement mixtures were prepared using three types of materials sandy soil excavated from a shield tunnelling construction site in Tokyo, clay slurry used for stabilizing the shield tunnel cutting face, and cement. These soil-cement mixtures were planned to be used for the filling of the lower part (invert section) of the circular shield tunnel cross-section in place of cement mortar. A number of unconfined compression tests were carried out to investigate the time-dependent variation of compressive strength of soil-cement mixtures. The strength of soil-cement mixture was found to be satisfactory as the new invert material and to be influenced by the contents of the clay slurry. It could be seen that the density of soil-cement mixtures measured immediately after mixing and compaction was directly related to the compressive strength.