Geotechnical Properties of Lacustrine Carbonate Sediment

Results of laboratory tests on specimens produced from subsoil studies were evaluated tocharacterize geotechnical properties of Tabriz Marl. It was concluded that, Tabriz Marl may be considered as a high liquid limit silt or clay (MH & CH). Range of changes of index, physical and mechanical properties of the Tabriz Marl are comparatively vast. Correlation between these properties has been introduced in this paper. A representative specimen was tested for swell potential after compaction and also for thermal and lime treatment effects. Swell percent and pressure as high as 13.6 % and 1020 kPa were measured and need for treatment was proved. It was shown that with thermal treatment substantial modification only starts as the temperature rises beyond 300° C. At 500°C the plasticity index and also the swell percent decrease to less than 5.0 % and 1.0 %, respectively. With lime treatment, plasticity index decreases as the lime content is increased until the lime fixation point is achieved at about 3 % lime content, beyond which, modification effects are not considerable.Addition of just 1.0 % lime to the soil decreased the swell potential to 5.0 %. Further results, merits and shortcomings of both treatment methods are introduced during the text.