Experimental study on soft sedimentary rock under plane-strain compression and creep tests

Experimental researches on soft sedimentary rocks can be found in many literatures, most of which were conducted in conventional triaxial tests due to the difficulties of plane-strain or true triaxial tests with soft rock samples. It is known, however, that the mechanical behavior of soft sedimentary rock is largely dependent on stress condition. In the paper, the plane-strain test apparatus and the experiment method used in the tests are introduced at first. Some special treatments aimed to acquire good test results have been proposed. Secondly, test results, including stress-strain relations and stress-dilatancy relations under conventional compression and plane-strain loading condition, are discussed in detail. Finally, results of drained creep tests under plane-strain loading condition are introduced.