LABORATORY INVESTIGATION OF EMBANKMENT SETTLEMENT CAUSED BYMARL GRAINS DETERIORATION

Sa？etak Embankments made of crushed soft rock grains can be susceptible to additional settlement caused by deterioration of the grains inside the embankment. This additional settlement is not caused by the change of the stress state inside embankment and cannot be predicted by standard calculating methods with the embankment modulus of deformability measured after compaction of the embankment. The deterioration of the grains is mainly caused by the weathering process which is, in soft rocks such as marl, mainly induced by the wetting and drying processes. If marl grains in an embankment are subjected to the wetting and drying process, the result is breakage of the grains, as well as decomposition into soil material. Disintegrated material then fills the macropores of the embankment grain structure and gradually causes additional settlement. The samples were made of crushed marl in laboratory conditions. A test was conducted with modified oedometer apparatus. Measured values can be used for estimating the additional settlement caused by the weathering