engleski

Time-dependent behaviour of reinforced cuts in weathered flysch rock masses

Knowledge of stress-strain rock mass behaviour is crucial for many engineering purposes. Rock mass deformations and their influences on construction are observed during construction and even during exploitation phases. These deformations in the exploitation phase are caused by the time-dependent behaviour of the rock mass. A flysch rock mass is categorised as a heterogenic weak rock that has been intensely subjected to weathering processes. Due to weathering processes, the flysch rock mass degrades from fresh rock to residual soil within only a few meters of the geological profile below the surface. Observations of reinforced cuts along the Adriatic motorway near the City of Rijeka, Croatia, were conducted over a time period of seven years of spanning construction and exploitation. Measured displacements reached significant magnitudes during the exploitation period as a consequence of the time-dependent behaviour of the rock mass. The paper presents findings related to flysch rock mass weathering profile and its characteristics based on detailed geotechnical investigations and monitoring results coupled with back analyses. It was found possible to detect the thickness of the flysch rock mass weathering profile by performing detailed geotechnical investigations. Recommendations for the strength, deformation, and creep properties of the weathering profile of a flysch rock mass are given.

time-dependent behaviour; weathering; weak rock mass; Burger model; back analyses

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