engleski

Weathering process in Eocene flysch in region of Split (Croatia)

The Eocene flysch in the region of Split (Dalmatia, Croatia) is characterized by the presence of layers with different characteristics. It mainly includes thin-layered marls, clayey marls, calcareous marls, clastic layered limestones, calcarenites and breccias. Those parts that can be described as the soft rocks or hard clays by the mechanical means, exposed to weathering reduce the durability within "an engineering time scale". The paper deals with the factors that influence the weathering process. The analyzed weathering is a combination of processes acting simultaneously. Most of these processes depend on the change of the water content, thus the weathering process mainly develops when a material is subjected to the wetting-drying process. On the base of these results form of degradation process is modeled. The weathering process can be mainly described as physical weathering combined with chemical weathering on the free surfaces and on the cracks walls. Erosion as a result of weathering, is the dominant geomorphic process on analyzed flysch terrain. According to the analysis, as the most appropriate due to the characteristics, the tests are chosen as index properties. Some of these tests are modified in order to adapt them to the determined characteristics of materials from flysch layers. The correlations between the measured values are used as the basis for the classification proposal of the analyzed material, according to its resistance to weathering processes. Roughly, three main groups of samples are recognizable: the first one with carbonate content more then 90% is not weathered at the engineers time scale ; the second group with carbonate content from 75% to 90% include samples susceptible to weathering in engineers time scale ; the third group with carbonate content less then 75% include samples in which the weathering occurs immediately after the exposition to the weathering factors.

Weathering; Flysch; Classification

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