Weathering as rock degradation under the direct influence of environmental conditions and human activity in the engineering period of time, is a key process that affects geomorphologic, ecologic and societal processes and events. Soft rocks, such as marl, are very common in the Mediterranean and particularly susceptible to weathering. This is manifested through the decomposition of the binder from clayey rock structure and breaking of the rock structure due to physical and chemical processes. Under such influence, weathering degrades soft rocks to fine-grained material, which is related to environmental sustainability (erosion, climate change issues, slopes, rock falls and other geohazards), stability, bearing capacity and durability issues (temporal change of strength and deformability).
According to recent scientific findings, a significant contributor to the development of weathering is the process of differential suction and induced differential swelling, which occurs in unsaturated conditions. Differential suction comes as a result of capillary effects in voids of the material and it is closely related to slaking of the material. The consequences of differential swelling are development of tensile and shear stresses that cause weathering. Therefore, the aim of this project is to investigate and simulate the mechanisms of weathering from the aspect of suction, and to link the acquired new findings with the significant previous research carried out at the Faculty.
The shear strength and deformability in unsaturated conditions for the given degree of suction, and the characteristic SDSWCC curves (Stress Dependent Soil Water Characteristic Curve) will be determined by sophisticated testing equipment on still unexamined soft rock material from the Croatian coastal area. At the same time all “accompanying” tests, including physical, mechanical, mineralogical and petrological, will be carried out and new and existing databases will be linked. Full experimental programme will be carried out on approximately 30 specimens.
The obtained results will be incorporated into the existing numerical model (Plaxis) and into additionally developed new numerical model based on a discrete approach, which will include the fracture mechanism in geomaterials in unsaturated flow conditions. This will significantly improve the knowledge of weathering mechanisms in geomaterials and enable sustainable project solutions.
A newly formed research group with the necessary resources provides additional value of the project.