Results of mechanical parameters of hornbeam (Carpinus betulus L.) originated from slope near Ciężkowice (Pogórze Ciężkowickie Mts.) are presented in the paper. In the frame of research were performed tensile force tests, were determined root area ratio within soil profile and shear strength tests of soil and reinforced soil were done. Tensile strength tests were carried out in the tensile testing machine manufactured by Hounsfield H50KS on samples with a length of 0.1 m using a strain speed of 10 mm per minute. Shear strength tests were performed in a direct shear box with measurements 120 x 120 mm for soil samples and soil reinforced by 6 and 10 roots of hornbeam. Results of tensile tests and their analysis revealed that hornbeam roots are very strong in comparison to some species of plants. Root area ration measurements show that the highest density of roots was observed in the upper superficial layer of soil profile (at the depth of 0,3 m below terrain level) and at the depth 1,0 m below terrain level were observed individual roots. Maximum value of root area ratio was equal to 0,6% and it was smaller in comparison to tests results obtained for this species cited ...
The paper presents results of shallow landslides research located in Siary near Gorlice in June of 2010. In the frame of investigations were done in-situ tests including evaluation of geologic- engineering condition near the landslides and laboratory tests including determination of geotechnical properties of soils (grain-size distribution, Atterbergs' limits, shear strength parameters). The main part of paper included analysis of infiltration process and its influence on stability of slope. There were used two methods describing water flow through unsaturated soil: piston model of Lumb and Montrasio-Valentino model. Tests and slope stability analysis results proved that main factor controlling failure of analyzed parts of slope were very intense rainfall, which caused saturation of superficial slope layer built of gravelly silt. The another factor which contributed to saturation were impermeable soil layer of cohesive soil. Integrated infiltration and slope stability calculation results using Montrasio-Valentino model revealed its sensitivity on K parameter, which describes drainage capability of soil. It was indicated that K parameter can be interpreted as function of coefficient of permeability. Slope stability calculations made using Montrasio-Valentino model in analyzed case gave less values of stability factors than the ones based of infiltration calculations using piston flow model.
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