Investigation of soil reinforcement according to the root cohesion changes in hornbeam (Carpinus betulus L.)

The degree of soil cohesion investigation through the presence of roots is one of the important criteria in soil reinforcement studies. In this study, the investigation and comparison of the degree of soil cohesion have been carried out using two models of WWM and FBM. For this purpose, seven hornbeam (Carpinus betulus L.) trees were selected in each three sites of chalos sarcheshme forest, series one. Then profile trenching method was used to analyze and compare root distribution and standard instron device have been measured tensile strength, respectively. The root area ratio (RAR) has decreased with increasing depth, and the maximum value of RAR in the three sites is seen at about 40 cm from the beginning, and the maximum depth of rooting is 60 cm. The results confirmed that there was a power law relationship between root diameter and tensile strength. The minimum and maximum tensile strength was estimated at 11.52-323.42, 6.89-318.79 and 6.91-312.66 MPa, in diameter range of 0.5-9.45,0.56-9.21,0.45-9.32 in the first, second and third site, respectively. In all three sites, the amount of soil cohesion through the presence of roots using the WWM model was 4.04-61.37,5.7-53.18,4.6-46.66 kpa and in FBM model the root cohesion in all depth was 1.22-27.48,1.87-24.22,1.85-19.04 kpa in the first, second and third site, respectively. Comparison of these two models increases our knowledge of the biomechanical features of the hornbeam species and more accurately determines the amount of soil reinforcement to be used in the future in the management of natural phenomena such as landslides.