Influence of Hillside Gradient on Forest Road Cross Section Components in a Loamy Clay Soil

Abstract

Problem statement: In this study to evaluate the effects of hillside gradient on forest road cross section components in a loamy clay soil the amount of cut and fill slopes gradient and length, road bed and earthwork width were taken on tangent sections in a lat talar forest roads of Iran. Approach: The objective of this study were: (i) to evaluate the direct effects of hillside gradient on cross section components such as cut and fill slopes, road bed and earthwork width in a loamy clay soil, (ii) to use the model to predict the effect of hillside gradient on cross section components. Results: Results indicated that the regression analysis between hillside gradient and cut slope length had a significant linear relationship (p<0.0001), with equation of Y = 0.046+0.054 X (R² = 0.60). The equation for the calculation of earthwork width (Y) from hillside gradient was Y = 4.928+0.132 X (R² = 0.44). A significant linear relationship (p<0.0001), with equation of Y = 0.144×- 2.638 (R2 = 0.64) was found between hillside gradient and fill slope length values. Conclusion: Through analysis of variance it was also found that the hillside gradient had a significant influence (p<0.0001) on the cross section components.