Road Cut Slope Stability Analysis For Static & Pseudo-Static Conditions And Comparative Study Of Slope Profiles (Case Study: Ambo To Gedo Road Project, Guder).

Abstract

Slope Instability Has Been Identified As One Of The Most Natural And Man-Made Disasters That Can Lead To The Life Of Humans In Danger And Enormous Loss Of Capital. The Roads Which Pass On The Hilly And Mountainous Terrains Are Frequently Affected By Slope Failures Since Hilly And Mountainous Areas Are Characterized By Variable Topographical, Geological, Hydrological, And Land-Use Conditions. Slope Stability Analysis And Comparative Study Of Slope Profiles (Slope Modification Methods) Are Studied In This Research Work. The Stability Analysis Was Carried Out Using Fem (Plaxis 2d) And Lem (Slide Software). The Stability Analysis Covers Both Static And Dynamic (In Pseudo-Static Analysis) Loading Conditions On Selected Soil And Rock Critical Slope Sections. Two Soil Critical Slope Sections And Two Rock Critical Slope Sections Are Analyzed In This Study. The Strength Reduction Method And Method Of Slice With Mohr-Coulomb Model Were Used In Fem And Lem Respectively. The Slope Stability Analysis Was Carried Out For Both Dry And Wet States Of The Soil And Rock Critical Slope Sections (I.E. Static Dry, Dynamic Dry, Static Wet, And Dynamic Wet). The Analysis Result Shows Soil Critical Slope Sections One And Two Are Stable In Dry Conditions And Unstable In Wet Conditions. Rock Critical Slope Sections Are Stable During The Dry And Wet States Of The Slope. From The Comparative Study Of Slope Modification Methods Flattening The Slope ( From Real Site Condition I.E. 40???) To 35???, 30???, And 25??? Increases The Factor Of Safety Of The Slope By 9.89%, 18.87%, And 32.88% Respectively. The Use Of 2m,3m, 4m, And 5m Bench Width By Keeping The Slope Angle Constant And Slope Height Of 10m Increases The Factor Of Safety By 8.23%, 14.87%, 17.04%, And 27.54% Respectively When Two Numbers Of The Bench Are Used. Using Multi-Slope Profile By Keeping The Lower Stiff Material With A Constant Slope And Changing The Slope Of Upper Slope Material. The Use Of Upper Layer To Lower Layer Slope Angle Ratio Of 1.05, 1.13, 1.2, 1.4, 1.6 Increases The Factor Of Safety Of The Slope By 9.31%, 12.68%, 17.53%, 24.64%, And 41.63% Respectively. A Soil Nail With 15?? Inclination, 2m Nail Spacing, And An Increase Of Soil Nail Length Start From 0.7h Is Used In Soil Nailing Method. A Fs Of The Slope Increases With Increasing Of The Soil Nail Length Until The Effective Length Of The Soil Nail And Remains Constant When More Length Of The Nail Is Used. The Use Of A Combination Of Surface Drainage With Benching Is Recommended Which Means Lateral Drainage (Bench Drain) To Collect Rainwater From Each Bench Slope And Drain It Laterally To Spillways.