Study on slope stability analysis by using Slope/W software and manual calculations

Abstract

Slope stability analysis is widely used in determining the proposed slope meet the minimum safety requirements during design consideration. Inadequate design can lead to the slope failure and bring to the loss in life and property. Thus, this research is carried out to analyze the stability of slope along Ipoh-Lumut highway based on limit equilibrium method (Ordinary, Bishop and Morgenstern-Price) by using SLOPE/W software and manual calculations. The research started with the obtaining of site investigation report from Ikram Utara. Slope profile is drawn based on borelog and the parameters (unit weight, cohesion and friction angle) are labeled for each soil layers. The result from SLOPE/W software and manual calculations shows Ordinary methodhas the lowest factor of safety followed by Bishop methodand Morgenstern-Price method. The factor of safety in manual calculation is slightly higherthan in SLOPE/W software.For Ordinary method, the difference of FOS for both software and manual calculations is 0.133 (7.47%). while the FOS value for Bishop method varies for 0.073 (3.66%). Meanwhile, by comparing software and manual calculations, the FOS for Morgenstern-Price is differ by 0.07 (3.51%) and 0.045 (2.25%) for both force equilibrium and moment equilibrium respectively. Application of software provides greater advantages over manual calculations in terms of shorter time taken, able to solve complex problem and has higher result accuracy. Three methods stated are easily performed by SLOPE/W software while Ordinary method and Bishop method are preferred in manual calculations. Morgenstern-Price method and Bishop method are more suitable in real life application than Ordinary method. Future work is recommended with the application of other slope stability soft