Evaluation Of Embankment Stability For New Diversion Channel Under Various Loading Conditions

This study investigates the stability of the channel embankment associated with a flood mitigation project known as Sungai Baru Diversion channel located in Kedah, Malaysia. The stability of the channel embankment were investigated for different type of soil such as clay, silty clay, silty clay loam and loam; and different loading conditions namely at the end of construction, during steady state, during flooding, and after rapid drawdown. A site investigation was carried out at the site and the data gathered were utilized to model and analyze the embankment stability at various loading conditions using softwares namely SEEP/W, SIGMA/W and SLOPE/W. Embankment constructed with clay produced the lowest factor of safety when compared to embankment made of other soils. For clay embankment, the factor of safeties obtained were 1.39 at the end of construction, 3.75 during steady state, 3.7 during flooding, and 1.33 during rapid drawdown. At the end of construction, clay embankment also possessed the highest deformation for the surface of the foundation as compared to embankment constructed with other soils. Based on the analysis, a settlement of 164 mm and heave of 72 mm were anticipated at the central position and near the toe area of the embankment respectively. 9 reinforcement methods using non woven geotextile have been proposed and analyzed. It was found that the reinforcement method of conventional configuration using 3 m length of non woven geotextile gives the best result in terms of stability and deformation. In conclusion, this study proved that a realistic and comprehensive modeling for a channel embankment could be carried out in order to assess stability under various loading conditions for selecting the most appropriate stability enhancement method