Developing guidelines for the protection of cut slope and embankment for roads in Rwanda

Abstract

Embankment and slope failure occur continuously throughout Rwanda. The cost of ramifications of these problems is high from an economic perceptive, the budget of the Rwanda government for this kind works is not enough, which limits inflexible constructions(structures). Protection measures for most sections of the cut slope and Embankment, never to the full length. These are costly and sometimes not efficient because of the designed fault and inappropriate construction for the designed life. Alternatively, protection of cut slopes, embankment slopes using plants are being used in several countries successfully. The main objective of this research will be to study and analyses the current practices and their application and the best international practices for slope protection. The analysis of the gaps existing between the commonly used practices in Rwanda and International Best Management Practices for the construction and maintenance of slope and propose guidelines, recommendations, and alternatives solutions like Bio-engineering which is the most suitable vegetation for slope protection. Use of vetiver plant in stabilizing road embankment and cut slope against rain and erosion can be efficient. Vetiver grass can grow in sandy silt. It has a high tolerance to weather variation. Moreover, it is not grazing-type grass. So, it is sustainable vegetation. Its root has a high tensile strength which grabs the soil firmly. The vetiver system is cheaper and more environmental friendly than other methods. No special equipment or skilled labor is required for implementing this method. However, periodic maintenance is required for this system. The price to protect the slope using vetiver plants is normally lower than the cost of other available slope protection measures. Vetiver planting has been found to improve slope stability by 50 percent. Therefore, it can be said that the vetiver grass plant can be used in Rwanda as a cost-effective and sustainable green solution for slope safety and Embankment against rain and erosion in Rwanda a cost-effective and sustainable green solution for slope safety and anti-rain and anti-erosion shipping.