A study on subsurface drainage of mountain roads in Bhutan
Sustainable Civil Engineering Practices
School of Engineering
© Springer Nature Singapore Pte Ltd 2020. There are many problems associated with hill roads in Bhutan. Since most roads are constructed through steep terrains, there are significant problems related to the slope stability and drainage system. The slope stability problem is massively localized and may not be easily avoided. On the other hand, the drainage problem which affects the larger portion of road stretches than any other factor might be reduced through proper construction of drainage systems itself. In the light of these facts, an attempt is made in this paper to recognize the sources of drainage problems and proposes a design of an economically viable subsurface drain for hill roads in Bhutan. It also presents the discharge calculation of a watershed for the design of roadside drainage system and discusses about determination of the rainfall intensity in Bhutan in order to understand the influence of rainfall on the stability of roads located on mountain hills, and mitigations measures methods are adopted to prevent amount of rainfall run-off reaching towards the roads.