Geological and geotechnical investigations for the Salang highway, Afghanistan

Abstract

The present road over the Hindu Kush Mountain Range via the Salang Pass (termed the Salang Corridor) links the south of Afghanistan, including the capital Kabul, with northern Afghanistan and Central Asia. It is the only route that allows year-round north–south passage of goods and people across the mountain range. However, the present road has suffered years of neglect and is now in a state of serious disrepair. In 2012, the United States Agency for International Development completed a study examining potential alternative routes. Three routes were selected for in-depth study and detailed engineering design. In mid-2017 SMEC International Pty Ltd were appointed to carry out a feasibility study to recommend the most suitable of the three routes and to then carry out a detailed design of the chosen route. This paper outlines the geological and geotechnical studies carried out during the project with a focus on investigations for the detailed design phase, and presents the geotechnical design recommendations arising from those investigations. This paper also explains the difficulties involved in carrying out the investigations including security issues, harsh weather conditions, and maintaining effective communication between the project team both in Afghanistan and around the globe during the COVID-19 pandemic.