Observations of the Landslide Mitigation of Rock Slopes on the Pilgrimage Route Between Makkah and Mena in Saudi Arabia

The pilgrimage route between Makkah and Mena in Saudi Arabia is heavily used during the pilgrimage season. Just within three days, millions of pilgrims take this route. The route lies in high rock and steep mountains with moderate to high landslide risk. The rock slopes were cut to enable road construction, increasing the risk of landslides. Therefore, a wide range of slope stability measures were applied to ensure the safety of people using the route and to reduce landslide risks. Barriers such as gabions and concrete beams were constructed on the slope surfaces. Rock netting, nailing, and shotcrete were also applied to protect the rock slopes. However, the slope stability measures are insufficient in several locations to minimize the risk. Therefore, a risk remains, which has to be considered further. This paper presents observations on the implemented slope stability measures and discusses their shortcoming. In addition, a qualitative hazard assessment was also conducted, and recommendations for further remediation were suggested.