Rockfall Hazard and Risk Assessment along Aizawl-Durtlang Road Section, Mizoram, India

Rockfall Hazard and Risk Assessment along Aizawl-Durtlang Road Section, Mizoram, India

ABSTRACT

Aizawl is growing in an anticline where Middle Bhuban rocks are found be present along ridge which show high topographic slope on both sides of the axis. The elevation difference, high slope variability, variable rock strength and litho-association are important factors in the stability of the rock beds around the region. The area is susceptible to many landslides and some of them are also subjected to rockfall events. Most common rockfall event have been observed in Aizawl Durtlang road section. In this area vulnerability study has not been done to such an extent and therefore hazard assessment was required to understand the hazardous localities. The area is subjected to rockfall events rather than other sliding mechanisms occurred in other areas. The geologic map and profile along the road section indicate sandstone dominating arenaceous lithounits are present with interbedded shale and siltstone. The structural attributes and other thematic maps indicate that the most of the sections are favourable for rockfall events. The stereoplots for the joint surfaces also reveal that the area is also susceptible to wedge failure, that again lead to rockfall events. This study also reveals that activities like slope cutting or building construction without any adequate measures can lead to such a catastrophic event in the area.

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