The Askot–Lipulekh road section in Uttarakhand required a specialised engineering solution to support road widening works along steep valley-side terrain under highly complex geotechnical conditions. The existing carriageway, varying between 4 and 7 metres in width, was proposed to be widened up to 12 metres across slopes comprising loose soil intermixed with boulders and weathered rock. The presence of a high-velocity river flowing close to the toe of the valley slope, coupled with significant variations in geological formations and topography, necessitated a robust and reliable valley-side retention system to ensure long-term stability and safe connectivity along this critical Himalayan route.

Following a detailed technical assessment, a shored reinforced soil wall system was designed and implemented to provide stable valley-side retention. The solution comprised a flexible gabion-faced reinforced soil structure using Terramesh® units, in combination with high-strength monoaxial geogrids Paragrid HF and ParaLink®, enabling the construction of reinforced soil walls with heights ranging from 8.8 m to 26.4 m. Due to limited right of way, Self-Drilling Anchors (SDAs) in combination with ParaLink® geogrids were incorporated to achieve structural stability despite restricted reinforcement lengths, highly variable subsoil conditions, and the proximity of a fast-flowing river. This hybrid system facilitated efficient load transfer and uniform pressure distribution at the foundation level while accommodating the challenging ground conditions.

To complement the structural measures, roadside drains and subsurface drainage provisions were incorporated to manage surface runoff and subsurface water flow. Drainpipes wrapped with non-woven geotextiles were introduced to reduce pore water pressure within the slope and improve long-term performance. Collectively, these engineered interventions enabled safe road widening, ensured reliable valley-side retention, and delivered a durable reinforced soil wall solution well-suited to the demanding conditions of the Himalayan terrain.
Read more about our retaining wall and soil reinforcement solutions: https://www.maccaferri.com/in/applications/retaining-walls-soil-reinforcement/