Son La City Bypass, Son La Province, Vietnam

Along the Son La City Bypass alignment, several cut slopes showed signs of surface instability caused by weathering, variable rock mass conditions, and intense seasonal rainfall. The excavated slopes comprised heterogeneous and fractured materials with reduced inherent strength, making them vulnerable to shallow failures. During heavy rainfall events, surface erosion, loose rock raveling, and localized detachment of weathered material were observed, posing potential rockfall and debris risks to road users and threatening long-term slope performance.

To address these challenges and support safe, uninterrupted road operation amid growing traffic demand, Maccaferri MacMat® HS30 was selected as the primary surface-strengthening solution. The high-performance geomat combines a 3D polymer matrix with high-strength steel mesh to deliver effective erosion control and mechanical reinforcement. In areas of rocky strata, SteelGrid® HR30 was applied to enhance surface confinement and overall slope stability.

Anchored using soil nails or rock bolts according to site conditions, the system formed a continuous, flexible protective layer that adapted to the irregular slope geometry, mitigating erosion and reducing the risk of shallow failures.nectivity. The completed works reinforce the surrounding landscape, enhance road safety, and support reliable operation for decades ahead.