Highway Construction Project, Highway No. 1322 (Mae Ja - Rin Luang) KM.95+323
Location
Chiang Mai, Thailand
Client
Dept. of Rural Roads
project type
Infrastructure
CHALLENGES & INNOVATIVE SOLUTIONS
CHALLENGE
Landslide Rehabilitation in Active Hydrological Environments
Repairing a severe landslide along Highway No. 1322 in Chiang Mai presented complex geotechnical and hydrological challenges. Executing earthworks on an already failed high slope directly adjacent to a natural waterway during the monsoon season critically amplified the risks of further collapse.
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Active Slope Instability: The high-angle slope had already experienced a landslide, leaving the remaining soil mass highly vulnerable during remedial earthworks.
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Active Toe Erosion: The excavation site was located directly on a riverbank, exposing the base of the slope to continuous hydrological scour and water currents.
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Monsoon Weather Constraints: Heavy, continuous rainfall during the wet season drastically reduced soil shear strength and severely complicated slope cutting operations.
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Surface Water Infiltration: Uncontrolled surface runoff from the highway above threatened to wash out the exposed, compromised slope face during construction.
SOLUTION
Phased Geotechnical Intervention and Active Water Management
To safely reconstruct the failed earth mass and establish a permanent riverbank defense, the engineering team executed a top-down structural stabilization strategy combined with rigorous water control protocols.
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Sequential Deep Stabilization: Applied benching and soil nailing techniques to safely secure the high slope in controlled stages during the cutting process.
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Hydrological Flow Control: Executed temporary river redirection to divert water currents away from the work zone, effectively eliminating toe erosion during base excavation.
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Surface Runoff Interception: Installed temporary curbs at the crest of the slope to aggressively manage and redirect heavy rainwater away from the vulnerable cut face.
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Robust Scour Protection: Constructed a massive gabion wall system at the embankment base to provide permanent retaining support and long-term defense against riverbank erosion.
THE OUTCOME
Rapid and Secure Landslide Remediation in Severe Weather
Despite the hazardous combination of an actively failed slope, continuous river erosion, and heavy monsoon rains, the engineering team executed the rehabilitation flawlessly. The strategic integration of water diversion, surface drainage, and top-down benching enabled the rapid and secure construction of the permanent gabion wall. Ultimately, the project was completed safely within a highly compressed timeframe, successfully restoring the structural integrity of the highway and permanently fortifying the adjacent waterway.
100%
HAZARD MITIGATED
ZERO
SAFETY INCIDENTS
6 m
soil nail depth
