Background
The Andean railways in Peru are vital for transporting minerals and agricultural products. Many sections run through mountainous terrain where culverts discharge stormwater and seasonal floods. Over time, culverts suffered from leakage, cracking, and reinforcement corrosion due to heavy rainfall, freeze-thaw cycles, and high-altitude conditions, posing risks to railway safety.
Challenges
-
High altitude (3,000–4,000 m): Large daily temperature swings and freeze-thaw cycles accelerate deterioration.
-
Intense rainfall and floods during the wet season.
-
Limited construction window, as works must be done under rail traffic closures.
-
Transport restrictions for materials and machinery on narrow mountain roads.
Technical Approach
A combined method of surface waterproofing, crack injection, and structural lining reinforcement was applied:
-
Surface preparation: High-pressure water cleaning; corroded reinforcement cleaned and coated.
-
Crack repair: Epoxy or PU grouting injected into leaking cracks to stop seepage.
-
Waterproofing layer: Two-component polyurethane coating applied; self-adhesive polymer membrane (3 mm) added in high-flow zones.
-
Lining reinforcement: Steel fiber shotcrete, 5–8 cm thick, applied in severely damaged areas.
Results
-
Length rehabilitated: ~180 m culvert
-
Duration: 60 days, executed in 4 rail closure intervals.
-
Outcome: All leakage sealed, durable waterproof lining achieved; culvert remained dry during rainy season.
-
Benefits: Service life extended by 20+ years, reduced maintenance costs, improved railway operational safety.