Highway tunnels shorten routes, improve gradient and curve geometry, and remove winter road closures. Deha Altyapı carries out every item of tunnel construction — from the geological investigation stage to the final lining concrete — with its own technical team and equipment.
Work begins with the excavation method chosen for the ground class. Controlled blasting is used in competent rock, mechanical excavation in weathered and weak ground. After each advance the face stability is assessed and the support class applied accordingly.
Support and lining
Primary support combines shotcrete with steel mesh, rock bolts and steel sets. Ground behaviour is monitored continuously through convergence measurements and instrumentation. At the final stage a waterproofing membrane is laid and the lining concrete is cast using a formwork carriage.
Tunnel drainage, ventilation, lighting and fire safety systems are designed and built into the works in line with the relevant authority specifications.
