Lattice Girders

Applying Lattice Girders as a profile arch in tunneling improves the defects of H beam profiles though it has higher stiffness performance. The improvement includes integrating the shotcrete with steel profile into a uniform RC structure and gaining earlier bearing capacity to support the tunneling excavation. It also improves the water-tightness of the outer lining.

The Lattice Girder is composed of high strength deformed bars or round bars and designed with same section modulus as the corresponding H beam Profile. To ensure the quality of lattice girder, various loading tests of all steel elements and parts are carried out. The welding job is checked through a destruction test after every 5000m production for each individual welder.
Specification
Three bars - 50/25/20 ~ 130/34/25
Four bars - 100-18-4B ~ 190/34/4B
Safety/Quality Approval
Main bars - ASTM A615 Gr.75 or BS B4449 B500B
Connection bar - ASTM A615 Gr.60