Lattice Girders 3 Bar / 4 Bar
Advantages
Advantages with the use of Lattice Girders
Lattice girders provide the following advantages:- Immediate roof support over the excavated section.
- Act as a template assuring a minimum thickness when applying shotcrete.
- Become part of the reinforcement in the shotcrete lining.
- Provide support for spilling, if needed, over the next excavation.
- Work equally well with machine mining or drill and shoot tunneling - no need for major investment in special equipment
- Are practical supports for a wide range of ground conditions.
- Can be erected within a few minutes by a small crew without special handling equipment.
Fabrication
Fabrication of Lattice Girders
1. Lattice girder segments shall be composed of a low alloy steel used for concrete reinforcement and intended for special applications where bending and welding are of importance. 2. Minimum physical properties of steel:- Tensile strength minimum of 80 ksi
- Yield strength minimum of 70 ksi
- Ultimate elongation minimum of 10%