Long span structure

1. Long Span Structure.
Structures with a span larger than 15-20 meters are regarded to as long span structure. For such a structures span is unable
to be achieved with ordinary RCC construction. Generally, long span result in flexible, column free internal spaces. To
reduces substructure costs and time to erect the structure. For example – Stadium, Exhibition halls, Storage spaces, etc.
Exhibition Hall (Flexibility). Storage Space (Large scale structure). Stadium (Visibility).
Loads acting onto a structural systems:
1. Dead load.
2. Live load.
3. Wind load.
4. Stress created by temperature difference.
5. Stress created by other form disruption including ground movement, vibrations, deformation or earthquake.

2. Materials used for various form of Structure.
1. Reinforced concrete including precast.
2. Metal.
3. Timber.
4. Metal / RC combination.
5. Plastic – coated textile material.
6. Fiber reinforced plastic.
Types of Long Span Structures.
1. Form active system.
2. Vector active system.
3. Section active system.
4. Surface active system.

3. 1. Form active structural system.
Foam active structural system is a system of flexible, non-rigid matter, in which the redirection of forces is effected by
particular form design and characteristic form stabilization.
1. Cable structures.
2. Tent structures.
3. Pneumatic structures.
4. Arch structures.
Example of structures:

5. Examples of arch structure

6. 2. Vector active structural system.
Vector active structural system is system of short, solid, straight linear members in which the redirection of forces is effected
by vector partition, i.e. by multidirectional splitting of single force simply to tension or compressive elements.
Example of structures:
1. Flat trusses.
2. Curved trusses.
3. Space trusses.
1. Flat trusses.
Flat trusses also known as parallel – chord. The flat trusses are also used as a girders. Flat trusses are used to construct flat roof.

7. 2. Curved truss system.
Curved trusses are the trusses which are used to give a particular form to the building. The material mostly used is steel for
such construction. Curved roofs may be formed using single-curved tubular members or double layer members connected
periodically.
3. Space trusses.
Space truss is a rigid, lightweight, truss-like structure constructed
from interlocking struts in a geometric pattern. Space frame or
truss can be used to span large area with few internal supports.
Flexing load i.e. bending moment are transmitted as tension and
compression loads along the length of each strut.

8. 3. Section active structural system.
Section active structural system is a system of rigid, solid, linear elements in which redirection forces are effected by
mobilization of sectional forces.
Examples of Structures:
1. Beam structures.
2. Slab structures.
3. Frame structures.
1 & 2 bay beams 1 & 2 bay frames
Beam grid system Slab grid system
Frame structural system

9. 4. Surface active structural system.
Surface active structural system is a system of flexible or rigid planes able to resist tension, compression or shear in which the
redirection of forces are effected by mobilization of sectional forces.
Example of Structures:
1. Plate structure.
2. Folded structure.
3. Shell structure.
Plate structure Folded plate structure Shell structure
Sakshi Gadakh.
4th Year B.Arch.