TYPES OF STRUCTURES USED IN CIVIL ENGINEERING

In civil engineering, a structure is defined as anything which is made up of various components which will resists external loading applied on them without  affecting the functions for which  the particular structure is designed.

 It is a very important task  for a structural engineers to select the type of structure which will be used in supporting or transmitting loads. On the basis of types of primary stresses which can be developed in a structure on the application of load, structures are classified in to five types:-

1. Tension carrying structures

2. Compression carrying structures

3. Trusses

4. Shear structures

5. Bending structures

The above mentioned structures can be considered as a basic types of structures. A single structure may be composed of combination of above mentioned structures.

TENSION STRUCTURES

These types of structures supports loading applied on them by generating tensile forces.

Some of the common types of tension structures we usually see are Cables, Vertical rods, etc.

Cables are usually used in supporting bridges. Vertical rods are used as hangers.

COMPRESSION STRUCTURES

These types of structures supports loading applied on them by generating compressive forces.

Some of the most common types of compressive structures we usually see are Columns and Arches.

Column is a straight member subjected to axially compressive loads while Arch is a curved structure. Column and Arches develops mainly compressive stresses on application of loads.

TRUSSES

These types of structures supports loading applied on them by developing axial forces. The axial forces generated can either be tensile or compressive in nature.

Trusses are generally composed of straight members with a pin connections at the ends. In real life , the trusses are generally constructed by connecting members to gusset plates by bolted or welded connections. This makes connections at the ends somewhat fixed and so induces some bending in the members of trusses. But as these secondary stresses are so small in magnitude, so that they can be neglected in design, and so the assumptions of pinned connections at the ends holds good.

Loading on trusses are only subjected to joints.

SHEAR STRUCTURES

These types of structures supports loading applied on them by developing mainly in-plane shear.

e.g. Reinforced concrete shear wall in multistorey buildings. This shear wall helps in reducing lateral movements of building due to wind loads and earthquake loads.

BENDING STRUCTURES

These types of structures supports external loadings applied on them by developing bending stresses.

Some of the most common types of  bending structures which we usually see are Beams, Rigid frames, Slabs. Beam is a straight member which is usually loaded perpendicular to its longitudional axes. Frames are composed of straight members connected together to support external loads applied on them. Unlike trusses , the loading on frames may be applied on joints as well as on members. In general a rigid frame develops bending moment, shear force and axial force also. But the design of horizontal members or beams of frames  is generally governed by bending and shear stresses only.