Classification of Loads on Structures

For B. Tech First Year Students

1. TYPES OF LOADS ON STRUCTURE Dr. Mohd . Zameeruddin Mohd . Saleemuddin Assistant professor, Department of Civil Engineering, MGM’s College of Engineering, Nanded ( m.s ) © mzs engineering technologies Email: [email protected]; [email protected]

2. The loads are broadly classified as; Vertical loads, Horizontal loads, and Longitudinal loads. The vertical loads consist of dead load, live load and impact load. The horizontal loads comprises of wind load and earthquake load. The longitudinal loads i.e. tractive and braking forces are considered in special case of design of bridges, gantry girders etc. Classification of Loads

3. Structural loads A load may be defined as a force tending to effect and produce deformations, stresses or displacements in the structure Compression Tension Shear

4. Types of Loads in Structures Dead loads Live loads Dynamic loads Wind loads Earthquake loads Snow loads

5. Dead load Dead loads are permanent or stationary loads which are transferred to structure throughout the life span. Dead load is primarily due to self weight of structural members, permanent partition walls, fixed permanent equipment's and weight of different materials.

6. Imposed loads or live loads Live loads are either movable or moving loads with out any acceleration or impact. There are assumed to be produced by the intended use or occupancy of the building including weights of movable partitions or furniture etc.

7. Snow loads The amount of snow load on a roof structure is dependent on a variety of factors; Roof geometry, Size of the structure, Insulation of the structure, Wind frequency, Snow duration, Geographical location of the structure.

8. Impact loads Impact load is caused by vibration or impact or acceleration. Thus, impact load is equal to imposed load incremented by some percentage called impact factor or impact allowance depending upon the intensity of impact.

9. Earthquake load (Seismic load) Earthquake loads are horizontal loads caused by the earthquake and shall be computed in accordance with IS 1893. For monolithic reinforced concrete structures located in the seismic zone 2, and 3 without more than 5 storey high and importance factor less than 1, the seismic forces are not critical.

10. Wind loads Wind load is primarily horizontal load caused by the movement of air relative to earth. Wind load is required to be considered in design especially when the heath of the building exceeds two times the dimensions transverse to the exposed wind surface.

11. Wind loads The amount of wind load is dependent on the following; Geographical location The height of structure Type of surrounding physical environment The shape of structure Size of the building