dead load

Dead load includes loads that are relatively constant over time, including the weight of the structure itself (called "own weight"), and immovable accessories such as walls, partitions or pavements. The roof or roof is also a dead load. They are also known as permanent or static loads. Construction materials are not considered dead loads until they are used in a construction and fixed in a permanent position.[8]​[9]​[10]​ Unit weights of various construction materials, parts and components are given in IS875 (Part 1)-1987.

live load

Live loads, or imposed loads, are temporary, short-duration, or moving loads. These dynamic loads may involve considerations such as impact, momentum, vibration, fluid dynamics, and material fatigue.

Live loads, sometimes also called probabilistic loads, include all forces that are variable within the normal operating cycle of the object, not including construction or environmental loads.

Roof and floor live loads are generated during maintenance by workers, equipment and materials, and during the life of the structure by moving objects, such as planters and people.

The live loads of a bridge are produced by pedestrians and vehicles traveling on its deck.

Environmental loads

Environmental loads are structural loads caused by natural forces such as wind, rain, snow, earthquakes, or extreme temperatures.

Other loads

Engineers must also be aware of other actions that can affect a structure, such as:.

Load combinations and safety factors

Load combination occurs when more than one type of load is considered to act simultaneously on a structure. Building codes generally specify various load combinations along with load coefficients (weightings) for each type of load to ensure the safety of the structure under different maximum expected load scenarios. For example, when designing a staircase, a dead load factor may be 1.2 times the weight of the structure, and a live load factor may be 1.6 times the maximum expected live load. These two "factored loads" are combined (added) to determine the "required strength" of the ladder.

The reason for the disparity between dead load and live load factors, that is, the reason why loads are initially classified as dead or live, is because while it is not unreasonable to expect a large number of people to climb the ladder at once, the structure is less likely to experience many changes in its permanent load.

dead load

Dead load includes loads that are relatively constant over time, including the weight of the structure itself (called "own weight"), and immovable accessories such as walls, partitions or pavements. The roof or roof is also a dead load. They are also known as permanent or static loads. Construction materials are not considered dead loads until they are used in a construction and fixed in a permanent position.[8]​[9]​[10]​ Unit weights of various construction materials, parts and components are given in IS875 (Part 1)-1987.

live load

Live loads, or imposed loads, are temporary, short-duration, or moving loads. These dynamic loads may involve considerations such as impact, momentum, vibration, fluid dynamics, and material fatigue.

Live loads, sometimes also called probabilistic loads, include all forces that are variable within the normal operating cycle of the object, not including construction or environmental loads.

Roof and floor live loads are generated during maintenance by workers, equipment and materials, and during the life of the structure by moving objects, such as planters and people.

The live loads of a bridge are produced by pedestrians and vehicles traveling on its deck.

Environmental loads

Environmental loads are structural loads caused by natural forces such as wind, rain, snow, earthquakes, or extreme temperatures.

Other loads

Engineers must also be aware of other actions that can affect a structure, such as:.

Load combinations and safety factors

Load combination occurs when more than one type of load is considered to act simultaneously on a structure. Building codes generally specify various load combinations along with load coefficients (weightings) for each type of load to ensure the safety of the structure under different maximum expected load scenarios. For example, when designing a staircase, a dead load factor may be 1.2 times the weight of the structure, and a live load factor may be 1.6 times the maximum expected live load. These two "factored loads" are combined (added) to determine the "required strength" of the ladder.

The reason for the disparity between dead load and live load factors, that is, the reason why loads are initially classified as dead or live, is because while it is not unreasonable to expect a large number of people to climb the ladder at once, the structure is less likely to experience many changes in its permanent load.