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and plumbing (MEP) equipment, and for buildings, it's common to include a Super
Imposed Dead Load (SIDL) of around 5 pounds per square foot (psf) accounting for miscellaneous weight such as bolts and other fasteners, cabling, and various fixtures or small architectural elements. Live loads, on the other hand, can be furniture, moveable equipment, or the people themselves, and may increase beyond normal or expected amounts in some situations, so a larger factor of 1.6 attempts to quantify this extra variability. Snow will also use a maximum factor of 1.6, while lateral loads (earthquakes and wind) are defined such that a 1.0 load factor is practical. Multiple loads may be added together in different ways, such as 1.2*Dead + 1.0*Live + 1.0*Earthquake + 0.2*Snow, or 1.2*Dead + 1.6(Snow, Live(roof), OR Rain) + (1.0*Live OR 0.5*Wind).
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216:(loads which are permanent and immovable excepting redesign or renovation) and wind load, as described below. In some cases structures may be subject to other loads, such as those due to earthquakes or pressures from retained material. The expected maximum magnitude of each is referred to as the characteristic load.
546:
The size of the load factor is based on the probability of exceeding any specified design load. Dead loads have small load factors, such as 1.2, because weight is mostly known and accounted for, such as structural members, architectural elements and finishes, large pieces of mechanical, electrical
295:
are, roughly, a ratio of the theoretical design strength to the maximum load expected in service. They are developed to help achieve the desired level of reliability of a structure based on probabilistic studies that take into account the load's originating cause, recurrence, distribution, and
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require that structures be designed and built to safely resist all actions that they are likely to face during their service life, while remaining fit for use. Minimum loads or actions are specified in these building codes for types of structures, geographic locations, usage and
288:. Structural loads are split into categories by their originating cause. In terms of the actual load on a structure, there is no difference between dead or live loading, but the split occurs for use in safety calculations or ease of analysis on complex models.
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a structure is expected to carry. These loads come in many different forms, such as people, equipment, vehicles, wind, rain, snow, earthquakes, the building materials themselves, etc. Specified loads also known as characteristic loads in many cases.
543:, 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 staircase.
379:
Live loads, sometimes also referred to as probabilistic loads, include all the forces that are variable within the object's normal operation cycle not including construction or environmental loads.
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loads a component or structure may carry safely. Ultimate loads are the limit loads times a factor of 1.5 or the point beyond which the component or structure will fail. Gust loads are determined
578:. Other loads that may be critical are pressure loads (for pressurized, high-altitude aircraft) and ground loads. Loads on the ground can be from adverse braking or maneuvering during
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Roof and floor live loads are produced during maintenance by workers, equipment and materials, and during the life of the structure by movable objects, such as planters and people.
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To meet the requirement that design strength be higher than maximum loads, building codes prescribe that, for structural design, loads are increased by load factors. These
271:
Imposed loads are those associated with occupation and use of the building; their magnitude is less clearly defined and is generally related to the use of the building.
539:(weightings) for each load type in order to ensure the safety of the structure under different maximum expected loading scenarios. For example, in designing a
332:. Building materials are not dead loads until constructed in permanent position. IS875(part 1)-1987 give unit weight of building materials, parts, components.
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The dead load includes loads that are relatively constant over time, including the weight of the structure itself, and immovable fixtures such as walls,
802:
EN 1991-1-1 Euro code 1: Actions on
Structures – Part 1-1: General actions – densities, self-weight, imposed loads for buildings section 3.2
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An impact load is one whose time of application on a material is less than one-third of the natural period of vibration of that material.
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106:—are subject to their own particular structural loads and actions. Engineers often evaluate structural loads based upon published
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Environmental loads are structural loads caused by natural forces such as wind, rain, snow, earthquake or extreme temperatures.
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82:, so this should be considered and controlled during the design of a structure. Particular mechanical structures—such as
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For aircraft, loading is divided into two major categories: limit loads and ultimate loads. Limit loads are the
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damage, cumulative damage, or failure. These loads can be repeated loadings on a structure or can be due to
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231:. The term can refer to a laboratory test method or to the normal usage of a material or structure.
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Buildings will be subject to loads from various sources. The principal ones can be classified as
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Fisette, Paul, and the
American Wood Council. "Understanding Loads and Using Span Tables". 1997.
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Luebkeman, Chris H., and Donald
Petting "Lecture 17: Primary Loads". University of Oregon. 1996
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830:, Volume 1, ed. I. M. Allison (Rotterdam, Netherlands: A.A. Balkema Publishers, 1998), p. 379
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238:. These can have a significant dynamic element and may involve considerations such as
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582:. Aircraft are constantly subjected to cyclic loading. These cyclic loads can cause
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Engineers must also be aware of other actions that may affect a structure, such as:
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Bridge live loads are produced by vehicles traveling over the deck of the bridge.
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A load combination results when more than one load type acts on the structure.
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Structural loads are an important consideration in the design of buildings.
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328:. The roof is also a dead load. Dead loads are also known as permanent or
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168: in this section. Unsourced material may be challenged and removed.
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ASCE/SEI 7-05 Minimum Design Loads for
Buildings and Other Structures
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Live loads, or imposed loads, are temporary, of short duration, or a
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that are relatively constant for an extended time. They can be in
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Mechanical loads (forces) applied to a structure or its components
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Experimental
Mechanics: Advances in Design, Testing and Analysis
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843:(Cambridge; New York: Cambridge University Press, 2008), p. 129
818:(Cambridge; New York: Cambridge University Press, 2008), p. 126
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usually specify a variety of load combinations together with
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EN 1990 Euro code – Basis of structural design section 4.1.1
749:. Bruxelles: European Committee for Standardization. 2002.
709:. Bruxelles: European Committee for Standardization. 2002.
669:. Bruxelles: European Committee for Standardization. 2002.
644:. American Society of Civil Engineers. 2006. p. 1.
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Loads on architectural and civil engineering structures
212:(loads which are not always present in the structure),
724:. USA: International Code Council. 2000. p. 295.
200:, specified loads are the best estimate of the actual
682:Mark's Standard Handbook for Mechanical Engineers
841:Analysis of Aircraft Structures: An Introduction
816:Analysis of Aircraft Structures: An Introduction
784:2006 International Building Code Section 1602.1.
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747:Eurocode 0: Basis of structural design EN 1990
707:Eurocode 0: Basis of structural design EN 1990
684:(10th ed.). McGraw-Hill. pp. 11–42.
667:Eurocode 0: Basis of structural design EN 1990
8:
516:Impact from vehicles or machinery vibration
563:and are provided by an agency such as the
356:loads may involve considerations such as
184:Learn how and when to remove this message
260:Cyclic loads on a structure can lead to
680:Avallone, E.A.; Baumeister, T. (eds.).
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764:. USA: McGraw-Hill. pp. 214–227.
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166:adding citations to reliable sources
234:Live loads are usually variable or
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565:Federal Aviation Administration
153:needs additional citations for
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722:International Building Code
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760:Rao, Singiresu S. (1992).
551:Aircraft structural loads
762:Reliability Based Design
596:Hotel New World disaster
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372:of fluids and material
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883:Building engineering
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607:Probabilistic design
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429:changes leading to
389:Environmental loads
120:technical standards
72:Structural analysis
48:structural elements
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286:building materials
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160:Please help
155:verification
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118:. Accepted
64:acceleration
60:displacement
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665:"1.5.3.1".
571:of a major
478:Other loads
456:groundwater
427:Temperature
350:moving load
229:compression
108:regulations
76:engineering
56:deformation
867:Categories
720:"1604.2".
628:References
490:settlement
487:Foundation
473:Dust loads
468:Permafrost
406:Wind loads
214:dead loads
210:live loads
174:April 2024
128:inspection
104:submarines
88:satellites
18:Rated load
541:staircase
506:Explosion
501:Corrosion
366:vibration
336:Live load
316:Dead load
308:Dead load
266:vibration
248:vibration
112:contracts
68:structure
590:See also
362:momentum
352:. These
304:nature.
244:momentum
84:aircraft
580:taxiing
557:maximum
470:melting
440:Ponding
374:fatigue
354:dynamic
302:dynamic
262:fatigue
225:tension
92:rockets
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576:impact
573:ground
463:floods
433:cause
358:impact
326:carpet
298:static
240:impact
102:, and
52:stress
522:loads
511:Creep
442:loads
202:loads
134:Types
114:, or
100:ships
66:in a
44:force
38:is a
766:ISBN
726:ISBN
686:ISBN
646:ISBN
496:Fire
452:soil
411:Snow
126:and
324:or
300:or
227:or
196:In
164:by
62:or
34:or
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