Span - Revision history

Designing Buildings at 06:44, 5 February 2025

2025-02-05T06:44:46Z

← Older revision		Revision as of 06:44, 5 February 2025
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	In structural engineering and architecture, ‘span’ is the term given to the length of a structural component – eg beam, floor, roof or floor truss – that extends (or ‘spans’) between two supports. Thus, a beam may be supported at either end, in which case it is said to span between the two points, and a floor may span between two (or three or even four) continuous supports.		In structural engineering and architecture, ‘span’ is the term given to the length of a structural component – eg beam, floor, roof or floor truss – that extends (or ‘spans’) between two supports. Thus, a beam may be supported at either end, in which case it is said to span between the two points, and a floor may span between two (or three or even four) continuous supports.
		+
		+	Approved document A: Structure, 2004 edition incorporating 2004, 2010 and 2013 amendments, defines span as: ‘The distance measured along the centre line of a member between the centres of any two adjacent bearings or supports.’

	A general engineering principle is the longer the span, the deeper the structural component will have to be to safely support its self-weight and whatever it must carry, eg a floor.		A general engineering principle is the longer the span, the deeper the structural component will have to be to safely support its self-weight and whatever it must carry, eg a floor.
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	In bridge design, span/depth ratio is an important parameter. The ratio relates the length of the bridge’s span to its girder depth. To ensure that design does not deviate substantially from past successful practice, the ratio is commonly chosen on the basis of experience and the typical values used on past bridges. A typical starting point for estimating bridge construction depths is to take an STD ratio of 20.		In bridge design, span/depth ratio is an important parameter. The ratio relates the length of the bridge’s span to its girder depth. To ensure that design does not deviate substantially from past successful practice, the ratio is commonly chosen on the basis of experience and the typical values used on past bridges. A typical starting point for estimating bridge construction depths is to take an STD ratio of 20.

−	= Related articles on Designing Buildings ~~Wiki~~ =	+	= Related articles on Designing Buildings =

	* Concept structural design of buildings.		* Concept structural design of buildings.
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	* Elements of structure in buildings		* Elements of structure in buildings
	* Institution of Structural Engineers IStructE.		* Institution of Structural Engineers IStructE.
		+	* Spacing.
	* Structural principles.		* Structural principles.
	* Structures at the end of their design life.		* Structures at the end of their design life.
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	* Superstructure.		* Superstructure.
	* The development of structural membranes.		* The development of structural membranes.
−	* ~~Tower~~.	+	* Tolerance.
	* Types of structure.		* Types of structure.

	[[Category:DCN_Definition]] [[Category:DCN_Guidance]] [[Category:Education]] [[Category:Theory]] [[Category:Design]]		[[Category:DCN_Definition]] [[Category:DCN_Guidance]] [[Category:Education]] [[Category:Theory]] [[Category:Design]]

Designing Buildings at 05:13, 22 October 2020

2020-10-22T05:13:56Z

← Older revision		Revision as of 05:13, 22 October 2020
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	* Types of structure.		* Types of structure.

−	[[Category:~~Education~~]] [[Category:~~DCN_Education_and_Training~~]] [[Category:Theory]] [[Category:Design]]	+	[[Category:DCN_Definition]] [[Category:DCN_Guidance]] [[Category:Education]] [[Category:Theory]] [[Category:Design]]

Designing Buildings at 15:01, 27 March 2019

2019-03-27T15:01:14Z

← Older revision		Revision as of 15:01, 27 March 2019
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	= Span-to-depth (STD) ratio =		= Span-to-depth (STD) ratio =

−	Span-to-depth ratio (or span/depth ratio, also known as slenderness ratio L/h) is the ratio of the span length divided by the depth (or vertical height) of ~~the~~ component. It is an important parameter as it can affect structural behaviour, construction costs and aesthetics.	+	Span-to-depth ratio (or span/depth ratio, also known as slenderness ratio L/h) is the ratio of the span length divided by the depth (or vertical height) of a component. It is an important parameter as it can affect structural behaviour, construction costs and aesthetics.

	A 250mm-deep beam that spans 4m has a span/depth ratio of 16. If the span/depth ratio is less than two, the beam is considered to be ‘deep’. Eurocode 2 gives span/depth rules for designing reinforced concrete beams and slabs.		A 250mm-deep beam that spans 4m has a span/depth ratio of 16. If the span/depth ratio is less than two, the beam is considered to be ‘deep’. Eurocode 2 gives span/depth rules for designing reinforced concrete beams and slabs.
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	Span/depth ratios are useful in limiting the deflection of a member under service loads. Damage may result if limits are exceeded, eg cracking of plaster, partitions and supporting brickwork. If limits are exceeded wildly, catastrophic structural failure accompanied by potential loss of life may result.		Span/depth ratios are useful in limiting the deflection of a member under service loads. Damage may result if limits are exceeded, eg cracking of plaster, partitions and supporting brickwork. If limits are exceeded wildly, catastrophic structural failure accompanied by potential loss of life may result.

−	In bridge design, span/depth ratio is an important parameter. The ratio relates the length of the bridge’s span to its girder depth ~~and is usually used to establish the depth of the superstructure~~. To ensure that design does not deviate substantially from past successful practice, the ratio is commonly chosen on the basis of experience and the typical values used on past bridges. A typical starting point for estimating bridge construction depths is to take an STD ratio of 20.	+	In bridge design, span/depth ratio is an important parameter. The ratio relates the length of the bridge’s span to its girder depth. To ensure that design does not deviate substantially from past successful practice, the ratio is commonly chosen on the basis of experience and the typical values used on past bridges. A typical starting point for estimating bridge construction depths is to take an STD ratio of 20.

	= Related articles on Designing Buildings Wiki =		= Related articles on Designing Buildings Wiki =
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	* Types of structure.		* Types of structure.

−	[[Category:Education]] [[Category:Theory]] [[Category:Design]]	+	[[Category:Education]] [[Category:DCN_Education_and_Training]] [[Category:Theory]] [[Category:Design]]

Editor: Created page with "= Introduction = In structural engineering and architecture, ‘span’ is the term given to the length of a structural component – eg beam, floor, roof or floor truss – tha..."

2019-03-26T18:39:57Z

Created page with "= Introduction = In structural engineering and architecture, ‘span’ is the term given to the length of a structural component – eg beam, floor, roof or floor truss – tha..."

New page

= Introduction =

In structural engineering and architecture, ‘span’ is the term given to the length of a structural component – eg beam, floor, roof or floor truss – that extends (or ‘spans’) between two supports. Thus, a beam may be supported at either end, in which case it is said to span between the two points, and a floor may span between two (or three or even four) continuous supports.

A general engineering principle is the longer the span, the deeper the structural component will have to be to safely support its self-weight and whatever it must carry, eg a floor.

= Span-to-depth (STD) ratio =

Span-to-depth ratio (or span/depth ratio, also known as slenderness ratio L/h) is the ratio of the span length divided by the depth (or vertical height) of the component. It is an important parameter as it can affect structural behaviour, construction costs and aesthetics.

A 250mm-deep beam that spans 4m has a span/depth ratio of 16. If the span/depth ratio is less than two, the beam is considered to be ‘deep’. Eurocode 2 gives span/depth rules for designing reinforced concrete beams and slabs.

More dramatic span/depth ratios can be provided by space frames: a rectangular space frame may have a span/depth ratio of up to 40, while this can be as high as 60 for a skew space frame.

Span/depth ratios are useful in limiting the deflection of a member under service loads. Damage may result if limits are exceeded, eg cracking of plaster, partitions and supporting brickwork. If limits are exceeded wildly, catastrophic structural failure accompanied by potential loss of life may result.

In bridge design, span/depth ratio is an important parameter. The ratio relates the length of the bridge’s span to its girder depth and is usually used to establish the depth of the superstructure. To ensure that design does not deviate substantially from past successful practice, the ratio is commonly chosen on the basis of experience and the typical values used on past bridges. A typical starting point for estimating bridge construction depths is to take an STD ratio of 20.

= Related articles on Designing Buildings Wiki =

* Concept structural design of buildings.
* Deflection.
* Elements of structure in buildings
* Institution of Structural Engineers IStructE.
* Structural principles.
* Structures at the end of their design life.
* Substructure.
* Superstructure.
* The development of structural membranes.
* Tower.
* Types of structure.

[[Category:Education]] [[Category:Theory]] [[Category:Design]]