Trenches in the construction industry - Revision history

Designing Buildings at 07:36, 10 December 2020

2020-12-10T07:36:43Z

← Older revision		Revision as of 07:36, 10 December 2020
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	* Substructure.		* Substructure.

−	[[Category:Construction_techniques]]	+	[[Category:DCN_Definition]] [[Category:DCN_Guidance]] [[Category:Construction_techniques]]

Designing Buildings: Reverted edits by 79.122.209.20 (talk) to last revision by Designing Buildings

2020-06-07T06:58:29Z

Reverted edits by 79.122.209.20 (talk) to last revision by Designing Buildings

← Older revision		Revision as of 06:58, 7 June 2020
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	* Sheet piles.		* Sheet piles.
	* Substructure.		* Substructure.
−
−	~~= External resources =~~
−
−	~~1. [https://safetyworkblog.com/templates/2020/05/17/Toolbox-Talk-Trenching.html Toolbox Talk Trenching]~~

	[[Category:Construction_techniques]]		[[Category:Construction_techniques]]

79.122.209.20 at 11:34, 6 June 2020

2020-06-06T11:34:51Z

← Older revision		Revision as of 11:34, 6 June 2020
Line 39:		Line 39:
	* Sheet piles.		* Sheet piles.
	* Substructure.		* Substructure.
		+
		+	= External resources =
		+
		+	1. [https://safetyworkblog.com/templates/2020/05/17/Toolbox-Talk-Trenching.html Toolbox Talk Trenching]

	[[Category:Construction_techniques]]		[[Category:Construction_techniques]]

Designing Buildings: moved Trench to Trenches in the construction industry

2019-12-27T11:54:31Z

moved Trench to Trenches in the construction industry

← Older revision

Revision as of 11:54, 27 December 2019

Designing Buildings at 10:19, 5 September 2019

2019-09-05T10:19:54Z

← Older revision		Revision as of 10:19, 5 September 2019
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−	A trench is a hollow cut into the ground, usually with parallel sides and which ~~typically~~ is deeper than it is wide. Trenches were used in the First World War as a means of conducting combat as they offered a degree of protection and cover from enemy fire.	+	A trench is a hollow cut into the ground, usually with parallel sides and which is typically deeper than it is wide. Trenches were used in the First World War as a means of conducting combat as they offered a degree of protection and cover from enemy fire.

	In construction, trenches are typically excavated for:		In construction, trenches are typically excavated for:

−	* Laying or getting access to services~~, and~~	+	* Laying or getting access to services.
−	* Constructing foundations eg strip foundations~~, basement foundations, diaphragm walls, etc~~.	+	* Constructing foundations such as strip foundations. For more information see: Strip foundation.

−	Trenches may be dug manually or by mechanical excavators, with spoil typically loaded onto dump trucks to be taken for disposal. They need to be constructed with care and must be adequately supported to prevent the sides from caving in, thereby causing a hazard to life, as well as resulting in unnecessary costs and delays to the project.	+	Trenches may be dug manually or by mechanical excavators, with spoil typically loaded onto dump trucks to be taken for disposal, or re-used elsewhere on site. They need to be constructed with care and must be adequately supported to prevent the sides from caving in, thereby causing a hazard to life, as well as resulting in unnecessary costs and delays to the project.

	For shallow trenches in firm ground, open timbering is usually used – whether made of timber or steel trench struts – in conjunction with poling boards. For softer ground, the number of poling boards is increased and they are arranged at closer intervals. Where the trench is deeper than 1.8m, or in loose soil, the sides are usually close-boarded.		For shallow trenches in firm ground, open timbering is usually used – whether made of timber or steel trench struts – in conjunction with poling boards. For softer ground, the number of poling boards is increased and they are arranged at closer intervals. Where the trench is deeper than 1.8m, or in loose soil, the sides are usually close-boarded.

	In deep trenches, especially where they are likely to be left open for any length of time, the pressures exerted by the trench sides onto the boarding are often considerable and there is the possibility of the sides caving in if not adequately supported. They may also fill with water following heavy rain which may cause structural problems and require a pump to evacuate the water.		In deep trenches, especially where they are likely to be left open for any length of time, the pressures exerted by the trench sides onto the boarding are often considerable and there is the possibility of the sides caving in if not adequately supported. They may also fill with water following heavy rain which may cause structural problems and require a pump to evacuate the water.
		+
		+	For more information see: Trench support and Dewatering.

	= Diaphragm walls =		= Diaphragm walls =

−	The construction of diaphragm walls often requires relatively narrow trenches to be cut – typically 500mm – 1,000mm wide and to depths of 50m and more. Excavation is typically undertaken using rope-suspended mechanical or hydraulically-operated grabs. ~~[[Diaphragm_wall\|See diaphragm wall.]]~~	+	The construction of diaphragm walls often requires relatively narrow trenches to be cut – typically 500mm – 1,000mm wide and to depths of 50m and more. Excavation is typically undertaken using rope-suspended mechanical or hydraulically-operated grabs.

	Preventing such deep, narrow trenches from caving in would be difficult using physical means such as struts and sheeting. Therefore, to provide support (before placing reinforcement and pouring the concrete) a bentonite slurry is poured into the trench. The slurry has thixotropic properties which means it is load bearing and so keeps the trench sides from collapsing. As the concrete is piped into the bottom of the trench, the bentonite is gradually displaced.		Preventing such deep, narrow trenches from caving in would be difficult using physical means such as struts and sheeting. Therefore, to provide support (before placing reinforcement and pouring the concrete) a bentonite slurry is poured into the trench. The slurry has thixotropic properties which means it is load bearing and so keeps the trench sides from collapsing. As the concrete is piped into the bottom of the trench, the bentonite is gradually displaced.
		+
		+	For more information see: Diaphragm wall.

	Trenches are often termed temporary works as they are only required for a portion of the construction process.		Trenches are often termed temporary works as they are only required for a portion of the construction process.
		+
		+	For more information see: Temporary works.

	= Related articles on Designing Buildings Wiki =		= Related articles on Designing Buildings Wiki =

Editor: Created page with "A trench is a hollow cut into the ground, usually with parallel sides and which typically is deeper than it is wide. Trenches were used in the First World War as a means of condu..."

2019-08-30T17:39:55Z

Created page with "A trench is a hollow cut into the ground, usually with parallel sides and which typically is deeper than it is wide. Trenches were used in the First World War as a means of condu..."

New page

A trench is a hollow cut into the ground, usually with parallel sides and which typically is deeper than it is wide. Trenches were used in the First World War as a means of conducting combat as they offered a degree of protection and cover from enemy fire.

In construction, trenches are typically excavated for:

* Laying or getting access to services, and
* Constructing foundations eg strip foundations, basement foundations, diaphragm walls, etc.

Trenches may be dug manually or by mechanical excavators, with spoil typically loaded onto dump trucks to be taken for disposal. They need to be constructed with care and must be adequately supported to prevent the sides from caving in, thereby causing a hazard to life, as well as resulting in unnecessary costs and delays to the project.

For shallow trenches in firm ground, open timbering is usually used – whether made of timber or steel trench struts – in conjunction with poling boards. For softer ground, the number of poling boards is increased and they are arranged at closer intervals. Where the trench is deeper than 1.8m, or in loose soil, the sides are usually close-boarded.

In deep trenches, especially where they are likely to be left open for any length of time, the pressures exerted by the trench sides onto the boarding are often considerable and there is the possibility of the sides caving in if not adequately supported. They may also fill with water following heavy rain which may cause structural problems and require a pump to evacuate the water.

= Diaphragm walls =

The construction of diaphragm walls often requires relatively narrow trenches to be cut – typically 500mm – 1,000mm wide and to depths of 50m and more. Excavation is typically undertaken using rope-suspended mechanical or hydraulically-operated grabs. [[Diaphragm_wall|See diaphragm wall.]]

Preventing such deep, narrow trenches from caving in would be difficult using physical means such as struts and sheeting. Therefore, to provide support (before placing reinforcement and pouring the concrete) a bentonite slurry is poured into the trench. The slurry has thixotropic properties which means it is load bearing and so keeps the trench sides from collapsing. As the concrete is piped into the bottom of the trench, the bentonite is gradually displaced.

Trenches are often termed temporary works as they are only required for a portion of the construction process.

= Related articles on Designing Buildings Wiki =

* Basement excavation.
* Building foundations.
* Curtain wall.
* Diaphragm walls
* Excavating plant.
* Ground anchor.
* Groundworks.
* Retaining walls.
* Secant pile wall.
* Sheet piles.
* Substructure.

[[Category:Construction_techniques]]