1D Bridges - Revision history

Anne.Kolega: /* Irregular Shaped Bridges */ i.e.

2026-04-02T01:47:12Z

Irregular Shaped Bridges: i.e.

← Older revision		Revision as of 11:47, 2 April 2026
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	To create an irregular shaped bridge:		To create an irregular shaped bridge:
	<ol>		<ol>
	<li>Create a 1d_tab HW (height vs width) .csv file for each standard shape (ie. set up a database of the irregular shapes). For the height value you can start at a value of zero so that height becomes depth (this might making the .csv files easier). As the height increases the width changes to reflect the particular irregular shape you are modeling. In the example below, the width at the top of the arch (2.1m) is set to a small value of 0.001m as opposed to zero as the HW becomes NA past the top of the irregular shape. <br>		<li>Create a 1d_tab HW (height vs width) .csv file for each standard shape (i.e. set up a database of the irregular shapes). For the height value you can start at a value of zero so that height becomes depth (this might making the .csv files easier). As the height increases the width changes to reflect the particular irregular shape you are modeling. In the example below, the width at the top of the arch (2.1m) is set to a small value of 0.001m as opposed to zero as the HW becomes NA past the top of the irregular shape. <br>

	[[File:HW_arch_example.JPG\|border\|900px]] <br>		[[File:HW_arch_example.JPG\|border\|900px]] <br>
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	[[File:Irregular_culvert_attribute_details.JPG\|border\|500px]]<br>		[[File:Irregular_culvert_attribute_details.JPG\|border\|500px]]<br>
	<br>		<br>
	<li>Any number of 1d_tab lines can reference the same .csv file, ie. you don't need to have a unique .csv file for every 1d_tab line. <br>		<li>Any number of 1d_tab lines can reference the same .csv file, i.e. you don't need to have a unique .csv file for every 1d_tab line. <br>
	[[File:Arch HW attributes.JPG\|border\|300px]] <br>		[[File:Arch HW attributes.JPG\|border\|300px]] <br>
	<br>		<br>

Emilie Nielsen: /* Introduction */

2026-03-02T02:28:06Z

Introduction

← Older revision		Revision as of 12:28, 2 March 2026
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	=Introduction=		=Introduction=
	The following section looks at bridges using the 1D component of TUFLOW. For information on bridges in the 2D domain see <u>[[TUFLOW_2D_Hydraulic_Structures \| 2D Hydraulic Structures]]</u> and <u>[[Tutorial M04\|Tutorial M04 - Tuflow]]</u>. ~~For~~ 1D ~~and 2D~~ bridges in ~~example~~ ~~models~~ ~~please~~ ~~also~~ ~~see~~ [[TUFLOW Example Models#Structures\|TUFLOW Example ~~Models -~~ ~~Tuflow~~]].<br>		The following section looks at bridges using the 1D component of TUFLOW. For information on bridges in the 2D domain see <u>[[TUFLOW_2D_Hydraulic_Structures \| 2D Hydraulic Structures]]</u> and <u>[[Tutorial M04\|Tutorial M04 - Tuflow]]</u>. Example models using bridges in 1D and 2D are available in the [[TUFLOW Example Models#Structures\|TUFLOW Example Model Dataset]].<br>

	'''Example of a bridge that could be modelled in 1D'''		'''Example of a bridge that could be modelled in 1D'''
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	Care must be taken when choosing the approach to modelling the bridge and setting appropriate loss values. <br>		Care must be taken when choosing the approach to modelling the bridge and setting appropriate loss values. <br>
	<br>		<br>

	=1D Bridge Channel Types=		=1D Bridge Channel Types=
	TUFLOW offers two 1D bridge channels, B and BB. BB channels were introduced for Build 2016-03-AA and are a more advanced solution than B channels, which are retained for legacy models. By default, BB channels are superior to B channels as they:<br>		TUFLOW offers two 1D bridge channels, B and BB. BB channels were introduced for Build 2016-03-AA and are a more advanced solution than B channels, which are retained for legacy models. By default, BB channels are superior to B channels as they:<br>

Anne.Kolega: /* Introduction */ added link to example model and updated M11 to M04 for 2D bridge

2026-02-24T03:38:03Z

Introduction: added link to example model and updated M11 to M04 for 2D bridge

← Older revision		Revision as of 13:38, 24 February 2026
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	=Introduction=		=Introduction=
	The following section looks at bridges using the 1D component of TUFLOW. For information on bridges in the 2D domain see <u>[[TUFLOW_2D_Hydraulic_Structures \| 2D Hydraulic Structures]]</u> and <u>[[~~Tutorial_M11#Part_2_-_1D_Open_Channel_with_1D_Bridges_and_Weir_inflow_.282D.29_and_Outflow_.281D.29~~ \| ~~Module~~ 11]]</u>. <br>		The following section looks at bridges using the 1D component of TUFLOW. For information on bridges in the 2D domain see <u>[[TUFLOW_2D_Hydraulic_Structures \| 2D Hydraulic Structures]]</u> and <u>[[Tutorial M04\|Tutorial M04 - Tuflow]]</u>. For 1D and 2D bridges in example models please also see [[TUFLOW Example Models#Structures\|TUFLOW Example Models - Tuflow]].<br>

	'''Example of a bridge that could be modelled in 1D'''		'''Example of a bridge that could be modelled in 1D'''

Emilie Nielsen at 00:24, 23 September 2024

2024-09-23T00:24:56Z

← Older revision		Revision as of 10:24, 23 September 2024
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	=Introduction=		=Introduction=
	The following section looks at bridges using the 1D component of TUFLOW~~. Reference should also be made to Section 5.7.2 of the <u>[https://downloads.tuflow.com/_archive/TUFLOW/Releases/2018-03/TUFLOW%20Manual.2018-03.pdf 2018 TUFLOW Manual]</u>~~. For information on bridges in the 2D domain see <u>[[TUFLOW_2D_Hydraulic_Structures \| 2D Hydraulic Structures]]</u> and <u>[[Tutorial_M11#Part_2_-_1D_Open_Channel_with_1D_Bridges_and_Weir_inflow_.282D.29_and_Outflow_.281D.29 \| Module 11]]</u>. <br>		The following section looks at bridges using the 1D component of TUFLOW. For information on bridges in the 2D domain see <u>[[TUFLOW_2D_Hydraulic_Structures \| 2D Hydraulic Structures]]</u> and <u>[[Tutorial_M11#Part_2_-_1D_Open_Channel_with_1D_Bridges_and_Weir_inflow_.282D.29_and_Outflow_.281D.29 \| Module 11]]</u>. <br>

	'''Example of a bridge that could be modelled in 1D'''		'''Example of a bridge that could be modelled in 1D'''
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	:*automatically simulates pressure flow conditions. The only loss coefficients required to be specified for BB channels are those due to piers, and the bridge deck when it is submerged and not under pressure flow.		:*automatically simulates pressure flow conditions. The only loss coefficients required to be specified for BB channels are those due to piers, and the bridge deck when it is submerged and not under pressure flow.

	Adjustment of losses according to approach/departure velocities is the default from 1D channel to 1D bridge to 1D channel. However, for TUFLOW Builds prior to 2020-10-AA, if the BB bridge is linked directly to a 2D domain (typically via a SX link), there is no adjustment of entrance / exit losses on the sides connected to the 2D. This capability was introduced for 2D channel to 1D bridge to 2D channel in Build 2020-10-AA and onwards, and losses can be automatically adjusted based on the approach/departure 2D velocities across the SX connections by setting "<font color="blue"><tt>Structure Losses SX</tt></font> <font color="red"><tt>==</tt></font><tt> ADJUST</tt>" (see Section 6.2 of the <u>[https://downloads.tuflow.com/TUFLOW/Releases/2020-10/TUFLOW%20Release%20Notes.2020-10-AF.pdf 2020-10 Release Note]</u>). For B bridges the default is not to adjust losses (refer to the <u>[https://~~downloads~~.tuflow.com/~~_archive~~/~~TUFLOW~~/~~Releases~~/~~2018-03/TUFLOW%20Manual.2018-03.pdf 2018~~ TUFLOW Manual]</u> for more information). In the case of 2D connections, refer to the links below for a discussion on the intricacies and challenges of taking into account contraction and expansion losses for 1D structures connected directly to 2D domains:		Adjustment of losses according to approach/departure velocities is the default from 1D channel to 1D bridge to 1D channel. However, for TUFLOW Builds prior to 2020-10-AA, if the BB bridge is linked directly to a 2D domain (typically via a SX link), there is no adjustment of entrance / exit losses on the sides connected to the 2D. This capability was introduced for 2D channel to 1D bridge to 2D channel in Build 2020-10-AA and onwards, and losses can be automatically adjusted based on the approach/departure 2D velocities across the SX connections by setting "<font color="blue"><tt>Structure Losses SX</tt></font> <font color="red"><tt>==</tt></font><tt> ADJUST</tt>" (see Section 6.2 of the <u>[https://downloads.tuflow.com/TUFLOW/Releases/2020-10/TUFLOW%20Release%20Notes.2020-10-AF.pdf 2020-10 Release Note]</u>). For B bridges the default is not to adjust losses (refer to the <u>[https://docs.tuflow.com/classic-hpc/manual/latest/ TUFLOW Manual]</u> for more information). In the case of 2D connections, refer to the links below for a discussion on the intricacies and challenges of taking into account contraction and expansion losses for 1D structures connected directly to 2D domains:
	:*<u>[https://www.tuflow.com/Download/Presentations/2012/2012%20Aust%20Workshops%20-%20TUFLOW%20Modelling%20Bends,%20Structures%20and%20Obstructions.pdf 1D and 2D Modelling Bends, Structures and Obstructions]</u>		:*<u>[https://www.tuflow.com/Download/Presentations/2012/2012%20Aust%20Workshops%20-%20TUFLOW%20Modelling%20Bends,%20Structures%20and%20Obstructions.pdf 1D and 2D Modelling Bends, Structures and Obstructions]</u>
	:*<u>[https://www.tuflow.com/Download/Publications/Modelling%20of%20Bends%20and%20Hydraulic%20Structures%20in%20a%202D%20Scheme,%20Syme,%202001.pdf Modelling of Bends and Hydraulic Structures in a Two-Dimensional Scheme]</u>		:*<u>[https://www.tuflow.com/Download/Publications/Modelling%20of%20Bends%20and%20Hydraulic%20Structures%20in%20a%202D%20Scheme,%20Syme,%202001.pdf Modelling of Bends and Hydraulic Structures in a Two-Dimensional Scheme]</u>

Abigail.lillo: /* Check Files */

2024-07-25T04:27:10Z

Check Files

← Older revision		Revision as of 14:27, 25 July 2024
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	\|}		\|}

	<br><br><br><br><br><br><br><br>		<br><br><br><br><br><br><br><br><br><br>
	<br><br><br><br><br><br><br><br>		<br><br><br><br><br><br><br><br><br>

	Any further questions please email TUFLOW support: [mailto:support@tuflow.com?Subject=TUFLOW%201D%20bridges%20help support@tuflow.com]		Any further questions please email TUFLOW support: [mailto:support@tuflow.com?Subject=TUFLOW%201D%20bridges%20help support@tuflow.com]
	<br><br>		<br><br>


	{{Tips Navigation		{{Tips Navigation
	\|uplink=[[ TUFLOW 1D Channels and Hydraulic Structures \| Back to 1D Channels and Hydraulic Structures]]		\|uplink=[[ TUFLOW 1D Channels and Hydraulic Structures \| Back to 1D Channels and Hydraulic Structures]]

ElizaCollison: /* Check Files */

2023-01-03T21:41:25Z

Check Files

← Older revision		Revision as of 07:41, 4 January 2023
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	<br><br>		<br><br>
	{{Tips Navigation		{{Tips Navigation
	\|uplink=[[ ~~TUFLOW_1D_Hydraulic_Structures~~ \| Back to 1D Hydraulic Structures]]		\|uplink=[[ TUFLOW 1D Channels and Hydraulic Structures \| Back to 1D Channels and Hydraulic Structures]]
	}}		}}

ElizaCollison: /* Deck Losses and Pressure Flow */

2023-01-03T03:25:54Z

Deck Losses and Pressure Flow

← Older revision		Revision as of 13:25, 3 January 2023
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	A pressure flow condition can occur when the water level reaches the bridge deck level (as water is forced through a small opening confined by the bridge abutments and the deck), resulting in additional energy losses. As the bridge becomes totally drowned by the water level, the condition will switch back to the normal submerged bridge deck flow condition. To account for this, once water reaches the height of the bridge deck, the TUFLOW BB bridge tests for either the pressure flow condition or drowned flow condition at every timestep by choosing the flow regime that gives the lower flow:		A pressure flow condition can occur when the water level reaches the bridge deck level (as water is forced through a small opening confined by the bridge abutments and the deck), resulting in additional energy losses. As the bridge becomes totally drowned by the water level, the condition will switch back to the normal submerged bridge deck flow condition. To account for this, once water reaches the height of the bridge deck, the TUFLOW BB bridge tests for either the pressure flow condition or drowned flow condition at every timestep by choosing the flow regime that gives the lower flow:
	:*The pressure flow equation is based on the Section 8.3 of the <u>[https://www.fhwa.dot.gov/engineering/hydraulics/pubs/hds1.pdf Hydraulics of Bridge Waterways (Bradley, 1978)]</u>, with a default deck discharge coefficient of 0.8. This value can be modified using the 1d_nwk HConF_or_WC attribute. Note that the original hydraulic experiment conducted by Liu (1967) used a flume with a pair of bridge abutments and a deck. This means the impact of both abutments and deck are considered in this approach. The entry/exit losses are switched off during the pressure flow calculation to avoid the overestimation of the contraction/expansion losses.		:*The pressure flow equation is based on the Section 8.3 of the <u>[https://www.fhwa.dot.gov/engineering/hydraulics/pubs/hds1.pdf Hydraulics of Bridge Waterways (Bradley, 1978)]</u>, with a default deck discharge coefficient of 0.8. This value can be modified using the 1d_nwk HConF_or_WC attribute. Note that the original hydraulic experiment conducted by Liu (1967) used a flume with a pair of bridge abutments and a deck. This means the impact of both abutments and deck are considered in this approach. The entry/exit losses are switched off during the pressure flow calculation to avoid the overestimation of the contraction/expansion losses.
	:*For the drowned flow condition, the BB bridge considers extra energy loss caused by the bridge deck/rails using a deck loss coefficient (default = 0.5) in addition to the entry/exit losses. The deck loss coefficient can be adjusted using the WConF_or_WEx attribute or by specifying the LC (energy loss versus height) table.		:*For the drowned flow condition, the BB bridge considers extra energy loss caused by the bridge deck/rails using a deck loss coefficient (default = 0.5) in addition to the entry/exit losses. The deck loss coefficient can be adjusted using the WConF_or_WEx attribute or by specifying the LC (energy loss versus height) table. <br>

	When pressure flow occurs a flow regime of "P" is reported in the _TSF layer. <br>
			The _TSF and _TSL layers can be used to find out the regime/form loss values used for BB bridges:
			*"P": pressure flow
			*"D": ds water level > the soffit level, but it applies normal flow because the normal flow equation predicts smaller velocity
			*" ": ds water level < the soffit level, normal flow

	For the legacy B channels, the deck loss coefficient was fixed at a value of 1.5625, which is derived from the discharge coefficient in Hydraulics of Bridge Waterways of 0.8 (1.56 = 1/0.8^2) to approximate pressure flow conditions. Whilst this is reasonable when the bridge deck experiences pressure flow, it will over-estimate the losses once the bridge deck starts to drown out and flow returns fully to downstream controlled.<br>		For the legacy B channels, the deck loss coefficient was fixed at a value of 1.5625, which is derived from the discharge coefficient in Hydraulics of Bridge Waterways of 0.8 (1.56 = 1/0.8^2) to approximate pressure flow conditions. Whilst this is reasonable when the bridge deck experiences pressure flow, it will over-estimate the losses once the bridge deck starts to drown out and flow returns fully to downstream controlled.<br>

ElizaCollison at 01:50, 3 January 2023

2023-01-03T01:50:21Z

← Older revision		Revision as of 11:50, 3 January 2023
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	<font size = 18>Page Under Construction</font>
	<br>
	<br>
	<br>
	=Introduction=		=Introduction=
	The following section looks at bridges using the 1D component of TUFLOW. Reference should also be made to Section 5.7.2 of the <u>[https://downloads.tuflow.com/_archive/TUFLOW/Releases/2018-03/TUFLOW%20Manual.2018-03.pdf 2018 TUFLOW Manual]</u>. For information on bridges in the 2D domain see <u>[[TUFLOW_2D_Hydraulic_Structures \| 2D Hydraulic Structures]]</u> and <u>[[Tutorial_M11#Part_2_-_1D_Open_Channel_with_1D_Bridges_and_Weir_inflow_.282D.29_and_Outflow_.281D.29 \| Module 11]]</u>. <br>		The following section looks at bridges using the 1D component of TUFLOW. Reference should also be made to Section 5.7.2 of the <u>[https://downloads.tuflow.com/_archive/TUFLOW/Releases/2018-03/TUFLOW%20Manual.2018-03.pdf 2018 TUFLOW Manual]</u>. For information on bridges in the 2D domain see <u>[[TUFLOW_2D_Hydraulic_Structures \| 2D Hydraulic Structures]]</u> and <u>[[Tutorial_M11#Part_2_-_1D_Open_Channel_with_1D_Bridges_and_Weir_inflow_.282D.29_and_Outflow_.281D.29 \| Module 11]]</u>. <br>

ElizaCollison: /* Check Files */

2023-01-03T01:49:41Z

Check Files

← Older revision		Revision as of 11:49, 3 January 2023
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	=Check Files=		=Check Files=
	The table below highlights some of the commonly used check files when reviewing 1D bridges. The full list of TUFLOW check files can be found [[TUFLOW_Check_Files \| here]].		The table below highlights some of the commonly used check files when reviewing 1D bridges. The full list of TUFLOW check files can be found <u>[[TUFLOW_Check_Files \| here]]</u>.
	{\| align="left" class="wikitable" width="20%"		{\| align="left" class="wikitable" width="20%"

ElizaCollison: /* Irregular shaped bridges */

2023-01-03T01:49:17Z

Irregular shaped bridges

← Older revision		Revision as of 11:49, 3 January 2023
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	<br>		<br>

	=Irregular ~~shaped~~ ~~bridges~~=		=Irregular Shaped Bridges=
	~~In the UK arch shaped bridges can often be seen on waterways, whereas in Australia these types of structures are quite uncommon.~~ Modelling an irregular shaped bridge utilises the hydraulic properties elevation-width (CS/HW) type cross section and an irregular type culvert. <br>		Modelling an irregular shaped bridge utilises the hydraulic properties elevation-width (CS/HW) type cross section and an irregular type culvert. <br>

		⚫	[[File:Irregular_culvert_1.jpg\|border\|300px]]
	;Methodology
		⚫	[[File:Irregular_culvert_2.jpg\|border\|400px]]
	<ul>		<br>
⚫	1. Create a 1d_tab HW (height vs width) .csv file for each standard shape (ie. set up a database of the irregular shapes). For the height value you can start at a value of zero so that height becomes depth (this might making the .csv files easier). As the height increases the width changes to reflect the particular irregular shape you are modeling. In the example below, the width at the top of the arch (2.1m) is set to a small value of 0.001m as opposed to zero as the HW becomes NA past the top of the irregular shape. <br>
		⚫	London, UK (pht: Rohan King)<br>

			To create an irregular shaped bridge:
		⚫	<ol>
		⚫	<li>Create a 1d_tab HW (height vs width) .csv file for each standard shape (ie. set up a database of the irregular shapes). For the height value you can start at a value of zero so that height becomes depth (this might making the .csv files easier). As the height increases the width changes to reflect the particular irregular shape you are modeling. In the example below, the width at the top of the arch (2.1m) is set to a small value of 0.001m as opposed to zero as the HW becomes NA past the top of the irregular shape. <br>

	[[File:HW_arch_example.JPG\|border\|900px]] <br>		[[File:HW_arch_example.JPG\|border\|900px]] <br>
	<br>		<br>
	GIS example set up:<br>		GIS example set up:<br>
	[[File:Irregular_culvert_attribute_details.JPG\|border\|500px]]		[[File:Irregular_culvert_attribute_details.JPG\|border\|500px]]<br>
	<br>		<br>
		⚫	<li>Any number of 1d_tab lines can reference the same .csv file, ie. you don't need to have a unique .csv file for every 1d_tab line. <br>

⚫	2. Any number of 1d_tab lines can reference the same .csv file, ie. you don't need to have a unique .csv file for every 1d_tab line. <br>

	[[File:Arch HW attributes.JPG\|border\|300px]] <br>		[[File:Arch HW attributes.JPG\|border\|300px]] <br>

⚫	3. One option is to copy and paste the 1d_tab lines across each pipe (if you use a two vertex 1d_tab line there is no requirement that the 1d_tab line is snapped to the 1d_nwk pipe line - they just need to intersect). Each line will need to reference the relevant standard irregular shape HW .csv file (this could be automated using SQL Select if you have an attribute on the pipe to indicate which irregular shape it is). <br>
⚫	4. The inverts of the pipes should raise or lower the standard irregular shape cross-section to the appropriate height.
⚫	</ul>
	<br>		<br>
		⚫	<li>One option is to copy and paste the 1d_tab lines across each pipe (if you use a two vertex 1d_tab line there is no requirement that the 1d_tab line is snapped to the 1d_nwk pipe line - they just need to intersect). Each line will need to reference the relevant standard irregular shape HW .csv file (this could be automated using SQL Select if you have an attribute on the pipe to indicate which irregular shape it is). <br>
	;Real world examples
		⚫	<li>The inverts of the pipes should raise or lower the standard irregular shape cross-section to the appropriate height.
⚫	[[File:Irregular_culvert_1.jpg\|border\|300px]]
		⚫	</ol>
⚫	[[File:Irregular_culvert_2.jpg\|border\|400px]]
⚫	<br>
⚫	London, UK (pht: Rohan King)<br>
	<br>		<br>

	=Check Files=		=Check Files=
	The table below highlights some of the commonly used check files when reviewing 1D bridges. The full list of TUFLOW check files can be found [[TUFLOW_Check_Files \| here]].		The table below highlights some of the commonly used check files when reviewing 1D bridges. The full list of TUFLOW check files can be found [[TUFLOW_Check_Files \| here]].