751.2 Loads - Revision history

Hoskir: updated per RR3868

2024-07-19T18:35:05Z

updated per RR3868

← Older revision		Revision as of 13:35, 19 July 2024
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			<div style="float: right; margin-left: 30px; margin-bottom: 30px;">__TOC__</div>
	== 751.2.1 Permanent Loads ==		== 751.2.1 Permanent Loads ==


	=== 751.2.1.1 Dead Load ===		=== 751.2.1.1 Dead Load ===
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	'''Earthquake, <math>\, EQ</math>'''		'''Earthquake, <math>\, EQ</math>'''

	See [[751.~~9 LFD Seismic~~\|EPG 751.9 ~~LFD~~ Seismic]] ~~for~~ seismic design concepts and guidance for earthquake loads and modify as necessary for LRFD seismic~~. See[[:Category:756 Seismic Design\|EPG 756 Seismic Design]].~~		See [[751.9_Bridge_Seismic_Design\|EPG 751.9 Bridge Seismic Design]]. For seismic design concepts and guidance for earthquake loads follow LFD seismic process and modify as necessary for SGS/LRFD seismic.

	~~All new bridge/wall designs including nonseismic (or static) designs shall be required to meet Seismic Design Category A in accordance with AASHTO Guide Specifications for LRFD Seismic Bridge Design~~.

			All nonseismic (or static) and seismic new or replacement bridge designs must meet the Seismic Design Category (SDC) A requirements in accordance with SGS (Seismic Zone 1 of LRFD) for LRFD requirements. Additionally, provide seismic details only or perform seismic design of the abutments for SDC B, C and D region bridges or perform complete seismic analysis for SDC C and D region bridges in accordance with [https://epg.modot.org/forms/general_files/BR/Bridge_Seismic_Design_Flowchart.pdf Bridge Seismic Design Flowchart].

	~~<div id="Vehicular Collision Force, CT"></div>~~
	'''Vehicular Collision Force, CT'''		'''Vehicular Collision Force, CT'''

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	=== 751.2.4.2 Live Load Deflection ===		=== 751.2.4.2 Live Load Deflection ===

	The following recommendations are for new LRFD bridges. ~~Bridges currently~~ designed by the LFD method should be discussed with the Structural Project Manager or Liaison Engineer as to the appropriate approach. Widenings and rehabs will be handled on a case-by-case basis.		The following recommendations are for new LRFD bridges. Existing bridges designed by the LFD method should be discussed with the Structural Project Manager or Liaison Engineer as to the appropriate approach. Widenings and rehabs will be handled on a case-by-case basis.

	Live Load Deflection criteria shall be according to AASHTO LRFD 2.5.2.6.2..		Live Load Deflection criteria shall be according to AASHTO LRFD 2.5.2.6.2..

Hoskir: /* 751.2.2.3 Wind Loads */ fixed missing text

2023-08-14T19:14:00Z

751.2.2.3 Wind Loads: fixed missing text

← Older revision		Revision as of 14:14, 14 August 2023
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	Where:		Where:
	{\| style="margin-left: 30px;"		{\| style="margin-left: 30px;"
	\| style="text-align:right;" \| <math>P_Z = </math> \|\| style="text-align:left;" \| design wind pressure (ksf) (See table below for		\| style="text-align:right;" \| <math>P_Z = </math> \|\| style="text-align:left;" \| design wind pressure (ksf) (See table below for design wind pressures of typical bridges)
	\|-		\|-
	\|style="text-align:right;" \| <math>V = </math> \|\| style="text-align:left;" \| design 3-second gust wind speed (mph)		\|style="text-align:right;" \| <math>V = </math> \|\| style="text-align:left;" \| design 3-second gust wind speed (mph)

Hoskir: /* 751.2.2.3 Wind Loads */ fixed math formula

2023-08-14T18:02:39Z

751.2.2.3 Wind Loads: fixed math formula

← Older revision		Revision as of 13:02, 14 August 2023
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	For a value at a specific height:		For a value at a specific height:

	:<math>K_Z(B) = \frac {[2.5\ In\ ( \frac{Z}{0.9834} ) + 6.87]^2}{345.6} </math></br>		:<math>K_Z(B) = \frac {[2.5\ Ln\ ( \frac{Z}{0.9834} ) + 6.87]^2}{345.6} </math></br>
	:<math>K_Z(C) = \frac {[2.5\ In\ ( \frac{Z}{0.0984} ) + 7.35]^2}{478.4} </math></br>		:<math>K_Z(C) = \frac {[2.5\ Ln\ ( \frac{Z}{0.0984} ) + 7.35]^2}{478.4} </math></br>
	:<math>K_Z(D) = \frac {[2.5\ In\ ( \frac{Z}{0.0164} ) + 7.65]^2}{616.1} </math></br>		:<math>K_Z(D) = \frac {[2.5\ Ln\ ( \frac{Z}{0.0164} ) + 7.65]^2}{616.1} </math></br>
	Where <math>K_Z(B),\ K_Z(C),\ K_Z(D)\ are\ K_Z</math> for wind exposure Categories B, C, and D, respectively.</br>		Where <math>K_Z(B),\ K_Z(C),\ K_Z(D)\ are\ K_Z</math> for wind exposure Categories B, C, and D, respectively.</br>
	Note: In no case will the structure height, Z, used in calculating <math>K_Z</math> be taken less than 33.0 ft.		Note: In no case will the structure height, Z, used in calculating <math>K_Z</math> be taken less than 33.0 ft.

Hoskir: /* 751.2.2.3 Wind Load */ updated per RR3747

2023-08-14T17:19:38Z

751.2.2.3 Wind Load: updated per RR3747

Show changes

Smithk: /* 751.2.2.2 Water Load */ Per BR, minor clarification

2021-06-28T19:50:09Z

751.2.2.2 Water Load: Per BR, minor clarification

← Older revision		Revision as of 14:50, 28 June 2021
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	=== 751.2.2.2 Water Load ===		=== 751.2.2.2 Water Load ===

	'''Water Load, <math>\, WA</math> (~~Major river crossings~~ only)'''		'''Water Load, <math>\, WA</math> (Missouri River or Mississippi River only)'''

	The LRFD load designation for water load and stream pressure is <math>\, WA</math>.		The LRFD load designation for water load and stream pressure is <math>\, WA</math>.

Smithk: /* 751.2.2.6 Other Loads */ Per BR, updated pier protectin guidance to reflect latest AASHTO collision requirements with MoDOT policy exceptions.

2021-03-15T18:02:48Z

751.2.2.6 Other Loads: Per BR, updated pier protectin guidance to reflect latest AASHTO collision requirements with MoDOT policy exceptions.

← Older revision		Revision as of 13:02, 15 March 2021
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	'''Vehicular Collision Force, CT'''		'''Vehicular Collision Force, CT'''

	Abutments and piers located within ~~a distance of 30 feet to~~ the ~~edge of roadway or within a distance of 50 feet to the centerline of a railway track~~, shall be designed for an equivalent static force of ~~400~~ kip, which is assumed to act in ~~any~~ direction in a horizontal plane, at a distance ~~of 4~~ feet above ground.		Abutments and piers located within the clear zone, shall be designed for an equivalent static force of 600 kip, which is assumed to act in a direction parallel to or 15 degree skewed from the direction of traffic, in a horizontal plane, and at a distance between 2 and 5 feet above ground. The collision load shall be applied as a point load for columns, and as a distributed load, no greater than 5 feet wide by 2 feet tall, for walls. For design speeds not greater than 45 mph the design vehicular collision force may be reduced to 400 kip.

	Design for vehicular collision force ~~of 400 kip~~ is not required if abutment or pier is protected by:		Design for vehicular collision force is not required if abutment or pier is protected by:

	* An embankment		* An embankment.
	* A ~~54 inch TL5~~ barrier located ~~within 10 feet~~ from the pier or abutment.		* A Type D barrier located at least 2’-7” clear from the pier or abutment<sup>1</sup>.
	* A 42 inch TL5 barrier located ~~more than 10 feet~~ from the pier or abutment		* A minimum 42-inch MASH TL5 barrier where the top edge of front face is located at least 3’-3” from the pier or abutment<sup>1</sup>.
	* A collision wall meeting the standards provided in ~~these guidelines~~.		* A collision wall meeting the standards provided in [[751.31 Open Concrete Intermediate Bents#751.31.1.7 Collision Walls\|EPG 751.31.1.7 Collision Walls]].
	* A ~~guardrail~~ or barrier ~~that is consistent~~ with ~~the department’s roadway standards~~.		* MGS guardrail and Type C barrier in accordance with [https://www.modot.org/media/16865 Standard Plans 606.51] and [https://www.modot.org/media/16893 617.10].
			* Guardrail and Type A or B barrier for roadways with design speeds not greater than 45 mph and in accordance with [https://www.modot.org/media/16857 Standard Plans 606.01] and [https://www.modot.org/media/16893 617.10].

	~~Note~~: ~~TL5 refers~~ to a ~~“Test Level Five” crash test~~.		:'''<sup>1</sup>''' For barriers to adequately protect a pier from impact, a minimum barrier length of 60 feet upstream of the leading edge of the pier system plus the entire length of the pier system should be provided. If 60 feet is not available ask the SPM or SLE whether collision design is warranted.

	== 751.2.3 Load Factors and Combinations ==		== 751.2.3 Load Factors and Combinations ==

Smithk: /* 751.2.2.1 Live Load */

2020-08-05T13:57:19Z

751.2.2.1 Live Load

← Older revision		Revision as of 08:57, 5 August 2020
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	<div id="751.2.2.1 Live Load ~~2020~~.jpg"></div>		<div id="751.2.2.1 Live Load.jpg"></div>
	<center>[[Image:751.2.2.1 Live Load.jpg\|750px]]</center>		<center>[[Image:751.2.2.1 Live Load 2020.jpg\|750px]]</center>
	{\| style="margin: 1em auto 1em auto"		{\| style="margin: 1em auto 1em auto"
	\|-		\|-
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	For designing the deck overhang, the center of a truck wheel shall not be closer than one foot from the interior edge of barrier or railing.		For designing the deck overhang, the center of a truck wheel shall not be closer than one foot from the interior edge of barrier or railing.

	For all other applications, the center of a truck wheel shall not be closer than 2 feet from the interior edge of barrier or railing.		For all other applications, the center of a truck wheel shall not be closer than 2 feet from the interior edge of barrier or railing.

	=== 751.2.2.2 Water Load ===		=== 751.2.2.2 Water Load ===

Smithk: Per BR, numerous minor clarifications related to barrier pay items

2020-08-05T13:54:00Z

Per BR, numerous minor clarifications related to barrier pay items

← Older revision		Revision as of 08:54, 5 August 2020
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	<div id="751.2.2.1 Live Load.jpg"></div>		<div id="751.2.2.1 Live Load 2020.jpg"></div>
	<center>[[Image:751.2.2.1 Live Load.jpg\|750px]]</center>		<center>[[Image:751.2.2.1 Live Load.jpg\|750px]]</center>
	{\| style="margin: 1em auto 1em auto"		{\| style="margin: 1em auto 1em auto"
	\|-		\|-
	\|(*) 2'-0" Min.		\|'''*''' 2'-0" Min.
	\|-		\|-
	\|(**) 12" For deck overhang design (LRFD 3.6.1.3.1), 2’-0" for design of all other components		\|'''**''' 12" For deck overhang design (LRFD 3.6.1.3.1), 2’-0" for design of all other components
	\|}		\|}
	<center>'''Figure 2 General Application of Live Loads to Bridge Deck'''</center>		<center>'''Figure 2 General Application of Live Loads to Bridge Deck'''</center>
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	Axles that do not contribute to the maximum force effect shall not be included.		Axles that do not contribute to the maximum force effect shall not be included.

	For designing the deck overhang, the center of a truck wheel shall not be closer than ~~1 ft.~~ from the ~~face~~ of barrier ~~curb~~.		For designing the deck overhang, the center of a truck wheel shall not be closer than one foot from the interior edge of barrier or railing.

	For all other applications, the center of a truck wheel shall not be closer than 2 ~~ft.~~ from the ~~face~~ of barrier ~~curb~~.		For all other applications, the center of a truck wheel shall not be closer than 2 feet from the interior edge of barrier or railing.

	=== 751.2.2.2 Water Load ===		=== 751.2.2.2 Water Load ===
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	\|<math>\, L</math>\|\| = the overall bridge length, ft.		\|<math>\, L</math>\|\| = the overall bridge length, ft.
	\|-		\|-
	\|<math>\, H</math>\|\| = the total height of the girders, slab, barrier ~~curb~~ and any superelevation of the roadway, ~~ft.~~		\|<math>\, H</math>\|\| = the total height of the girders, slab, barrier or railing and any superelevation of the roadway, feet
	\|-		\|-
	\|<math>\, W</math>\|\| = wind force per unit area, psf		\|<math>\, W</math>\|\| = wind force per unit area, psf
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	Where:		Where:
	{\|		{\|
	\|valign="top"\|<math>\, d_e</math>\|\|= horizontal distance from the centerline of the exterior web of the exterior beam at deck level to the interior edge of ~~curb or traffic~~ barrier, ~~ft.~~		\|valign="top"\|<math>\, d_e</math>\|\|= horizontal distance from the centerline of the exterior web of the exterior beam at deck level to the interior edge of barrier of railing, feet
	\|}		\|}

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	Where:		Where:
	{\|		{\|
	\|valign="top"\|<math>\, d_e</math>\|\|= horizontal distance from the centerline of the exterior web of the exterior beam at deck level to the interior edge of ~~curb~~ or ~~traffic barrier~~, ~~ft.~~		\|valign="top"\|<math>\, d_e</math>\|\|= horizontal distance from the centerline of the exterior web of the exterior beam at deck level to the interior edge of barrier or railing, feet
	\|}		\|}

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	Non-composite dead loads (slab, girder) shall be distributed longitudinally to girders assuming simple supports and transversely to girders according to tributary widths.		Non-composite dead loads (slab, girder) shall be distributed longitudinally to girders assuming simple supports and transversely to girders according to tributary widths.

	Composite dead loads (future wearing surface, ~~safety~~ barrier ~~curb~~) shall be distributed equally to all girders.		Composite dead loads (future wearing surface, barrier or railing) shall be distributed equally to all girders.

Smithk: /* 751.2.1.1 Dead Load */

2020-02-04T20:44:37Z

751.2.1.1 Dead Load

← Older revision		Revision as of 15:44, 4 February 2020
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	=== 751.2.1.1 Dead Load ===		=== 751.2.1.1 Dead Load ===

	Included in dead loads are the weights of all structural components, appurtenances and utilities attached, wearing surfaces, earth cover~~, future overlays~~, and planned widenings. The following are the LRFD code designations:		Included in dead loads are the weights of all structural components, appurtenances and utilities attached, existing and future wearing surfaces, earth cover, and planned widenings. The following are the LRFD code designations:

	* ''DC'' – dead load of structural components and nonstructural attachments		* ''DC'' – dead load of structural components and nonstructural attachments

EPGsysop: /* 751.2.2.6 Other Loads */ Per BR, minor clarification

2018-04-03T16:18:02Z

751.2.2.6 Other Loads: Per BR, minor clarification

← Older revision		Revision as of 11:18, 3 April 2018
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	'''Earthquake, <math>\, EQ</math>'''		'''Earthquake, <math>\, EQ</math>'''

	See [[751.9 LFD Seismic\|EPG 751.9 LFD Seismic]] for seismic design for earthquake loads and [[:Category:756 Seismic Design\|EPG 756 Seismic Design]].		See [[751.9 LFD Seismic\|EPG 751.9 LFD Seismic]] for seismic design concepts and guidance for earthquake loads and modify as necessary for LRFD seismic. See[[:Category:756 Seismic Design\|EPG 756 Seismic Design]].

	All new bridge/wall designs including nonseismic (or static) designs shall be required to meet Seismic Design Category A in accordance with AASHTO Guide Specifications for LRFD Seismic Bridge Design.		All new bridge/wall designs including nonseismic (or static) designs shall be required to meet Seismic Design Category A in accordance with AASHTO Guide Specifications for LRFD Seismic Bridge Design.