Difference between revisions of "750.7 Non-Hydraulic Considerations"

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m (→‎750.7.2.7 Multiple Opening Installations: Per BR, removed duplicate info from EPG 750.7.2.7 (is already presented in EPG 750.7.4.3)
 
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{| border="1" class="wikitable" style="margin: 1em auto 1em auto"
 
{| border="1" class="wikitable" style="margin: 1em auto 1em auto"
 
|+ '''Permissible Pipe Types by Group'''
 
|+ '''Permissible Pipe Types by Group'''
! style="background:#BEBEBE"|Group A (ADT>3500) !! style="background:#BEBEBE"| Group B (ADT&le;3500) !! style="background:#BEBEBE"|Group C (ADT<1700)
+
! style="background:#BEBEBE"|Group A (ADT>3500) !! style="background:#BEBEBE"| Group B (ADT&le;3500) !! style="background:#BEBEBE"|Group C (Other Applications)  
 
|-
 
|-
 
| Reinforced Concrete || Group A Pipe || Group A Pipe
 
| Reinforced Concrete || Group A Pipe || Group A Pipe
 
|-
 
|-
| Vitrified Clay || Polypropylene || Group B Pipe
+
| Vitrified Clay || ||Group B Pipe  
 
|-
 
|-
| Aluminum Coated Steel || High Density Polyethylene || Zinc-Coated Steel
+
|Aluminum Coated Steel|| High Density Polyethylene ≤60 in. ||Zinc-Coated Steel  
 
|-
 
|-
| Polymer Coated Steel|| Steel Reinforced Polyethylene || Bituminous-Coated Steel
+
|Polymer Coated Steel|| Steel Reinforced Polyethylene ≤60 in. ||Bituminous-Coated Steel  
 
|-
 
|-
| Aluminum Alloy || Polyvinyl chloride || rowspan="5" |
+
|Aluminum Alloy ||rowspan="6" colspan="2"|
 
|-
 
|-
| Polypropylene &le;36 in. || rowspan="4" |
+
|Triple Wall Polypropylene ≤60 in.  
 
|-
 
|-
| High Density Polyethylene &le;24 in.
+
|Double Wall Polypropylene ≤30 in
 
|-
 
|-
| Steel Reinforced Polyethylene &le;24 in.
+
|High Density Polyethylene ≤24 in.
 
|-
 
|-
| Polyvinyl chloride &le;36 in.
+
|Steel Reinforced Polyethylene ≤24 in.
 +
|-
 +
|Polyvinyl chloride ≤36 in.
 
|}
 
|}
  
In general, a group of permissible culvert types, dependent upon the design ADT, is specified as described in succeeding sections. For special situations, a qualified pipe group may be specified, as described in [[#750.7.2.5 Installations for Special Situations|Installations for Special Situations]]. The final selection of the structure type is based on requirements in the standard specifications, on good engineering judgment, and economy with consideration of service and maintenance costs.
+
In general, there are two methods of specifying the permissible culvert types dependent upon the design ADT. For most applications, a group of culvert types is specified as described in succeeding sections. For special situations, a qualified pipe group may be specified, as described in [[#750.7.2.5 Installations for Special Situations|Installations for Special Situations]]. The final selection of the structure type is based on requirements in the standard specifications, on good engineering judgment, and economy with consideration of service and maintenance costs.
  
 
===750.7.2.1 Roadways with ADT > 3500===
 
===750.7.2.1 Roadways with ADT > 3500===
For roadways with ADT > 3500, Group A pipe will be specified for crossroad structures. The hydraulic design computations for Group A pipe should be performed for both corrugated and smooth wall pipe. At each pipe location on the plans, both the corrugated and equivalent smooth wall diameters should be shown, as in the following example.
+
For roadways with ADT > 3500, reinforced concrete pipe will be specified for crossroad structures, except for the following conditions:
 
 
:::36" Group A Pipe (30")
 
:::36" Group A Pipe (36")
 
 
 
The first number shown represents the corrugated diameter and is the value used for the pay item, while the number shown in parenthesis is the equivalent smooth wall pipe diameter. The latter must be shown whether the size is equal to or less than the corrugated size.
 
 
 
The following exceptions apply to the use of Group A pipe:
 
  
 
*Reinforced concrete box culverts are specified when it is more economical to build the reinforced box culvert than it is to provide an equivalent pipe culvert.
 
*Reinforced concrete box culverts are specified when it is more economical to build the reinforced box culvert than it is to provide an equivalent pipe culvert.
 
*Vitrified clay pipe (extra strength) is specified when the purpose of the culvert is a sanitary sewer.
 
*Vitrified clay pipe (extra strength) is specified when the purpose of the culvert is a sanitary sewer.
*Group C pipe should be specified for the portion of median outlet pipes outside the edge of pavement where such pipes are located on high fills requiring a break in flowline grade.  Details for such installations are illustrated in [[Media:750.7 Pipe Grades For Median Drop Inlets.pdf|Pipe Grades For Median Drop Inlets]].
+
*Group B pipe should be specified for the portion of median outlet pipes outside the edge of pavement where such pipes are located on high fills requiring a break in flowline grade.  Details for such installations are illustrated in [[Media:750.7 Pipe Grades For Median Drop Inlets.pdf|Pipe Grades For Median Drop Inlets]].
 
*Group B pipe is specified to drain drop inlets into crossroad drainage structures when such installation necessitates a steep flowline grade and when the pipe will not extend under the pavement or in other non-traffic areas, such as behind guardrail at median piers.
 
*Group B pipe is specified to drain drop inlets into crossroad drainage structures when such installation necessitates a steep flowline grade and when the pipe will not extend under the pavement or in other non-traffic areas, such as behind guardrail at median piers.
  
Line 69: Line 64:
  
 
===750.7.2.2 Roadways with ADT &le; 3500===
 
===750.7.2.2 Roadways with ADT &le; 3500===
For roadways with ADT &le; 3500, Group B pipe should be specified according to the method used for Group A.
+
For roadways with ADT &le; 3500, Group B pipe should be specified for crossroad structures. The hydraulic design computations for Group B pipe should be performed for both corrugated and smooth wall pipe. The pay item for the corrugated pipe size should be used. At each pipe location on the plans, both the corrugated and equivalent smooth wall diameters should be shown as in the following examples:
+
 
Some exceptions to specifying Group B on the plans are the following:
+
:::36" Group B Pipe (30")
 +
:::36" Group B Pipe (36")
 +
 
 +
The equivalent smooth wall diameter must be shown whether the size is equal to or less than the corrugated size. The standard specifications for pipe and end sections describe the nomenclature for this procedure. Some exceptions to specifying Group B on the plans are the following:
  
 
*Reinforced concrete box culverts should be considered for pipes larger than 60 in. diameter.
 
*Reinforced concrete box culverts should be considered for pipes larger than 60 in. diameter.
Line 80: Line 78:
 
Pipes of 12 in. and 15 in. are not used for crossroad culverts, except where the use of an 18 in. pipe will create an unsightly or impracticable drainage condition.
 
Pipes of 12 in. and 15 in. are not used for crossroad culverts, except where the use of an 18 in. pipe will create an unsightly or impracticable drainage condition.
  
Corrugated polyethylene pipe (Type S) and polyvinyl chloride pipe are double walled, full circular cross section pipes, with an outer corrugated wall and a smooth inner liner. Only 12 to 60 in. diameter sizes of corrugated polyethylene, or 12 to 48 in. diameter sizes of PVC pipe, are approved for use on highway projects. Corrugations may be either annular or helical. Headwall protection is provided by means of a beveled pipe end treatment, safety slope end section, or metal or concrete flared end sections. [http://www.modot.org/business/standards_and_specs/SpecbookEPG.pdf#page=11 Section 730] of the Standard Specifications require all PVC pipes to have an end section of one of the other Group B pipe materials to protect from ultraviolet degradation where the end of the pipe is exposed.
+
Corrugated polyethylene pipe (Type S) and polyvinyl chloride pipe are double walled, full circular cross section pipes, with an outer corrugated wall and a smooth inner liner. Only 12 to 60 in. diameter sizes of corrugated polyethylene, or 12 to 48 in. diameter sizes of PVC pipe, are approved for use on highway projects. Corrugations may be either annular or helical. Headwall protection is provided by means of a beveled pipe end treatment, safety slope end section, or metal or concrete flared end sections. [http://modot.mo.gov/business/standards_and_specs/Sec0728.pdf Section 728] of the Standard Specifications require all PVC pipes to have an end section of one of the other Group B pipe materials to protect from ultraviolet degradation where the end of the pipe is exposed.
  
 
===750.7.2.3 Roadways and Roadside Applications with ADT < 1700===
 
===750.7.2.3 Roadways and Roadside Applications with ADT < 1700===
For roadways, side roads, and entrances with ADT < 1700 Group C pipe should be specified according to the methods used for Groups A and B. For information regarding replacement of failed driveway drainage pipes see [[:Category:941 Permits and Access Requests#941.9.8 Maintenance of Residential, Commercial, and Public Road Entrances|EPG 941.9.8 Maintenance of Residential, Commercial and Public Road Entrances]].
+
For roadways, side roads, and entrances with ADT < 1700 Group C pipe should be specified using the same method for corrugated and smooth wall Group B pipe as explained in [[#750.7.2.2 Roadways with ADT ≤ 3500|Roadways with ADT ≤ 3500]]. For information regarding replacement of failed driveway drainage pipes see [[:Category:941 Permits and Access Requests#941.9.8.4 Drainage Structures|EPG 941.9.8.4 Drainage Structures]].
  
 
===750.7.2.4 Other Roadway Drainage Structures===
 
===750.7.2.4 Other Roadway Drainage Structures===
Line 99: Line 97:
  
 
===750.7.2.7 Multiple Opening Installations===
 
===750.7.2.7 Multiple Opening Installations===
Multiple opening structures, either boxes or pipes, are used as required where the allowable structure height is restricted or to meet [[750.2 Culverts|hydraulic design]] or [[#750.7.3 Environmental Requirements|environmental requirements]]. Where multiple pipes are constructed, the pipes are separated by a distance of 1/2 their outside diameter, or a minimum of 1 ft., whichever is greater.  [[#750.7.4.3 Summary of Responsibilities|Analysis, design and final plans preparation responsibility]] for multiple cell box culverts is based on several factors including drainage area.  
+
Multiple opening structures, either boxes or pipes, are used only as required where the allowable structure height is restricted. Where multiple pipes are constructed, the pipes are separated by a distance of 1/2 their outside diameter, or a minimum of 1 ft., whichever is greater.
  
 
===750.7.2.8 Temporary Installations===
 
===750.7.2.8 Temporary Installations===
Line 106: Line 104:
 
==750.7.3 Environmental Requirements==
 
==750.7.3 Environmental Requirements==
 
   
 
   
[http://epg.modot.org/index.php?title=127.4_Wetlands_and_Streams#127.4.1.1__Overview Waters of the United States] are under the jurisdiction of the U.S. Army Corps of Engineers (COE) which has implemented a [http://www.nwk.usace.army.mil/Portals/29/docs/regulatory/nationwidepermits/2012/MORC1Streams.pdf Regional Condition] , affecting new and replacement culverts, to [[127.4 Wetlands and Streams|Section 404 Nationwide Permits]] ( all Nationwide Permits including NWP 14, Linear Transportation Projects and NWP 3, Maintenance Activities) for Missouri.
+
[http://epg.modot.org/index.php?title=127.4_Wetlands_and_Streams#127.4.1.1__Overview Waters of the United States] are under the jurisdiction of the U.S. Army Corps of Engineers (COE) which has implemented a [http://usace.contentdm.oclc.org/utils/getfile/collection/p16021coll11/id/2654 Regional Condition], affecting new and replacement culverts, to [[127.4 Wetlands and Streams|Section 404 Nationwide Permits]] (all Nationwide Permits including NWP 14, Linear Transportation Projects and NWP 3, Maintenance Activities) for Missouri.  
 
 
A list of perennial and intermittent streams is available in [[127.4 Wetlands and Streams#127.4.1.1 Overview|EPG 127.4.1.1 Overview]].
 
  
 +
If meeting the requirements of the Regional Condition is not feasible, or requires unreasonable measures or expense, a waiver can be requested from the COE. For more information, or to request a waiver, contact a Wetlands Specialist in the [http://sp/sites/de/environmental_historic_pres/SitePages/Home.aspx Environmental Section] of the Design Division.
  
 
<center>  
 
<center>  
Line 134: Line 131:
 
</center>
 
</center>
  
 +
===750.7.3.1 Stream Classifications===
 +
A list, of perennial and intermittent streams, is available in [[127.4 Wetlands and Streams#127.4.1.1 Overview|EPG 127.4.1.1 Overview]]. This list does not include all perennial and intermittent streams in the state.  Streams not listed in this list or thought to be a different class than what is represented, should be further evaluated to determine their classification. The Wetlands Specialist in the Environmental Section of the Design Division will likely have visited the site and have, photos and/or, notes on the stream classification. The following sources are examples of information that may be used to aid in determination of the stream classification:
 +
 +
:* Survey Field Notes from Wetland Specialist and/or Survey Crew
 +
:* Bridge Survey Report
 +
:* USGS Topographical Maps
 +
:* Photos
 +
:* Aerial or Satellite Imagery
 +
 +
===750.7.3.2 Embedment Requirements===
 +
The regional condition encourages the use of single culverts. If multiple culverts are used, all must be embedded to the same invert elevation.
  
===750.7.3.1 Embedment Requirements===
+
:'''Perennial and Intermittent Streams'''
The regional condition encourages the use of single culverts. If multiple culverts are used, all must be embedded to the same invert elevation.
+
::<u>Total width of all culverts within the stream channel > 4’ (diameter for circular culverts):</u>
 +
:::* Culvert Extensions and Repairs – No Embedment Required
 +
:::* New and Replacement Culverts
 +
:::::* 1’ minimum embedment of culvert invert below natural stream bottom, except that:
 +
:::::* Invert may be placed flush with stream bottom in non-erodible channels.
 +
:::::* Invert should be embedded deeper in streams with highly erodible beds.
 +
::<u>Total width of all culverts within the stream channel < 4’ (diameter for circular culverts):</u>
 +
:::* Invert placed flush with stream bottom, except that:
 +
:::* Invert should be embedded in streams with highly erodible beds.
 +
 
 +
:'''Ephemeral Streams'''
  
Perennial and Intermittent Streams
 
:* Total width of all culverts within the stream channel > 4’ (diameter for circular culverts).
 
 
::* Culvert Extensions and Repairs – No Embedment Required
 
::* Culvert Extensions and Repairs – No Embedment Required
 
::* New and Replacement Culverts
 
::* New and Replacement Culverts
::::* 1’ minimum embedment of culvert invert below natural stream bottom, except that:
+
:::* Invert placed flush with stream bottom, except that:
::::* Invert may be placed flush with stream bottom in non-erodible channels.
+
:::* Invert should be embedded in streams with highly erodible beds.
::::* Invert should be embedded deeper in streams with highly erodible beds.
 
:* Total width of all culverts within the stream channel < 4’ (diameter for circular culverts).
 
::* Invert placed flush with stream bottom, except that:
 
::* Invert should be embedded in streams with highly erodible beds.
 
 
 
Ephemeral Streams
 
 
 
:* Culvert Extensions and Repairs – No Embedment Required
 
:* New and Replacement Culverts
 
::* Invert placed flush with stream bottom, except that:
 
::* Invert should be embedded in streams with highly erodible beds.
 
  
 
The embedded area shall be allowed to naturally backfill and shall not be included as part of the flow area for hydraulic design calculations.  
 
The embedded area shall be allowed to naturally backfill and shall not be included as part of the flow area for hydraulic design calculations.  
Line 160: Line 165:
 
On streams with highly erodible beds, grade control measures may be applied as necessary to prevent erosion and maintain aquatic life movement.
 
On streams with highly erodible beds, grade control measures may be applied as necessary to prevent erosion and maintain aquatic life movement.
  
===750.7.3.2 Hydraulic Requirements===
+
===750.7.3.3 Hydraulic Requirements===
 
In addition to the embedment requirements, new and replacement culverts with a width (diameter for circular culverts) greater than 4 ft. (total width of all culverts within the stream channel), on perennial and intermittent streams are required to convey a portion of the bankfull flow area.  
 
In addition to the embedment requirements, new and replacement culverts with a width (diameter for circular culverts) greater than 4 ft. (total width of all culverts within the stream channel), on perennial and intermittent streams are required to convey a portion of the bankfull flow area.  
  
Bankfull flow area is the area within the stream channel between the bankfull stage and the bottom of the channel. Bankfull stage is defined as the lowest bank elevation where water begins to overflow on the floodplain. On highly incised streams, where the bankfull stage is higher than a 100-yr flood event, contact a Wetlands Specialist in the Environmental section for consultation with the Corps to determine the appropriate bankfull stage.  
+
Bankfull flow area is the area within the stream channel between the bankfull stage and the bottom of the channel. Bankfull stage is defined as the lowest bank elevation where water begins to overflow on the floodplain. On highly incised streams, where the bankfull stage is higher than a 100-yr. flood event, contact a Wetlands Specialist in the Environmental section for consultation with the Corps to determine the appropriate bankfull stage.  
  
 
Once the bankfull stage and associated area have been determined the minimum area of the culvert can be determined. The Regional Condition provides guidance for the following [[127.4 Wetlands and Streams#127.4.1.1 Overview|regulated stream types]]:  
 
Once the bankfull stage and associated area have been determined the minimum area of the culvert can be determined. The Regional Condition provides guidance for the following [[127.4 Wetlands and Streams#127.4.1.1 Overview|regulated stream types]]:  
Line 188: Line 193:
 
! colspan="2" style="background:#BEBEBE"|General Details
 
! colspan="2" style="background:#BEBEBE"|General Details
 
|-
 
|-
|Wing J-bars & Wing Backfill Slopes ||width="100"|[http://www.modot.org/business/standards_and_specs/documents/70337.pdf 703.37]
+
|Wing J-bars & Wing Backfill Slopes ||width="100"|[http://www2.modot.org/business/standards_and_specs/documents/70337.pdf 703.37]
 
|-
 
|-
|Cutting Details for Partial Removal ||[http://www.modot.org/business/standards_and_specs/documents/70338.pdf 703.38]
+
|Cutting Details for Partial Removal ||[http://www2.modot.org/business/standards_and_specs/documents/70338.pdf 703.38]
 
|-
 
|-
|Pipe Inlets ||[http://www.modot.org/business/standards_and_specs/documents/70360.pdf 703.60]
+
|Pipe Inlets ||[http://www2.modot.org/business/standards_and_specs/documents/70360.pdf 703.60]
 
|-
 
|-
|Bar Supports for Concrete ||[http://www.modot.org/business/standards_and_specs/documents/70635.pdf 706.35]
+
|Bar Supports for Concrete ||[http://www2.modot.org/business/standards_and_specs/documents/70635.pdf 706.35]
 
|}
 
|}
  
Line 202: Line 207:
 
!  style="background:#BEBEBE"|Culvert Details||style="background:#BEBEBE"| Single Box||style="background:#BEBEBE"| Double Box|| style="background:#BEBEBE"| Triple  Box
 
!  style="background:#BEBEBE"|Culvert Details||style="background:#BEBEBE"| Single Box||style="background:#BEBEBE"| Double Box|| style="background:#BEBEBE"| Triple  Box
 
|-
 
|-
|Square - Straight Wings||[http://www.modot.org/business/standards_and_specs/documents/70310.pdf 703.10] || [http://www.modot.org/business/standards_and_specs/documents/70340.pdf 703.40] ||[http://www.modot.org/business/standards_and_specs/documents/70380.pdf 703.80]
+
|Square - Straight Wings||[http://www2.modot.org/business/standards_and_specs/documents/70310.pdf 703.10] || [http://www2.modot.org/business/standards_and_specs/documents/70340.pdf 703.40] ||[http://www2.modot.org/business/standards_and_specs/documents/70380.pdf 703.80]
 
|-
 
|-
|Square - Flared Wings ||[http://www.modot.org/business/standards_and_specs/documents/70311.pdf 703.11] ||[http://www.modot.org/business/standards_and_specs/documents/70341.pdf 703.41] ||[http://www.modot.org/business/standards_and_specs/documents/70381.pdf 703.81]  
+
|Square - Flared Wings ||[http://www2.modot.org/business/standards_and_specs/documents/70311.pdf 703.11] ||[http://www2.modot.org/business/standards_and_specs/documents/70341.pdf 703.41] ||[http://www2.modot.org/business/standards_and_specs/documents/70381.pdf 703.81]  
 
|-
 
|-
|Left Ahead - Straight Wings ||[http://www.modot.org/business/standards_and_specs/documents/70312.pdf 703.12] || [http://www.modot.org/business/standards_and_specs/documents/70342.pdf 703.42] ||[http://www.modot.org/business/standards_and_specs/documents/70382.pdf 703.82]
+
|Left Ahead - Straight Wings ||[http://www2.modot.org/business/standards_and_specs/documents/70312.pdf 703.12] || [http://www2.modot.org/business/standards_and_specs/documents/70342.pdf 703.42] ||[http://www2.modot.org/business/standards_and_specs/documents/70382.pdf 703.82]
 
|-
 
|-
|Left Ahead - Flared Wings ||[http://www.modot.org/business/standards_and_specs/documents/70313.pdf 703.13] ||[http://www.modot.org/business/standards_and_specs/documents/70343.pdf 703.43] ||[http://www.modot.org/business/standards_and_specs/documents/70383.pdf 703.83]
+
|Left Ahead - Flared Wings ||[http://www2.modot.org/business/standards_and_specs/documents/70313.pdf 703.13] ||[http://www2.modot.org/business/standards_and_specs/documents/70343.pdf 703.43] ||[http://www2.modot.org/business/standards_and_specs/documents/70383.pdf 703.83]
 
|-
 
|-
|Right Ahead - Straight Wings ||[http://www.modot.org/business/standards_and_specs/documents/70314.pdf 703.14] ||[http://www.modot.org/business/standards_and_specs/documents/70344.pdf 703.44] || [http://www.modot.org/business/standards_and_specs/documents/70384.pdf 703.84]  
+
|Right Ahead - Straight Wings ||[http://www2.modot.org/business/standards_and_specs/documents/70314.pdf 703.14] ||[http://www2.modot.org/business/standards_and_specs/documents/70344.pdf 703.44] || [http://www2.modot.org/business/standards_and_specs/documents/70384.pdf 703.84]  
 
|-
 
|-
|Right Ahead - Flared Wings ||[http://www.modot.org/business/standards_and_specs/documents/70315.pdf 703.15] ||[http://www.modot.org/business/standards_and_specs/documents/70345.pdf 703.45] ||[http://www.modot.org/business/standards_and_specs/documents/70385.pdf 703.85]
+
|Right Ahead - Flared Wings ||[http://www2.modot.org/business/standards_and_specs/documents/70315.pdf 703.15] ||[http://www2.modot.org/business/standards_and_specs/documents/70345.pdf 703.45] ||[http://www2.modot.org/business/standards_and_specs/documents/70385.pdf 703.85]
 
|-
 
|-
|Cut Sections ||[http://www.modot.org/business/standards_and_specs/documents/70316.pdf 703.16] ||[http://www.modot.org/business/standards_and_specs/documents/70346.pdf 703.46] ||[http://www.modot.org/business/standards_and_specs/documents/70386.pdf 703.86]
+
|Cut Sections ||[http://www2.modot.org/business/standards_and_specs/documents/70316.pdf 703.16] ||[http://www2.modot.org/business/standards_and_specs/documents/70346.pdf 703.46] ||[http://www2.modot.org/business/standards_and_specs/documents/70386.pdf 703.86]
 
|-
 
|-
|Member Size & Reinforcement Tables ||[http://www.modot.org/business/standards_and_specs/documents/70317.pdf 703.17] ||[http://www.modot.org/business/standards_and_specs/documents/70347.pdf 703.47] ||[http://www.modot.org/business/standards_and_specs/documents/70387.pdf 703.87]
+
|Member Size & Reinforcement Tables ||[http://www2.modot.org/business/standards_and_specs/documents/70317.pdf 703.17] ||[http://www2.modot.org/business/standards_and_specs/documents/70347.pdf 703.47] ||[http://www2.modot.org/business/standards_and_specs/documents/70387.pdf 703.87]
 
|}
 
|}
  
Line 264: Line 269:
  
 
</center>
 
</center>
 +
 
===750.7.4.2 Abrasion of Interior Surfaces===
 
===750.7.4.2 Abrasion of Interior Surfaces===
  
Line 394: Line 400:
 
==750.7.11 Overfill Heights==
 
==750.7.11 Overfill Heights==
 
===750.7.11.1 Minimum Fill Heights===
 
===750.7.11.1 Minimum Fill Heights===
The minimum allowable fill or cover for all structures is 1 ft. at the outside shoulder line, (refer to [[751.1 Preliminary Design#751.1.2.6.3.3 Roadway Fill|EPG 751.2.6.3.3 Box Culverts, Roadway Fill]] for details of warping fill over exposed portions of box culverts), with the following exceptions:
+
The minimum allowable fill or cover for all structures is 1 ft. at the outside shoulder line, (refer to [[751.1 Preliminary Design#751.1.2.8.3.3 Roadway Fill|EPG 751.1.2.8.3.3 Box Culverts, Roadway Fill]] for details of warping fill over exposed portions of box culverts), with the following exceptions:
  
 
*The minimum fill for structural-plate pipe structures is tabulated in [[Media:750.7 Overfill Structural Plate Pipe.pdf|Allowable Overfills for Structural Plate Pipe]].
 
*The minimum fill for structural-plate pipe structures is tabulated in [[Media:750.7 Overfill Structural Plate Pipe.pdf|Allowable Overfills for Structural Plate Pipe]].
Line 435: Line 441:
  
 
===750.7.13.1 Box Culverts===
 
===750.7.13.1 Box Culverts===
For additional information on culvert length, see [[751.1 Preliminary Design#751.1.2.6.3.2 Length|EPG 751.1.2.6.3.2 Length]]. For maximum length of box culver barrels and box culvert cut sections, refer to [[751.8 LRFD Concrete Box Culverts#751.8.3.1 Joints|EPG 751.8.3.1 Joints, Transverse Joints]] and [[751.8 LRFD Concrete Box Culverts#751.8.1.3 Barrel Section Dimensions|EPG 751.8.1.3 Barrel Section Dimensions]].  
+
For additional information on culvert length, see [[751.1 Preliminary Design#751.1.2.8.3.2 Length|EPG 751.1.2.8.3.2 Length]]. For maximum length of box culver barrels and box culvert cut sections, refer to [[751.8 LRFD Concrete Box Culverts#751.8.3.1 Joints|EPG 751.8.3.1 Joints, Transverse Joints]] and [[751.8 LRFD Concrete Box Culverts#751.8.1.3 Barrel Section Dimensions|EPG 751.8.1.3 Barrel Section Dimensions]].  
  
 
===750.7.13.2 Pipes===
 
===750.7.13.2 Pipes===

Latest revision as of 13:42, 28 April 2020

Metal and Concrete Pipe
Report 2008
High Density Polyethylene (HDPE) Pipe Culverts
Summary 2002
Report 2002
Summary 2002
Report 2002
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Contents

750.7.1 General

Drainage structures are located and designed to adequately handle runoff across improvements and to handle runoff from the improvement. Non-Hydraulic Considerations presents criteria pertaining to the selection of culvert and storm sewer material and appurtenances. The hydraulic design of culverts and other drainage facilities is discussed in other articles under Hydraulic Analysis.

750.7.2 Types

Permissible culvert pipe types are separated into the following groups.

Permissible Pipe Types by Group
Group A (ADT>3500) Group B (ADT≤3500) Group C (Other Applications)
Reinforced Concrete Group A Pipe Group A Pipe
Vitrified Clay Group B Pipe
Aluminum Coated Steel High Density Polyethylene ≤60 in. Zinc-Coated Steel
Polymer Coated Steel Steel Reinforced Polyethylene ≤60 in. Bituminous-Coated Steel
Aluminum Alloy
Triple Wall Polypropylene ≤60 in.
Double Wall Polypropylene ≤30 in
High Density Polyethylene ≤24 in.
Steel Reinforced Polyethylene ≤24 in.
Polyvinyl chloride ≤36 in.

In general, there are two methods of specifying the permissible culvert types dependent upon the design ADT. For most applications, a group of culvert types is specified as described in succeeding sections. For special situations, a qualified pipe group may be specified, as described in Installations for Special Situations. The final selection of the structure type is based on requirements in the standard specifications, on good engineering judgment, and economy with consideration of service and maintenance costs.

750.7.2.1 Roadways with ADT > 3500

For roadways with ADT > 3500, reinforced concrete pipe will be specified for crossroad structures, except for the following conditions:

  • Reinforced concrete box culverts are specified when it is more economical to build the reinforced box culvert than it is to provide an equivalent pipe culvert.
  • Vitrified clay pipe (extra strength) is specified when the purpose of the culvert is a sanitary sewer.
  • Group B pipe should be specified for the portion of median outlet pipes outside the edge of pavement where such pipes are located on high fills requiring a break in flowline grade. Details for such installations are illustrated in Pipe Grades For Median Drop Inlets.
  • Group B pipe is specified to drain drop inlets into crossroad drainage structures when such installation necessitates a steep flowline grade and when the pipe will not extend under the pavement or in other non-traffic areas, such as behind guardrail at median piers.

Pipes of 12 in. and 15 in. are not used except as outlets from drop inlets and in storm sewer systems.

The requirements for using reinforced concrete pipe or vitrified clay pipe for structures may be waived if conditions warrant, such as poor structure foundation conditions, high fills, simplification of handling traffic, etc.

750.7.2.2 Roadways with ADT ≤ 3500

For roadways with ADT ≤ 3500, Group B pipe should be specified for crossroad structures. The hydraulic design computations for Group B pipe should be performed for both corrugated and smooth wall pipe. The pay item for the corrugated pipe size should be used. At each pipe location on the plans, both the corrugated and equivalent smooth wall diameters should be shown as in the following examples:

36" Group B Pipe (30")
36" Group B Pipe (36")

The equivalent smooth wall diameter must be shown whether the size is equal to or less than the corrugated size. The standard specifications for pipe and end sections describe the nomenclature for this procedure. Some exceptions to specifying Group B on the plans are the following:

  • Reinforced concrete box culverts should be considered for pipes larger than 60 in. diameter.
  • Reinforced concrete pipe, corrugated polyethylene