Culvert

Last updated

Steel culvert with a plunge pool below Culvert Picture.jpg
Steel culvert with a plunge pool below
Steel corrugated culvert with a drop on the exhaust end, Northern Vermont Culvert with a drop.jpg
Steel corrugated culvert with a drop on the exhaust end, Northern Vermont
A multiple culvert assembly in Italy Feccia 001.JPG
A multiple culvert assembly in Italy
Concrete box culverts. Culvert on Fordingbridge to Alderholt Road - geograph.org.uk - 155781.jpg
Concrete box culverts.
A culvert under the Vistula river levee and a street in Warsaw. Kanal Nowa Ulga, Wal Miedzeszynski, Warszawa 004.jpg
A culvert under the Vistula river levee and a street in Warsaw.

A culvert is a structure that allows water to flow under a road, railroad, trail, or similar obstruction from one side to the other. Typically embedded so as to be surrounded by soil, a culvert may be made from a pipe, reinforced concrete or other material. In the United Kingdom, the word can also be used for a longer artificially buried watercourse. [1]

Contents

Culverts are commonly used both as cross-drains to relieve drainage of ditches at the roadside, and to pass water under a road at natural drainage and stream crossings. A culvert may be a bridge-like structure designed to allow vehicle or pedestrian traffic to cross over the waterway while allowing adequate passage for the water.

Culverts come in many sizes and shapes including round, elliptical, flat-bottomed, open-bottomed, pear-shaped, and box-like constructions. The culvert type and shape selection is based on a number of factors including requirements for hydraulic performance, limitations on upstream water surface elevation, and roadway embankment height. [2]

The process of removing culverts to restore an open-air watercourse is known as daylighting. In the UK, the practice is also known as deculverting. [3]

Materials

Culverts can be constructed of a variety of materials including cast-in-place or precast concrete (reinforced or non-reinforced), galvanized steel, aluminum, or plastic (typically high-density polyethylene). Two or more materials may be combined to form composite structures. For example, open-bottom corrugated steel structures are often built on concrete footings.

Design and engineering

Holbrook, a tributary of the River Tame, emerges from a brick-lined culvert, north Birmingham Holbrook at Beeches Road, Birmingham - 2017-11-10 - Andy Mabbett - 04.jpg
Holbrook, a tributary of the River Tame, emerges from a brick-lined culvert, north Birmingham

Construction or installation at a culvert site generally results in disturbance of the site's soil, stream banks, or stream bed, and can result in the occurrence of unwanted problems such as scour holes or slumping of banks adjacent to the culvert structure. [2] [4]

Culverts must be properly sized and installed, and protected from erosion and scour. Many U.S. agencies such as the Federal Highway Administration, Bureau of Land Management, [5] and Environmental Protection Agency, [6] as well as state or local authorities, [4] require that culverts be designed and engineered to meet specific federal, state, or local regulations and guidelines to ensure proper function and to protect against culvert failures.

Culverts are classified by standards for their load capacities, water flow capacities, life spans, and installation requirements for bedding and backfill. [2] Most agencies adhere to these standards when designing, engineering, and specifying culverts.

Failures

Culvert failures can occur for a wide variety of reasons including maintenance, environmental, and installation-related failures, functional or process failures related to capacity and volume causing the erosion of the soil around or under them, and structural or material failures that cause culverts to fail due to collapse or corrosion of the materials from which they are made. [7]

If the failure is sudden and catastrophic, it can result in injury or loss of life. Sudden road collapses are often the result of poorly designed and engineered culvert crossing sites or unexpected changes in the surrounding environment cause design parameters to be exceeded. Water passing through undersized culverts will scour away the surrounding soil over time. This can cause a sudden failure during medium-sized rain events. Accidents from culvert failure can also occur if a culvert has not been adequately sized and a flood event overwhelms the culvert, or disrupts the road or railway above it.

Ongoing culvert function without failure depends on proper design and engineering considerations being given to load, hydraulic flow, surrounding soil analysis, backfill and bedding compaction, and erosion protection. Improperly designed backfill support around culverts can result in material collapse or failure from inadequate load support. [7] [2]

For existing culverts which have experienced degradation, loss of structural integrity or need to meet new codes or standards, rehabilitation using a reline pipe maybe preferred versus replacement. Sizing of a reline culvert uses the same hydraulic flow design criteria as that of a new culvert however as the reline culvert is meant to be inserted into an existing culvert or host pipe, reline installation requires the grouting of the annular space between the host pipe and the surface of reline pipe (typically using a low compression strength grout) so as to prevent or reduce seepage and soil migration. Grouting also serves as a means in establishing a structural connection between the liner, host pipe and soil. Depending on the size and annular space to be filled as well as the pipe elevation between the inlet and outlet, grouting maybe required to be performed in multiple stages or "lifts". If multiple lifts are required, then a grouting plan is required which defines the placement of grout feed tubes, air tubes, type of grout to be used and if injecting or pumping grout then the required developed pressure for injection. As the diameter of the reline pipe will be smaller than the host pipe, the cross-sectional flow area will be smaller. By selecting a reline pipe with a very smooth internal surface, with an approximate Hazen-Williams Friction Factor, C, value of between 140–150, the decreased flow area can be offset and hydraulic flow rates potentially increased by way of reduced surface flow resistance. Examples of pipe materials with high C-factors are high-density polyethylene (150) and polyvinyl chloride (140). [8]

Environmental impacts

This culvert has a natural surface bottom connecting wildlife habitat. Aquatic Organism Passage Culvert.jpg
This culvert has a natural surface bottom connecting wildlife habitat.

Safe and stable stream crossings can accommodate wildlife and protect stream health, while reducing expensive erosion and structural damage. Undersized and poorly placed culverts can cause problems for water quality and aquatic organisms. Poorly designed culverts can degrade water quality via scour and erosion, as well as restrict the movement of aquatic organisms between upstream and downstream habitat. Fish are a common victim in the loss of habitat due to poorly designed crossing structures.

Culverts that offer adequate aquatic organism passage reduce impediments to movement of fish, wildlife, and other aquatic life that require instream passage. Poorly designed culverts are also more apt to become jammed with sediment and debris during medium to large scale rain events. If the culvert cannot pass the water volume in the stream, then the water may overflow over the road embankment. This may cause significant erosion, ultimately washing out the culvert. The embankment material that is washed away can clog other structures downstream, causing them to fail as well. It can also damage crops and property. A properly sized structure and hard bank armoring can help to alleviate this pressure.

Aquatic organism passage compatible culvert replacement in Franklin, Vermont, just upstream from Lake Carmi Aquatic Organsim Passage Culvert Replacement.jpg
Aquatic organism passage compatible culvert replacement in Franklin, Vermont, just upstream from Lake Carmi

Culvert style replacement is a widespread practice in stream restoration. Long-term benefits of this practice include reduced risk of catastrophic failure and improved fish passage. If best management practices are followed, short-term impacts on the aquatic biology are minimal. [9]

Fish passage

While the culvert discharge capacity derives from hydrological and hydraulic engineering considerations, [10] this results often in large velocities in the barrel, creating a possible fish passage barrier. Critical culvert parameters in terms of fish passage are the dimensions of the barrel, particularly its length, cross-sectional shape, and invert slope. The behavioural response by fish species to culvert dimensions, light conditions, and flow turbulence may play a role in their swimming ability and culvert passage rate. There is no simple technical means to ascertain the turbulence characteristics most relevant to fish passage in culverts, but it is understood that the flow turbulence plays a key role in fish behaviour. [11] [12] The interactions between swimming fish and vortical structures involve a broad range of relevant length and tine scales. [13] Recent discussions emphasised the role of secondary flow motion, considerations of fish dimensions in relation to the spectrum of turbulence scales, and the beneficial role of turbulent structures provided that fish are able to exploit them. [11] [14] [15] [16] [17] [18] [19] The current literature on culvert fish passage focused mostly on fast-swimming fish species, but a few studies argued for better guidelines for small-bodied fish including juveniles. [16] Finally, a solid understanding of turbulence typology is a basic requirement to any successful hydraulic structure design conducive of upstream fish passage. [20]

Minimum energy loss culverts

Culvert size relative to a person Culvert pipe (8242090899).jpg
Culvert size relative to a person

In the coastal plains of Queensland, Australia, torrential rains during the wet season place a heavy demand on culverts. The natural slope of the flood plains is often very small, and little fall (or head loss) is permissible in the culverts. Researchers developed and patented the design procedure of minimum energy loss culverts which yield small afflux. [21] [22] [23]

A minimum energy loss culvert or waterway is a structure designed with the concept of minimum head loss. The flow in the approach channel is contracted through a streamlined inlet into the barrel where the channel width is minimum, and then it is expanded in a streamlined outlet before being finally released into the downstream natural channel. Both the inlet and outlet must be streamlined to avoid significant form losses. The barrel invert is often lowered to increase the discharge capacity.

The concept of minimum energy loss culverts was developed by a shire engineer in Victoria and a professor at the University of Queensland during the late 1960s. [24] While a number of small-size structures were designed and built in Victoria, some major structures were designed, tested and built in south-east Queensland.

Forestry

In forestry, proper use of cross-drainage culverts can improve water quality while allowing forestry operations to continue.

See also

Notes

  1. Taylor, Karl (2010). "Thacka Beck Flood Alleviation Scheme, Penrith, Cumbria- Measured Building Survey of Culverts". Oxford Archaeology North.
  2. 1 2 3 4 Turner-Fairbank Highway research Center (1998). "Hydraulic Design of Highway Culverts" (PDF), Report #FHWA-IP-85-15 U.S. Department of Transportation, Federal Highway Administration, McLean, Virginia.
  3. Wild, Thomas C. (2011). "Deculverting: reviewing the evidence on the 'daylighting' and restoration of culverted rivers". Water and Environment Journal. 25 (3): 412–421. doi:10.1111/j.1747-6593.2010.00236.x.
  4. 1 2 Alberta Transportation (2004). "DESIGN GUIDELINES FOR BRIDGE SIZE CULVERTS" (PDF), Original Document 1995 Alberta Transportation, Technical Standards Branch, Government of the Province of Alberta
  5. Department of Interior Bureau of Land Management (2006). "Culvert Use, Installation, and Sizing" Chapter 8 (PDF), Low Volume Engineering J Chapter 8, blm.gov/bmp.
  6. Environmental Protection Agency EPA Management (2003-7-24). "Culverts-Water" NPS Unpaved Roads Chapter 3 (PDF), "CULVERTS" epa.gov.
  7. 1 2 Architectural Record CEU ENR (2013). "Stormwater Management Options and How They Can Fail" (Online Education Course), McGraw Hill Construction Architectural Record-engineering News Record.
  8. Plastic Pipe Institute-Handbook of Polyethylene Pipe, First Edition Copy 2006
  9. Lawrence, J.E., M.R. Cover, C.L. May, and V.H. Resh. (2014). "Replacement of Culvert Styles has Minimal Impact on Benthic Macroinvertebrates in Forested, Mountainous Streams of Northern California". Limnologica. 47: 7–20. arXiv: 1308.0904 . doi:10.1016/j.limno.2014.02.002.CS1 maint: multiple names: authors list (link)
  10. Chanson, H. (2004). The Hydraulics of Open Channel Flow: An Introduction. Butterworth-Heinemann, 2nd edition, Oxford, UK. ISBN   978-0-7506-5978-9.
  11. 1 2 Nikora, V.I., Aberle, J., Biggs, B.J.F., Jowett, I.G., Sykes, J.R.E. (2003). "Effects of Fish Size, Time-to-Fatigue and Turbulence on Swimming Performance: a Case Study of Galaxias Maculatus". Journal of Fish Biology. 63 (6): 1365–1382. doi:10.1111/j.1095-8649.2003.00241.x.CS1 maint: multiple names: authors list (link)
  12. Wang, H., Chanson, H. (2017). "How a better understanding of Fish-Hydrodynamics Interactions might enhance upstream fish passage in culverts". Civil Engineering Research Report No. CE162: 1–43.CS1 maint: multiple names: authors list (link)
  13. Lupandin, A.I. (2005). "Effect of flow turbulence on swimming speed of fish". Biology Bulletin. 32 (5): 461–466. doi:10.1007/s10525-005-0125-z.
  14. Papanicolaou, A.N., Talebbeydokhti, N. (2002). "Discussion of Turbulent open-channel flow in circular corrugated culverts". Journal of Hydraulic Engineering. 128 (5): 548–549.CS1 maint: multiple names: authors list (link)
  15. Plew, D.R., Nikora, V.I., Larne, S.T., Sykes, J.R.E., Cooper, G.G. (2007). "Fish swimming speed variability at constant flow: Galaxias maculatus". New Zealand Journal of Marine and Freshwater Research. 41 (2): 185–195. doi:10.1080/00288330709509907.CS1 maint: multiple names: authors list (link)
  16. 1 2 Wang, H., Chanson, H., Kern, P., Franklin, C. (2016). "Culvert Hydrodynamics to enhance Upstream Fish Passage: Fish Response to Turbulence". 20th Australasian Fluid Mechanics Conference, Perth, Australia. Paper 682: 1–4.CS1 maint: multiple names: authors list (link)
  17. Cabonce, J., Fernando, R., Wang, H., Chanson, H. (2017). Using Triangular Baffles to Facilitate Upstream Fish Passage in Box Culverts: Physical Modelling. Hydraulic Model Report No. CH107/17, School of Civil Engineering, The University of Queensland, Brisbane, Australia, 130 pages. ISBN   978-1-74272-186-6.CS1 maint: multiple names: authors list (link)
  18. Wang, H., Chanson, H. (2017). "Baffle Systems to Facilitate Upstream Fish Passage in Standard Box Culverts: How About Fish-Turbulence Interplay?". 37th IAHR World Congress, IAHR & USAINS, Kuala Lumpur, Malaysia. 3: 2586–2595.CS1 maint: multiple names: authors list (link)
  19. Wang, H., Chanson, H. (2018). "Modelling Upstream Fish Passage in Standard Box Culverts: Interplay between Turbulence, Fish Kinematics, and Energetics" (PDF). River Research and Applications. 34 (3): 244–252. doi:10.1002/rra.3245.CS1 maint: multiple names: authors list (link)
  20. Chanson, H. (2019). "Utilising the Boundary Layer to Help Restore the Connectivity of Fish Habitats and Populations. An Engineering Discussion". Ecological Engineering. 141 (105613): 1–5. doi:10.1016/j.ecoleng.2019.105613.
  21. Apelt, C.J. (1983). "Hydraulics of minimum energy culverts and bridge waterways," Australian Civil Engineering Transactions, CE25 (2) : 89-95. Available on-line at: University of Queensland.
  22. Apelt, C.J. (1994). "The Minimum Energy Loss Culvert" (videocassette VHS colour), Dept. of Civil Engineering, University of Queensland, Australia.
  23. Apelt, Colin. (2011). "The Minimum Energy Loss Culvert, Redcliffe" (prepared speech: Award of Engineering Heritage National Landmark By Engineering Heritage Australia on 29 June 2011). https://www.engineersaustralia.org.au/sites/default/files/shado/Learned%20Groups/Interest%20Groups/Engineering%20Heritage/EHA%20Queensland/McKay%20Landmark/CJA%20Speech-MEL%20Redcliffe.pdf
  24. See:

Related Research Articles

Flood Overflow of water that submerges land that is not normally submerged

A flood is an overflow of water that submerges land that is usually dry. In the sense of "flowing water", the word may also be applied to the inflow of the tide. Floods are an area of study of the discipline hydrology and are of significant concern in agriculture, civil engineering and public health.

Dam A barrier that stops or restricts the flow of surface or underground streams

A dam is a barrier that stops or restricts the flow of water or underground streams. Reservoirs created by dams not only suppress floods but also provide water for activities such as irrigation, human consumption, industrial use, aquaculture, and navigability. Hydropower is often used in conjunction with dams to generate electricity. A dam can also be used to collect water or for storage of water which can be evenly distributed between locations. Dams generally serve the primary purpose of retaining water, while other structures such as floodgates or levees are used to manage or prevent water flow into specific land regions. The earliest known dam is the Jawa Dam in Jordan, dating to 3,000 BC.

Hydraulic jump situation in a stream where water briefly flows upwards (but still downstream) due to its kinetic energy

A hydraulic jump is a phenomenon in the science of hydraulics which is frequently observed in open channel flow such as rivers and spillways. When liquid at high velocity discharges into a zone of lower velocity, a rather abrupt rise occurs in the liquid surface. The rapidly flowing liquid is abruptly slowed and increases in height, converting some of the flow's initial kinetic energy into an increase in potential energy, with some energy irreversibly lost through turbulence to heat. In an open channel flow, this manifests as the fast flow rapidly slowing and piling up on top of itself similar to how a shockwave forms.

Weir barrier across a river designed to alter its flow characteristics

A weir or low head dam is a barrier across the width of a river that alters the flow characteristics of water and usually results in a change in the height of the river level. There are many designs of weir, but commonly water flows freely over the top of the weir crest before cascading down to a lower level.

Fish ladder structure that allows fish and other organisms to pass artificial or natural barriers at watercourses

A fish ladder, also known as a fishway, fish pass or fish steps, is a structure on or around artificial and natural barriers to facilitate diadromous fishes' natural migration as well as movements of potamodromous species. Most fishways enable fish to pass around the barriers by swimming and leaping up a series of relatively low steps into the waters on the other side. The velocity of water falling over the steps has to be great enough to attract the fish to the ladder, but it cannot be so great that it washes fish back downstream or exhausts them to the point of inability to continue their journey upriver.

Tidal bore A water wave traveling upstream a river or narrow bay due to incoming tide

A tidal bore, often simply given as bore in context, is a tidal phenomenon in which the leading edge of the incoming tide forms a wave of water that travels up a river or narrow bay against the direction of the river or bay's current.

Spillway Structure for controlled release of flows from a dam or levee

A spillway is a structure used to provide the controlled release of flows from a dam or levee into a downstream area, typically the riverbed of the dammed river itself. In the United Kingdom, they may be known as overflow channels. Spillways ensure that the water does not overflow and damage or destroy the dam.

Hydraulic head Specific measurement of liquid pressure above a geodetic datum

Hydraulic head or piezometric head is a specific measurement of liquid pressure above a vertical datum.

Low-water crossing bridge when the water flow is low

A low-water crossing provides a bridge when water flow is low. Under high-flow conditions, water runs over the roadway and precludes vehicular traffic. This approach is cheaper than building a bridge to raise the level of the road above the highest flood stage of a river, particularly in developing countries or in semi-arid areas with rare high-volume rain. Low-water crossings can be dangerous when flooded.

Training or entrance training refers to coastal structures built to constrain a river discharging across a littoral coast so that it discharges only where desired. Untrained entrances on sandy coasts tend to move widely and violently to discharge into the ocean, often upsetting those enjoying land nearby. With many cities constructed close to rivers, such management has historically been considered a necessary course of action, even though ecologically, non-intervention would be better and more sustainable.

In hydraulic engineering, a nappe is a sheet or curtain of water that flows over a weir or dam. The upper and lower water surface have well-defined characteristics that are created by the crest of a dam or weir. Both structures have different features that characterize how a nappe might flow through or over impervious concrete structures. Hydraulic engineers distinguish these two water structures in characterizing and calculating the formation of a nappe. Engineers account for the bathymetry of standing bodies or moving bodies of water. An appropriate crest is built for the dam or weir so that dam failure is not caused by nappe vibration or air cavitation from free-overall structures.

A drop structure, also known as a grade control, sill, or weir, is a manmade structure, typically small and built on minor streams, or as part of a dam's spillway, to pass water to a lower elevation while controlling the energy and velocity of the water as it passes over. Unlike most dams, drop structures are usually not built for water impoundment, diversion or raising the water level. Mostly built on watercourses with steep gradients, they serve other purposes such as water oxygenation and erosion prevention.

Alden Research Laboratory

Alden Research Laboratory, Inc. (Alden) was founded in 1894 as part of Worcester Polytechnic Institute (WPI). It is the oldest continuously operating hydraulic laboratory in the United States. Today, as an independent entity, Alden has become a recognized leader in the field of fluid dynamics research and development.

Bridge scour

Bridge scour is the removal of sediment such as sand and gravel from around bridge abutments or piers. Scour, caused by swiftly moving water, can scoop out scour holes, compromising the integrity of a structure.

Hubert Chanson is a hydraulic engineering and applied fluid mechanics academic. Since 1990 he has worked at the University of Queensland.

Reynolds number Dimensionless quantity that is used to help predict fluid flow patterns

The Reynolds number is the ratio between the inertial forces in a fluid and the viscous forces. A fluid in motion tends to behave as sheets or layers of infinitely small thicknesses sliding relative to each other. The viscosity of a fluid is the resistance to flow, which in turn translates as resistance to shear between the layers. The inertia (momentum) of the fluid is a dynamic function of its mass and speed, or resistance to a change in motion, which works to create shear between the fluid layers. This shear is created as a fluid encounters viscous resistance from an outside obstacle, such as the inner wall of a pipe, where flow is slowed by drag against the surface while remaining mostly unimpeded near the center of the pipe. For any given fluid, as flow rate increases, at a certain point the inertial forces begin to overcome the viscous forces; the smoothly-sliding layers of the fluid begin to roll past each other, and rough, turbulent flow results. Reynolds number is used to predict both where and at what scale in the flow this transition will happen for any given fluid in any given flow situation.

Eprapah Creek is a sub-tropical stream located in Redland City close to Brisbane in South East Queensland, Australia.

Stepped spillway

A stepped spillway is a spillway with steps on the spillway chute to assist in the dissipation of the kinetic energy of the descending water. This eliminates or reduces the need for an additional energy dissipator, such as a body of water, at the end of the spillway downstream.

Open channel spillways are dam spillways that utilize the principles of open-channel flow to convey impounded water in order to prevent dam failure. They can function as principal spillways, emergency spillways, or both. They can be located on the dam itself or on a natural grade in the vicinity of the dam.

References