PERFORATED BOX CULVERT

Abstract

A box culvert is disclosed having a top panel, a first side panel, and a second side panel, and a base panel. The first side panel and second side panel extend from the top panel to the base panel. The base panel is configured to have a plurality of sealed holes. The sealed holes are configured to be unsealed. Installing the box culvert in a riverway allows a road or trail thereover, and water passage therethrough. Opening of a specific amount, position, and size of sealed holes creates unsealed holes in the base panel. The unsealed holes allows groundwater upwelling therethrough, configured specifically to the waterway. The upwelling caused by removal of the specific plugs promotes aquatic habitat, contributes to water quality improvements, and ameliorates disruption from the insertion of the box culvert.

Description

FIELD

This disclosure relates to a box culvert for water passage.

BACKGROUND

Culverts are physical structures placed in a waterway to allow a path thereover while allowing passage of water therethrough. The waterway may be drainage water, river water, streams, or the like. By installing a culvert, water may flow through the culvert, leaving a road or trail to pass over the water unencumbered.

Known culverts are manufactured in different cross-sectional shapes, physical sizes, and materials. Most often, culverts are made using metal—such as steel—or poured concrete. The specific height, width, depth, and shape of a culvert may be based on the size of trail or waterway, the natural landscape, and any budgetary concerns. Culverts having a generally square or rectangular cross section are often referred to as box culverts. Box culverts may generally be categorized as open-bottom or closed-bottom. A closed-bottom culvert has a base panel of concrete that sits atop a waterway base, while an open-bottom culvert does not have any base panel.

As well, some known box culvert designs have holes in the bottom to capture specific types of material as it passes through, thereby creating a habitat that is desired by particular species.

Installation of culverts (and culverts themselves) can often disrupt natural habitats of watercourses, plants and wildlife. Accordingly, a culvert to promote natural habitats of watercourses, plants and wildlife is desired.

SUMMARY

A box culvert for installation in a waterway or river is disclosed herein. The box culvert is a closed bottom box culvert, meaning the box culvert has a base panel extending across a floor of the waterway or river. The base panel may be configured to have a plurality of sealed holes. The sealed holes may be configured to be unsealed. Based on a particular application or parameter of the waterway for installation, the sealed holes of the base panel of the box culvert may be unsealed. Removal of the seals allows for groundwater upwelling through the box culvert.

Aspects of the present disclosure relate to a box culvert, comprising: a top panel; a base panel; and a first and second side panel extending from the top panel to the bottom panel, wherein the base panel has a plurality of sealed holes, each hole configured to be unsealed.

Other aspects relate to a method of installing a box culvert, comprising: providing a box culvert having sealed holes in a base panel; selecting, based on a determination for an installation site, at least one sealed hole to be opened; opening the seal of the selected at least one sealed hole to be opened; and installing the box culvert.

BRIEF DESCRIPTION OF DRAWINGS

Embodiments will be described, by way of example only, with reference to the accompanying figures in which:

FIG. 1 illustrates a closed-bottom box culvert;

FIG. 2 illustrates a closed-bottom box culvert having sealed holes;

FIG. 3 illustrates the closed-bottom box culvert of FIG. 2 with all holes unsealed;

FIG. 4 illustrates the closed-bottom box culvert of FIG. 2 having some holes unsealed;

FIG. 5A illustrates a cross section of the closed-bottom box culvert of FIG. 2 according to a first embodiment;

FIG. 5B illustrates a cross section of the closed-bottom box culvert of FIG. 2 according to a second embodiment;

FIG. 5C illustrates a cross section of the closed-bottom box culvert of FIG. 2 according to a third embodiment;

FIG. 6 illustrates the closed-bottom box culvert of FIG. 4 in an installed position;

FIG. 7 illustrates a method of installing the closed-bottom box culvert of FIG. 2; and

FIG. 8 illustrates a cross-sectional view of an installation of the box culvert of FIG. 4 into a stream bed.

DETAILED DESCRIPTION

FIG. 1 is a box culvert 100 known in the prior art. Box culvert 100 comprises a base panel 110, a top panel 120, a first side panel 130, and a second side panel 140 (collectively “panels”). Box culvert 100 may have a height h, width w, and depth d. First side panel 130 and second side panel 140 may extend from top panel 120 to base panel 110 to form passage 150. The connection between panels defines a passage 150 for allowance of water therethrough and a road over top panel 120. Although references may be made throughout this disclosure to rivers, it would be known that any culvert may be used for other waterways or storm drains. Similarly, while roads may be mentioned, railways, paths, or any other feature may be placed over top panel 120. A box culvert is considered an open-box culvert if it does not include a base panel 110.

FIG. 2 illustrates a closed-bottom box culvert 500. Box culvert 500 includes base panel 510, top panel 520, first side panel 530, second side panel 540. First side panel 530 and second side panel 540 may extend from top panel 520 to base panel 510 to form passage 560. Specific environmental parameters, such as the size of the waterway to go through passage 560, or the road to go over top panel 520 may determine the specific height, width and depth of box culvert 500. According to some embodiments, base panel 510 may extend deeper into a riverbed at river input and output to form cut-off walls 550.

Base panel 510, top panel 520, first side panel 530, second side panel 540, and cut-off walls 550 may be constructed from the same or different materials. Example materials are concrete, aluminum, stainless steel, plastics, or any other suitably rigid material. If box culvert 500 is made using concrete, the concrete may be reinforced, using structural material such as rebar. Base panel 510 may distribute the weight of top panel 520, first side panel 530, and second side panel 540 along the riverbed on which the box culvert 500 in installed.

Box culvert 500 may have an inlet section and an outlet section of passage 560. Cut-off walls 550 may be placed, respectively, under inlet section and outlet section of passage 560. Cut-off walls 550 may be solid, and may further include vertical pins that are pinned and grouted to inlet and outlet section of passage 560. Cut-off walls 550 may be connected to base panel 510 such that no ground water can seep through cut-off walls 550 and into or out of the space below base panel 510 and between cut-off walls 550. Inlet cut-off wall may also include one or more openings for groundwater to travel through inlet cut-off wall and into the space below base panel 510 and between cut-off walls 550. One or more openings may include perforations, channels, holes or other features that allow groundwater to travel through inlet cut-off wall. Outlet cut-off wall may be impermeable, preventing groundwater from travelling through outlet cut-off wall.

Box culvert 500 has sealed holes 512 in base panel 510. Base panel 510, as illustrated, is configured with a plurality of sealed holes 512 having variable diameters and positions. Sealed holes 512 may be identified using a coordinate system. Sealed holes 512 may have predetermined successively smaller diameters. For example, sealed holes 512 may be manufactured in base panel 510 to be 60 cm wide, 50 cm wide, 40 cm wide, 30 cm wide, 20 cm wide, 15 cm wide, 10 cm wide, 7.5 cm wide and 5 cm wide. While the illustrated example of box culvert 500 shows holes in decreasing size, according to some embodiments, the holes may be in a different order.

Sealed holes 512 of box culvert 500 may be sealed using plugs 514. Plugs 514 may be made of a natural material such as wood or cork, or a synthetic material such as concrete, rubber, plastic or Bentonite. In some embodiments, plugs 514 may also be made of concrete, rubber, or foam. Plugs 514 may be configured to be temporarily or permanently unsealed. Plugs 514 may be configured having a shape complementary to sealed hole 512, or may be tapered. For example, plugs 514 may be cylindrical, conical, semi-conical or convex. Plugs 514 that are tapered may provide additional force on base panel 510 to maintain the sealed configuration. In some embodiments, plugs 514 may vary in diameter, shape, length, orientation, and composition, such that plugs 514 are not identical. Plugs 514 may be friction fit into sealed holes, or may be inserted with a sealant or adhesive such as wax, caulk, or any other suitable material. Plug 514 may include handles or any other implement to assist with plug removal.

Sealed hole 512 may also be partially unsealed by only partially removing plug 514. For example, sealed hole 512 may contain a nested plug, such that an inner plug may be removed to partially unseal the hole and form unsealed hole 516. An inner ring plug may further be removed from unsealed hole 516 to further unseal unsealed hole 516, and an outer ring plug may further be removed from unsealed hole 516 to fully unseal unsealed hole 516. It will be appreciated that different configurations, with fewer or more inner plugs or inner ring plugs, may be possible.

Box culvert 500 may be manufactured at a location remote from the site in which box culvert 500 may be ultimately installed. Alternatively, parts of box culvert 500 may be manufactured at several locations, such as at a manufacturing facility and also at the installation site.

Box culvert 500 may be manufactured using a pourable curing semisolid and negative mold. For example, box culvert 500 may be manufactured by pouring concrete into a pre-form structure. The preform structure may be shaped to a negative of the intended constructed base panel 510, and include plugs 514 temporarily affixed and positioned in a desired arrangement. Once the concrete is poured, plugs 514 may be cast into the base panel 510 for later removal.

According to an embodiment, sealed holes 512 may be formed while casting base panel 510. In other embodiments, sealed holes 512 may be drilled into base panel 511 and plugs 514 may be temporarily affixed and positioned in base panel 510.

Box culvert 500 may be manufactured in multiple steps. For example, the base panel 510 may be initially cast. After the base panel 510 of the box culvert 500 is cast, the first side panel 530 and the second side panel 540 can be cast, connected to base panel 510. Once in place, the top panel 520 may be cast connected to and extending between the first side panel 530 and the second side panel 540.

According to another embodiment, box culvert 500 may be manufactured as a clamshell-type precast structure. For example, the first side panel 530 may be cast, connected to top panel 520. Second side panel 540 may also be cast, but connected to base panel 510. First side panel 530 and top panel 520 may then be connected to second side panel 520 and base panel 510.

Cut-off walls 550 may be manufactured as separate pieces from the rest of box culvert 500, such as base panel 510. Cut-off walls 550 may be installed first into stream or river bed. It will be appreciated that the stream or river must be dammed first before cut-off walls 550 may be installed. For example, cut-off walls may be embedded into trenches dug into stream or river bed sized to accommodate cut-off walls 550. Base panel 510 may be place on top of cut-off walls 550 and affixed using the methods discussed above. Since base panel 510 may be level, cut-off walls 550 may be embedded into trenches such that cut-off walls 550 are also level. For example, a fine layer of gravel may be placed under the bottom of cut-off walls 550 in trenches to ensure that cut-off walls remain level.

Base panel 510, as well as the other panels of box culvert 500, may be supported by cut-off walls 550. However, since cut-off walls 550 may only provide support at the inlet and outlet sides of base panel 510, base panel 510 may also be supported between the inlet and outlet sides. As will be discussed in greater detail below, a clear stone gravel pack may be installed between cut-off walls 550 and beneath base panel 510. Clear stone gravel pack may be layered such that it is also level with the tops of cut-off walls 550, and can thus provide support for base panel 510, as well as the other panels of box culvert 500, between the inlet and outlet sides. Base panel 510 may alternatively be otherwise supported.

Cut-off walls 550 may be sealed with suitable cohesive soils (i.e. clay) and/or a waterproof sealant, such as grout. For example, downstream or outlet cut-off wall 550 may be sealed with a waterproof sealant.

FIG. 3 illustrates a closed bottom box culvert 501. Similar to the closed bottom box culvert 500, box culvert 501 includes base panel 511, top panel 521, first side panel 531, second side panel 541, and cut-off walls 551. First side panel 531 and second side panel 541 may extend from top panel 521 to base panel 511 to form passage 561. Box culvert 501 may have been formed from box culvert 500 (as illustrated in FIG. 2). In box culvert 501, all plugs 514 from box culvert 500 have been removed, creating unsealed holes 516. Plugs 514 may be removed by pulling plugs 514 out of sealed holes 512, pushing plugs through sealed holes 512, drilling plugs 514 out of sealed holes 512, or any other means.

Box culvert 501 may present advantages over a traditional open and closed bottom box culvert designs. In a traditional box culvert (such as box culvert 100 of FIG. 1), natural life above the base panel 110 may be displaced. Unsealed holes 516 allow for aquatic life to continue to exist by providing natural conditions. Further, unsealed holes 516 allow for groundwater upwelling and drainage, while maintaining the integrity of base panel 510. Use of a cut-off wall 550 promotes ground water upwelling into unsealed holes 516 by creating hydrostatic pressure around box culvert 501. An increase in upwelling through holes 512 allows for increased aquatic life, increased temperature gradient, and improved drainage. Unsealed holes 516 may provide contact for conductive thermal transfer between riverbed and river.

However, increasing the number of unsealed holes 516 may still lead to a decrease in structural integrity in box culvert 501. For example, in some embodiments up to 50% of the area of base panel 511 may be perforated by unsealed holes 516 and still provide structural integrity in box culvert 501, with no required change to the preparation of base panel 511. Additionally, groundwater upwelling may not be desirable or natural at all unsealed holes 516 locations across base panel 511. This may lead to earlier replacement of box culvert 501.

FIG. 4 illustrates a closed bottom box culvert 502. Box culvert 502 includes base panel 518, top panel 522, first side panel 532, and second side panel 542. Base panel 518 includes cut-off walls 552. First side panel 532 and second side panel 542 may extend from top panel 522 to base panel 518 to form passage 562.

Box culvert 502 contains both unsealed holes 516 and sealed holes 512. Box culvert 502 may be formed using box culvert 500 (as illustrated in FIG. 2). Based on a determination, the necessary plugs 514 in sealed holes 512 may be identified and removed, forming unsealed holes 516. Sealed hole 512 may have its plug 514 physically removed or knocked out using mechanical means, depending on type of plug material and site conditions.

The determination of which plugs 514 to remove may be based on multiple characteristics measured at an installation site. For example, a user may measure water depth, water speed, water temperature, nature presence, and ground hardness at predetermined positions across a river. Based on these measurements, the natural groundwater upwelling at specific locations along a riverbed may be determined. Using this information, the specific plugs 514 to remove may be identified. For example, if no natural groundwater upwelling is observed and/or determined, the sealed hole 512 may remain plugged. If a small amount of groundwater upwelling is observed and/or determined, a smaller sealed hole 512 may have its plug 514 removed. Similarly, if a large amount of groundwater upwelling is observed and/or determined, a larger sealed hole 512 may have its plug removed. Further, the determination may be based on the weight of box culvert 502. It will be appreciated that plug 514 may be removed from sealed hole 512 to create conditions for groundwater upwelling in box culvert 502.

Groundwater upwelling may be determined to support the opening of sealed holes 512 to maximize performance of box culvert 502. Areas of groundwater upwelling may be determined based on stream assessment and natural characteristics like watercress locations, visual upwellings and differences in surface water temperature. For example, testing for groundwater upwelling may be achieved using streambed piezometers to determine groundwater conditions and flow direction, which may also aid in the determination of which plugs 514 should be removed. Geotechnical data acquired from borehole observations may assist in determining groundwater potential and typical elevation of groundwater in relation to road and creek level elevations. This geotechnical information may be used to determine the elevation of box culvert 502 relative to the streambed. The elevation of base panel 518 may be set below the typical height of groundwater and at least 300 mm below the existing streambed. Groundwater input to the waterway may be within the bank and bed of the watercourse so that when base panel 518 is placed below the streambed elevation the natural upward movement of groundwater may be forced through unsealed holes 516 in optimal locations of base panel 518. The configuration of sealed holes 512, relative to the configuration of unsealed holes 516, may allow for controlled performance of box culvert 502. As can be seen above, controlled performance of box culvert is determined from geotechnical data, elevation of groundwater, and habitat features preferred by desired aquatic species.

Box culvert 502 may provide a benefit for aquatic life upon installation. By having unsealed holes 516 in optimal locations, groundwater upwelling may occur in a similar fashion to the habitat had box culvert not been installed. Thereby, aquatic life living in and travelling through the culvert may observe minimal change in their habitat, including water temperature, water quality, velocity and flow. In addition, groundwater upwelling may also lead to spawning for groundwater-dependent species (e.g. Brook trout). Controlled performance of box culvert may also promote upwelling in locations that would not have previously experienced upwelling, thereby creating a desired habitat in areas that were previously not supported.

As discussed above, box culvert 502 may have an inlet section and an outlet section of passage 562. Cut-off walls 552 may be placed, respectively, under inlet section and outlet section of passage 562. Cut-off walls 552 may be solid, and may further include vertical pins that are pinned and grouted to inlet and outlet sections of passage 562.

In one embodiment, a technician may determine the configuration of sealed holes 512, relative to the configuration of unsealed holes 516, based on an installation site mapping. The technician may generate installation site mapping based on a hydrogeology report describing the installation site, Global Positioning System (GPS) measurements collected at installation site, and the physical characteristics of box culvert 502.

A hydrogeologist may, for example, prepare hydrogeology report, based on hydrogeology analyses performed at the installation site. Hydrogeologist may record the hydrogeological characteristics of the installation site described above, such as the locations of natural groundwater upwelling along the riverbed of installation site, the elevation of groundwater in relation to road and creek level elevation, and natural characteristics like watercress locations, visual upwellings and differences in surface water temperature. Hydrogeology report may also recommend a location and orientation of box culvert 502 relative to installation site based on the hydrogeological characteristics of installation site.

The technician may use a GPS device to log the hydrogeological characteristics of installation site described in the hydrogeology report. In particular, the technician may physically identify the hydrogeological characteristics from hydrogeology report at installation site and collect GPS measurements for each of the hydrogeological characteristics. The technician may log the location of a hydrogeological characteristic of installation site using a GPS measurement of that hydrogeological characteristic. It will be appreciated that the technician may also optionally identify hydrogeological characteristics of the installation site beyond those identified in hydrogeology report, such that the technician may also use GPS device to collect GPS measurements for, and identify the location of, each of these additional hydrogeological characteristics.

The location of a hydrogeological characteristic at the installation site may represent a location at which it would be desirable to allow or prevent passage of water through the floor of box culvert 502. The location of the hydrogeological characteristic may thus represent a location at which it would be desirable to locate sealed holes 512 or unsealed holes 516 of box culvert 502, depending on the hydrogeological characteristic of installation site.

A technician may generate installation site mapping using the locations of hydrogeological characteristics, as well as whether the location of each hydrogeological characteristic represents a location at which it would be desirable to locate one or more sealed holes 512 or one or more unsealed holes 516. For example, a first set of hydrogeological characteristics may correspond to locations where a small or large amount of groundwater upwelling is observed, and so technician may recommend unsealed holes 516 of appropriate sizes at the locations of first set of hydrogeological characteristics. A second set of hydrogeological characteristics may correspond to locations where no groundwater upwelling is observed, and so technician may recommend sealed holes 512 at the locations of second set of hydrogeological characteristics. The technician may record these recommendations in installation site mapping.

The technician may also record in installation site mapping a recommended location and orientation of box culvert 502 relative to the installation site. The technician may record in installation site mapping the recommended location and orientation of box culvert 502 relative to installation site by indicating preferred GPS locations of two or more corners of box culvert 502. It will be appreciated that technician may also record in installation site mapping the recommended location and orientation of box culvert 502 relative to installation site using some other suitable method.

In one embodiment, the technician may generate installation site mapping using computer software. The technician may input into installation site mapping software GPS measurements for each of the hydrogeological characteristics identified by the hydrogeology report and at installation site. In addition to GPS measurements, the technician may input into installation site mapping software a recommendation for whether a sealed hole or an unsealed hole should be located at the GPS measurement for each hydrogeological characteristic. In further embodiments, the technician may also input into the installation site mapping software a recommendation for the size of the unsealed hole or whether multiple unsealed holes may be required. The technician may further manually identify a specific number or area of unsealed holes that may be required. Recommendations for the size and number of unsealed holes may be based on the geotechnical data, elevation of groundwater, and habitat features preferred by desired aquatic species.

The technician may input into installation site mapping software the recommended orientation and location of box culvert 502, such as by inputting the preferred GPS locations of two or more corners of box culvert 502. As well, the technician may also input into installation site mapping software the physical characteristics of box culvert 502. For example, the technician may input a serial number, quick response (QR) code or other identifier of box culvert 502 into installation mapping software, or technician may select the physical characteristics of box culvert 502 from a list of possible box culvert configurations. In this way, technician may enable installation site mapping software to identify the physical characteristics of box culvert 502. Alternatively, technician may manually input into installation site mapping software the physical characteristics of box culvert 502.

In further embodiments, instead of the technician inputting a recommendation for whether a sealed hole or an unsealed hole should be located at the GPS measurement for each hydrogeological characteristic, the technician may input into installation site mapping software descriptive information for each hydrogeological characteristic. For example, descriptive information may include whether the hydrogeological characteristic corresponds to a location where a small, medium or large amount of groundwater upwelling is observed or where no groundwater upwelling is observed. The technician may select descriptive information from a list of possible descriptive information categories in installation site mapping software. For each hydrogeological characteristic, installation site mapping software may automatically recommend whether a sealed hole 512 or an unsealed hole 516 should be formed in box culvert 502, based on the descriptive information associated with that hydrogeological characteristic. Installation site mapping software may include a lookup table correlating each descriptive information category in list of possible descriptive information categories with a recommendation for a sealed hole or an unsealed hole. In further embodiments, lookup table may also include a recommendation for the size of the unsealed hole and whether multiple unsealed holes are required.

The technician may run or execute installation site mapping software, such that installation site mapping software may automatically determine sealed holes 512 and unsealed holes 516 to be formed in box culvert 502, based on the inputs into installation site mapping software described above. For example, installation site mapping software may first determine the GPS locations of box culvert 502 based on the recommended orientation and location of box culvert 502 and the physical characteristics of box culvert 502, both input into installation site mapping software. The GPS locations of box culvert 502 may include the GPS location of two or more corners of box culvert 502, or the GPS locations of several points around the perimeter of box culvert 502. The GPS locations of box culvert 502 may also include the GPS locations of sealed holes 512, which may be unsealed to form unsealed holes 516 in box culvert 502. Installation mapping software may compare the GPS measurement for each hydrogeological characteristic to the GPS locations of sealed holes 512. For each hydrogeological characteristic that includes a recommendation for an unsealed hole, installation site mapping software may determine which sealed hole 512 is closest and can be unsealed to form unsealed hole 516 in box culvert 502. In some embodiments, installation site mapping software may also determine which multiple sealed holes 512 close to the GPS measurement for the hydrogeological characteristic, which can all be unsealed to form unsealed holes 516 in box culvert 502. Similarly, for each hydrogeological characteristic that includes a recommendation for a sealed hole, installation site mapping software may determine which sealed hole 512 is closest and should remained sealed. In this way, installation site mapping software may automatically determine sealed holes 512 and unsealed holes 516 to be formed in box culvert 502. It will be appreciated that installation site mapping software may automatically make this determination in a different order or using other method steps not described above.

It will be appreciated that technician or installation site mapping software may also manually determine sealed holes 512 and unsealed holes 516 to be formed in box culvert 502 based on the hydrogeology report describing the installation site, GPS measurements collected at installation site, and the physical characteristics of box culvert 502 and the surrounding environment.

In some embodiments, at least one of cut-off walls 552 may be include an opening. For example, cut-off wall 552 placed under inlet section of passage 562 may be an upstream or inlet cut-off wall. Box-culvert 502 may include one or more openings located in the uppermost half of inlet cut-off wall 552 to allow for waterflow into the bedding below box culvert 502. One or more openings located in cut-off wall 552 may include perforations to allow water to travel through inlet cut-off wall 552. The bedding may be clear stone bedding.

Cut-off wall 552 placed under outlet section of passage 562 may be a downstream or outlet cut-off wall. To ensure the lateral flow of groundwater, it may be desirable for groundwater in the bedding of the waterway to flow upward through unsealed holes 516 and into passage 562. This may be achieved by cut-off wall 552 remaining solid, and also by back-filling cut-off wall 552 with native or compacted cohesive material around its edge to ensure a seal that promotes upward flow through unsealed holes 516.

Base panel 518 may be layered with a suitable granular substrate, and groundwater may flow upward through both unsealed holes 516 and granular substrate. It will be appreciated that nominal sized stone is required to ensure that the formed creek bed remains in the culvert and tied into the upstream and downstream channel of box culvert 502. As well, granular substrate may allow free flow of groundwater based on the pore spacing within granular substrate. According to one embodiment, granular substrate may be sized based on hydraulics, such as the diameter and percentage of stone that may be required to ensure that substrate will not be flushed out of the culvert. Granular substrate may also need to be free of granular fines, such as clay and silt, to allow for groundwater movement through granular substrate from unsealed holes 516. For example, granular substrate may consist of nominal sized stone, such as large gravel, cobble, and boulder, with a lower percentage of medium to fine gravel and sand. Granular substrate may be a clear stone gravel pack.

FIG. 5A illustrates a cross-sectional view of base panel 518 along line A-A in a box culvert (such as box culvert 502), according to one embodiment. As may be seen, unsealed holes 516 and plugs 514 extend vertically from a top side of base panel 518 to a bottom side. As may be further observed, the two leftmost holes and the rightmost hole are unsealed holes 516. The remainder of holes in the row illustrated in the cross section are sealed holes 512 contain plugs 514. However, as illustrated, the configuration of other rows may be different.

While the illustrated plugs 514 extend from the top side to the bottom side of base panel 518, plugs 514 may be configured to only extend partially through the sealed hole 512.

Plugs 514 may be removed by pushing plugs 514 out of sealed holes 512, pulling plugs out of sealed holes 512, drilling plugs 514 out, or any other means.

FIG. 5B illustrates a cross-sectional view of base panel 518′ along line A-A in a box culvert (such as box culvert 502), according to another embodiment. In this embodiment, sealed holes 512′ having plugs 514′, and unsealed holes 516′ have been formed into base panel 518′ at an angle. While the illustrated sealed holes 512′ and unsealed holes 516′ are all shown having the same angle directed inwardly, each sealed hole 512′, plug 514′ and unsealed hole 516′ may be configured in base panel 518′ to have a unique and variable angle. For example, holes closer to first side panel 532 and second side panel 542 may have greater angles than those closer to the center of base panel 518′.

Similar to plugs 514, plugs 514′ may be removed by pushing, pulling, drilling, or any other means.

FIG. 5C illustrates a cross-sectional view of base panel 518″ along line A-A in a box culvert (such as box culvert 502), according to another embodiment. In this embodiment, sealed holes 512″ are sealed using knockout panels. Knockout panels 524 may be made of the same material as box culvert 502, or a different material that can be removed or partially removed, such as concrete, foam, rubber, and may include screens in unsealed holes 516.

Knockout panels 524 may be thinner than the base panel 518, such that sealed holes 512″ may be opened by drilling, hammering, jackhammering, or any other means. Use of a thinner material than base panel 518″ allows for easily unsealing sealed holes 512″ using less force than drilling through the entire base panel 518″.

FIG. 6 illustrates box culvert 502 in an installed position. As may be observed, river 612 is flowing through passage 562, while road 300 is positioned over top panel 522. Groundwater may come through unsealed holes 516, while it may not go through sealed holes 512.

In further embodiments, box culvert 502 may include variations of unsealed holes 516. For example, box culvert 502 may include screened unsealed holes 516 to deter fine sediments from settling inside unsealed holes 516. Box culvert 502 may also have conical unsealed holes 516 with a small diameter oriented at the top of base panel 518 to increase the velocity of upwelling groundwater. As well, box culvert 502 may include louver-type unsealed holes 516.

FIG. 7 illustrates a method of installing a box culvert.

At step S102, box culvert having sealed holes in a base panel (such as the box culvert 500 shown in FIG. 2) is provided. The sealed holes may be sealed using removable plugs, knockout panels, a combination thereof, or by other sealing means. Sealed holes may have different sizes, positions, and angles, and may be cast into a base panel of the box culvert.

At step S104, based on a determination for the installation site, at least one hole to unseal is selected. The determination to identify the at least one hole to unseal may be based on water depth, water speed, water temperature, nature presence, ground hardness, and hydraulic pressure measured at the installation site. Measurements may be taken at multiple points along an installation site. Based on these measurements, sealed holes (having a size, position, or angle) may be identified or selected. The selection may be further based on the available holes.

It will be appreciated that in some embodiments, the determination to identify at least one hole to unseal may be based on an installation site mapping. Installation site mapping may be generated based on a hydrogeology report describing the installation site, GPS measurements collected at installation site, and the physical characteristics of box culvert, according to one of the embodiments described above. For example, installation site mapping software may be used to automatically determine at least one hole to unseal.

At step S106, the at least one hole is unsealed. The at least one hole may be unsealed by pushing out a plug, pulling out a plug, drilling out a plug or knock-out panel, hammering out a knock-out panel, or any other means. The plugs may be removed at a location close to the installation site. Alternatively, plugs may be removed at an offsite location.

At step S108, the box culvert may be installed at the installation site. According to some implementations, the box culvert may be installed by lifting the culvert from a nearby location with a crane or other means, then placing the culvert in the waterway.

After installation, culvert may include a clear stone bedding or substrate below the culvert having a suitable depth (generally 0.3 m) and porosity to convey groundwater flow. Sections of the culvert may be properly sealed, an inlet cut-off wall may include one or more openings and be properly backfilled, and an outlet cut-off wall may be sealed. For example, the last section of culvert may be properly sealed with cohesive materials to allow flow through the clear stone gravel pack and into the sized openings in the base panel of the culvert. The typical specified streambed material is granular (sand, gravel and cobble) and allows movement of groundwater from the openings in the base panel, through the streambed material and into the stream, providing improvements to the aquatic conditions.

FIG. 8 illustrates a cross-sectional view of a box culvert 800 installed into stream bed 804. Box culvert 800 includes top panel 820 and base panel 810. Base panel 810 includes both sealed holes 812 and unsealed holes 816. Base panel 810 also includes inlet cut-off wall 830a and outlet cut-off wall 830b. In addition to seal holes 812 and unsealed holes 816 in base panel 810, inlet cut-off wall 830a may further include opening 832. Passage 862 is formed between top panel 820 and base panel 810, allowing stream water 860 to flow into box culvert 800. Stream flows in downstream direction 814.

Granular substrate 880a may be layered on the stream bed 804 below base panel 810 of box culvert 800. Similarly, granular substrate 880b may be layered onto the surface of base panel 810. The thickness of granular substrate 880a below base panel 810 may depend on depth of installation H of box culvert 800 and the height of base panel 810 from stream bed 804. The thickness of granular substrate 880b on top of base panel 810 may be chosen to match the height of the bottom of stream 860, such that the depth of stream 860 within and outside of passage 862 is the same. In some embodiments, one or both of granular substrate 880a and 880b may be clear stone bedding.

It will be appreciated that inlet and outlet cut-off walls 830a and 830b may extend deeper into stream bed 804 than does granular substrate 880a, such as to provide additional structural support to box culvert 800. For example, cut-off walls 830a and 830b may extend up to 1 m deep into stream bed 804, and may also be approximately 30 cm thick in the downstream direction 814. Cut-off walls 830a and 830b may also extend across the entire width of box culvert 800 in the direction transverse to downstream direction 814. In other embodiments, cut-off walls 830a and 830b may be installed at depths greater than 1 m and manufactured at greater or smaller thicknesses, depending on the physical characteristics of the installation site.

In some embodiments, the temperature and flow of groundwater input 834 into passage 862 may be controlled by depth of installation H of box culvert 800. Generally, the temperature of groundwater may be different than the temperature of stream water 860. For example, in colder climates, groundwater may be warmer than stream water 860, while in warmer climates groundwater may be colder than stream water 860.

As noted already, inlet cut-off wall 830a placed under inlet section of passage 862 may include opening 832. Opening 832 may include one or more openings, which may be perforations, channels, holes or other features that allow water to travel through inlet cut-off wall 830a. Opening 832 may be in the uppermost half of cut-off wall 830a to allow for groundwater input 834 to flow into the bedding below box culvert 800. The deeper cut-off wall 830a and its opening 832 are installed into the ground, the colder or warmer the temperature of groundwater input 834 into the granular substrate 880a may be. In some other embodiments, inlet cut-off wall 830a may include opening 832 in the lowermost half of cut-off wall 830a, or in both the uppermost and lowermost halves. The size or total area of opening 832 may be chosen such that the opening does not impede the flow of input groundwater 834 through inlet cut-off wall 830a.

Groundwater may enter granular substrate 880a transversely to downstream direction 814. For example, the native soil of stream bed 804 may be saturated with water. However, in addition to this groundwater traveling transversely to downstream direction 814, some stream water 860 may flow underneath the upper surface of stream bed 804 in downstream direction 814. Opening 832 in inlet cut-off wall 830a may ensure that this groundwater travelling in downstream direction 814 can enter granular substrate 880a beneath base panel 810 and eventually travel through unsealed holes 816 into passage 862 of box culvert 800. In particular, groundwater input 834 may flow through opening 832 in inlet cut-off wall 830a and into granular substrate 880a. Since outlet cut-off wall 830b may not include any openings, groundwater may not exit from below base panel 810 through outlet cut-off wall 830b. Instead, groundwater may only exit through stream bed 804 or unsealed holes 816. It will be appreciated that by providing a sufficient number of unsealed holes 816 in base panel 810, most groundwater may exit through unsealed holes 816 and into granular substrate 880b above base panel 810. This groundwater may eventually flow upward into passage 862 of box culvert 800 and mix with stream 860.

Technician or mapping software may determine the number and size of unsealed holes 816 based on the difference in temperature between the groundwater and the stream, as well as the relative flow rates between groundwater input 834, groundwater 804 and stream 860. For example, flow rate may be represented by Darcy's Law, as follows:

Q=−KAΔP  (Equation 1)

where K is the hydraulic conductivity, A is the cross-sectional area through which the flow is being assessed, and ΔP is the driving force/difference in pressure.

Equation 1 may be used to estimate the flow through several surfaces. Water flows from an undisturbed point upstream of box culvert 800. Water flows from the native soil of stream bed 804, through the upstream wall of box culvert 800, granular substrate 880a and 880b, downstream wall of box culvert 800, downstream gravel, and downstream native soil. While in granular substrate 880a, there may be additional flow from the native soil of stream bed 804 on the sides and bottom of the granular substrate 880a and through the top of granular substrate 880a into the interior of the box culvert 800 through unsealed holes 816.

Equation 1 may be used to estimate the flow through each of these planes. However, the number of equations may be minimized based on the following observations. For example, in the area upstream of box culvert 800 at the interface between the native soil of stream bed 804 and granular substrate 880a of the inlet cut-off wall, two equations may be considered: the equation for water leaving the native soil of stream bed 804 and the equation for water travelling through the granular substrate 880b. The hydraulic conductivity of the clear stone in granular substrate 880a may be much higher than the hydraulic conductivity of the native soil of stream bed 804, so the flow through the clear stone gravel pack may be limited by the flow out of the native soil. This same limited flow may pass through inlet cut-off wall 830a, and in particular through opening 832, and into granular substrate 880a. Consequently, it may be assumed that the flow of water travelling through the granular substrate 830a will be equal to the flow of water leaving the native soil of stream bed 804, such that the number of equations may be reduced to only one, namely the equation describing the flow leaving the native soil of stream bed 804. It is assumed that the gravel upstream of inlet cut-off wall 830a may be confined by a much less permeable material typical of the bottom of the stream.

On the downstream end of box culvert 800, the outlet cut-off wall 880b may be impermeable, such that there will not be any flow through outlet cut-off wall 830b. Similarly, outlet cut-off wall 880b may be properly sealed to ensure that no water can enter through the connection point between cut-off wall 880b and base panel 810.

All the water flowing into granular substrate 880a may come from native soil of stream bed 804. This water will flow through unsealed holes 816 in base panel 810 and into the streambed 860. The flow of water into granular substrate 880a is equal to the sum of the flows from the surrounding ground, namely the stream bed 804:

Q _GP =Q _g +Q _h  (Equation 2)

where Q_GP is the flow of water from the granular substrate into the stream 860, Q_g is the flow of water from the surrounding ground into granular substrate 880a and Q_h is the flow of water from upstream into granular substrate 880a through opening 832.

Substituting Equation 2 into Equation 1 produces:

Q _GP=(−K_gA_gΔP_g)+(−K_hA_hΔP_h)  (Equation 3)

where K_g is the hydraulic conductivity of the ground around box culvert 800, A_g is the area of ground below and to either side of box culvert 800 (not upstream or downstream), ΔP_g is the ground hydraulic pressure or driving force pushing water from ground into granular substrate 880a, K_h is the hydraulic conductivity of the ground upstream (hyporheic zone) of box culvert 800, A_h is the area of gravel upstream of inlet cut-off wall 830a of box culvert 800, and ΔP_h is the hyporheic hydraulic pressure pushing water from hyporheic zone through opening 832 of inlet cut-off wall 830a into granular substrate 880a.

If the hydraulic conductivity of the native soil is uniform throughout the installation, the hydraulic conductivity of the native soil of stream bed 804 beside and below granular substrate 880a may be the same (K_g=K_h). As well, if the hydraulic pressure of the native soil is uniform throughout the installation, the hydraulic pressure of the soil of stream bed 804 beside and below the granular substrate 880a may be the same (ΔP_g=ΔP_h). Equation 3 can thus be simplified, as follows:

Q _GP =−K _g(A_g+A_h)ΔP_g  (Equation 4)

Since the areas A_g and A_h are known, the only remaining unknowns are K_g and ΔP_g. However, K_g can be estimated from the soil type of the surrounding soil and ΔP_g may be measured prior to the design of box culvert 800 for a given location. As such, Equation 4 can be used to calculate Q_GP.

Once Q_GP is calculated, the number and size of unsealed holes 816 may be determined based on the difference in temperature between the groundwater and the stream, as well as the relative flow rates between the groundwater and the stream. The number of unsealed holes 816 may provide sufficient discharge zones to maximize the number of spawning locations for desired aquatic wildlife. If Q_GP is equal to the flow of the stream, then many sealed holes 812 may be unsealed in box culvert 800. However, Q_GP is typically much smaller than the flow of the stream, so the number of holes may be limited.

As noted already, since Q_GP may be determined by the hydraulic conductivity of the surrounding ground and the flow of the stream may be related to the slope of the land, it may be expected that Q_GP will be much less than the flow of the stream. For example, if it is assumed that Q_GP is 1% of the flow of the stream, and it is assumed that there is a single unsealed hole 816 in base panel 810 of box culvert 800 and a stream flow rate of 100 L/min, then Q_GP will be 1 L/min. As the water flows up through the bottom of box culvert 800, the water temperature may match the groundwater temperature because it will not have had any opportunity to mix with the stream water. As this water gets close to the surface of the stream, both waters will mix and create a separate temperature pool. The resulting temperature difference could be insignificant or greatly increase, depending on the relative temperatures between the groundwater and the stream water. This temperature difference is critical in creating a localized environment that supports spawning and the sustainability of aquatic life. If it is assumed that the stream temperature is 15° C. and the groundwater temperature is 10° C., the stream temperature just downstream from where the groundwater enters will be 100 L/min×15° C.+1 L/min×10° C./101 L/min=14.95° C., which may be undetectable. However, if the entry point is a depression in the stream bottom and it is protected by a big rock or loose gravel, then the temperature could be closer to the ground water temperature.

It will be appreciated the number of unsealed holes 816 may be related to the calculated flow and the flow rate of the stream through box culvert 800. The number and size of unsealed holes 816 may be determined based on the calculations described above. Alternatively, other calculations may be used to determine the number and size of unsealed holes 816.

In some further embodiments, the number and size of unsealed holes 816 may also be determined based on the velocity required to keep sand and fines from settling on base panel 810, since some desired aquatic species do not like a mucky bottom. The total size of unsealed holes 816 may be chosen such that the total velocity of groundwater coming up through unsealed holes 816 is high enough to keep sand from settling around unsealed holes 816. For example, if the velocity of water passing through unsealed holes 816 is higher than the terminal velocity for a particle, then the particle cannot settle in the flow. It will be appreciated that a smaller total area of unsealed holes 816 may result in a higher velocity for groundwater particles, thus preventing sand and fines from settling in the unsealed holes 816. This velocity may further prevent the settling of sand and fines in selected areas on base panel 810, providing areas clear of a mucky bottom.

Although the present invention has been described with reference to specific features and embodiments thereof, various modifications and combinations can be made thereto without departing from the invention. The description and drawings are, accordingly, to be regarded simply as an illustration of some embodiments of the invention as defined by the appended claims, and are contemplated to cover any and all modifications, variations, combinations or equivalents that fall within the scope of the present invention. Therefore, although the present invention and its advantages have been described in detail, various changes, substitutions, and alterations can be made herein without departing from the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed, that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.

Claims

1. A box culvert, comprising: a top panel;a base panel; anda first and second side panel extending from the top panel to the bottom panel;

2. The box culvert of claim 1, wherein the sealed holes each comprise a plug.

3. The box culvert of claim 1, wherein the sealed hole is a knockout panel.

4. The box culvert of claim 2, wherein the sealed holes each further comprise a sealant configured to hold the plug in the hole.

5. The box culvert of claim 4, wherein the sealant is a wax or a caulk.

6. The box culvert of claim 2, wherein the plug is integrally formed in the box culvert.

7. The box culvert of claim 2, wherein the plug is made of a different material than the box culvert.

8. The box culvert of claim 1, wherein the sealed holes are a through holes extending perpendicularly from a first plane to a second plane of the base panel.

9. The box culvert of claim 1, wherein the sealed holes are angled.

10. The box culvert of claim 1, wherein the box culvert is concrete.

11. The box culvert of claim 1, wherein the base panel has an inlet cut-off wall extending across an input end of the base panel and an outlet cut-off wall extending across an output end of the base panel.

12. The box culvert of claim 11, wherein the inlet cut-off wall includes one or more openings for groundwater to pass through the inlet cut-off wall and the outlet cut-off wall is configured to be impermeable.

13. A method of installing a box culvert, comprising: providing a box culvert having sealed holes in a base panel;selecting, based on a determination for an installation site, at least one sealed hole to be opened;opening the seal of the selected at least one sealed hole to be opened; andinstalling the box culvert.

14. The method of claim 13, wherein the sealed holes are sealed using plugs.

15. The method of claim 13, wherein the sealed holes are sealed using knockout panels.

16. The method of claim 13, wherein the determination is based on at least one of the water depth, the water speed and the water temperature at at least one location in the installation site.

17. The method of claim 13, wherein the determination is based on at least one of the diameters of the sealed holes, the angles of the sealed holes, the position of the sealed holes and a desired velocity of water particles to prevent sand from settling on the base panel.

18. The method of claim 14, wherein the opening the seal comprises removing the plug.

19. The method of claim 14, wherein the opening the seal comprises removing the knockout panel.

20. The method of claim 14, wherein the sealed holes are angled.