Fhwa box culvert design software

The size and shape of a culvert not only determine the structure's effectiveness, especially during extreme weather events such as major floods and washouts, but they also significantly affect the overall construction costs of a project. Oversized culverts equate to higher costs than are necessary to do the job effectively, especially for construction materials such as concrete. State DOTs are interested in culvert hydraulics because they install a large number of culverts every year.

Based on Form FHWA data which catalogs materials and labor used by contractors on highway construction projects involving Federal funds , more than , meters 2.

That equates to roughly 7, kilometers 4, miles over a year period. Although this statistic includes all pipes, culverts represent a high percentage of the total in this size range. Further, this statistic does not include field-cast concrete culverts, but it does reflect the order of magnitude of culvert installations in the United States.

First published in , HDS-5 is based primarily on research that was sponsored by the Bureau of Public Roads the predecessor to FHWA in the late s and early s and industry-supported research conducted during the s. Since the initial publication of HDS-5, researchers, especially in the precast industry, have developed a number of alternative configurations for box culverts, which are usually square or rectangular reinforced concrete structures with single or multiple openings.

New culvert configurations and designs raise questions about the effectiveness of subtle differences or changes in the geometry or configuration of the inlet edges of the culvert. In South Dakota, as in other States, engineers have the option of using precast or cast-in-place concrete for box culverts. Precast inlets generally have straight zero-degree wingwalls, while field-cast inlets may feature straight or flared wingwalls.

In a straight inlet, the wingwalls extend straight out from the end of the barrel section. With a flared inlet, the wingwalls flare outward, creating a sort of funnel shape before the barrel section. According to Clausen, the current inlet coefficients used in computer models frequently specify larger openings for the precast options than needed, leading to oversized and conservative designs for straight inlets. The precast industry can produce a variety of edge treatments for culverts once the forms are fabricated.

Therefore, the first factor that the research team considered was the effect of streamlining the bevels on the top plate and wingwalls at the culvert entrance. The researchers expected to find that by streamlining the edges of straight wingwalls they could yield enough hydraulic gain to compare favorably with the hydraulic performance of flared wingwalls, which are common among cast-in-place installations in the field.

Other factors investigated in the study include corner fillets fabricated corners filled slightly to avoid concentrating stress in sharp turns , multiple barrels a culvert unit composed of two or more barrels adjacent to each other , extended inner walls, span-to-rise ratios, skewed crossings, submerged and unsubmerged inlets, and two different barrel slopes.

The factors were tested under a wide range of flow conditions to determine how they affect the design coefficients used to evaluate culvert performance for both outlet control and inlet control situations.

The design coefficients derived in this study were the entrance loss coefficients, which are the numbers multiplied by the velocity head to estimate the entrance energy loss for a culvert operating in outlet control where the headwater depth is influenced by tail water and friction in the culvert as well as the entrance loss. A lower entrance loss corresponds with a lower headwater at the upstream side of the highway embankment. The design coefficients are a set of regression coefficients relating headwater depth to discharge intensity for each inlet configuration for culverts operating in inlet control, where the headwater depth is influenced by the inlet geometry but not by friction in the culvert or the tail water.

Although engineers traditionally treated culverts with multiple barrels as a combination of single-barrel units, the research team sought to challenge the adequacy of that assumption. Intuitively, the researchers expected that a multiple-barrel installation might perform slightly better than a number of adjacent single-barrel culverts because the inner barrels do not have much flow contraction.

The inner walls of a multiple-barrel installation are usually flush with the headwall, but the researchers questioned whether there might be an advantage to extending the inner walls onto the approach apron, just as the wingwalls are extended.

By placing the two culverts side by side, the inner wall becomes thicker. He adds, "That practice leaves one double-thick inner wall, which is a detriment, but to what degree?

Further, because highway alignments are not always perpendicular to streams, culverts should be skewed to the highway embankment, as opposed to attempting to change the direction of the stream. Although the authors have observed a number of installations where the culvert did change the flow direction, the tests conducted in this study were limited to cases where the highway alignment and culvert wingwalls, but not the culvert barrel, were skewed to the flow direction.

Researchers conducted approximately tests at the TFHRC Hydraulics Laboratory, with the physical modeling for the culvert study occurring in two phases. The first set of experiments optimized the bevel edge of the wingwalls and top edge using two-dimensional particle image velocimetry PIV in a 2. This technology uses a laser and particles of silver-coated and hollow glass spheres to make the flow visible.

Cameras are used to measure instantaneous velocity vectors in a flow field. The researchers tested several bevel edge conditions, including straight top bevels square edge , beveled edge 45 degree bevel , and radius top bevels. The criterion they used to determine the best bevel performance was the contracted distance outside the viscous boundary layer, or the effective flow depth at the vena contracta where the flow depth is lowest inside the barrel section.

The researchers used integrated streamlines, which indicate the speed and direction of flow, to visualize the contracted area the area where water flow narrows from a wider flow inside the culvert. A second phase of experiments consisted of a culvert setup with a head box measuring 2.

Plexiglas was used because it has similar friction to that of concrete in the model scale, yet unlike concrete would enable researchers to view the behavior of the water flow. The inlet models were designed as modular clip-in parts wingwalls, center walls, and top plates that could be changed easily to test various configurations. Two sets of model fillets Electronic pressure sensors installed in the floors of the head and tail boxes measured the headwater and tail water depths.

The researchers installed as many as 40 pressure sensors in the culvert barrels to measure the hydraulic and energy grade lines that were necessary to compute loss coefficients.

An automated tailgate a gate that regulates water flow depth in the flume at the downstream end of the tail box helped maintain control of the tail water. The barrels were tested for two different slope settings. The steep slope 3 percent accounted for inlet control conditions. Methodologies and standards for calculation procedures have long been established.

We worked hard at making this software easy to use. Its intelligent user interface is immediately evident when you first begin entering data into Culvert Studio. It watches over your input progress and displays helpful, context-sensitive diagrams along the way to keep you moving, stress-free. It makes graphics rendering lightning fast. Program updates occur with a single mouse click.

Culvert Studio is a stand-alone software product. An internet connection is required for automatic program updates. Culvert Studio. Try It Today. This is Culvert Design Software What You Can Do With Culvert Studio Design and model single-barrel crossings or multi-barrel culverts with various shapes, inlet configurations, materials, slopes positive or negative , sizes and flow regimes including supercritical flow with hydraulic jumps and over-topping flow.

System Compatibility HY-8 is a bit program, and only compatible with bit Windows-based operating systems. HY-8 has been updated to improve compliance. The program can now be navigated with the keyboard with increased menu tools and navigation. Each dialog was reviewed for keyboard navigation.

The documentation has been updated to follow compliance by using formatting, style sets, and alternate text for images.

The report generator was updated to use style sets. Download Agreement By downloading the software, users acknowledge that they have read and agree to the following conditions: The application of this software is the responsibility of the user.

It is imperative that the responsible designer understands the potential accuracy limitations of the program results, independently cross checks those results with other methods, and examines the reasonableness of the results with engineering knowledge and experience. There are no expressed or implied warranties. I agree to these conditions when downloading the software. HY-8 Version 7. Updated the Quick Start Guide.