culvert rehabilitation FAQ


What is the best way to slipline InfraSteel?

The lead piece of pipe may be tapered inward as necessary, with longitudinal cuts 3” to 4” long every 6 inches to facilitate the slip lining process. Also, tracks may be added to the bottom of the host pipe to facilitate the slip lining process. The InfraSteel liner is then pushed or pulled into place.

What is the best way to align the joints?

The bracing inside of the liner should be used as a visual tool to aid in alignment (think of aligning the crosshairs of a scope) when setting the piece into position. When welding one piece to another piece, for alignment, use the longitudinal weld seams in the haunches, where the bottom half is welded to the top half. There is also a mark at 12:00 and 6:00 center on each piece to aid in alignment.

Are there any tips I can give the welders?

Begin by tack welding the pipe, starting on the bottom, every 6 inches once it is aligned. The welders should begin at the bottom of the pipe, working upwards to the top. Porta Power machines, wedges, modified C-clamps and other tools may be required to manipulate the steel for alignment. Also, ears or tabs may be welded on the top of one piece so it can be hung on the next piece while it is being aligned.

How are the bevels configured?

The bottom of each piece has an inverted bevel so it can be welded from the inside. This allows for less excavation of the streambed and keeps the welder from having to work on his back under the pipe. However, we will provide other bevel configurations upon request.

What is the best way to grout?

We suggest grout ports be positioned every 10’ at 12:00 center. As grout is being pumped into the downstream end, the grout will fill up the annular space moving uphill. Grout ports may be installed at our plant or in the field, and should be specified at time of order. Grout tubes may also be used.

Will InfraSteel float when grouting?

Arched pipe with a flat bottom is more prone to float when grout is being pumped than pipe with a radius on the bottom. If necessary, prior to grouting, spacers may be added to keep the liner from floating by cutting a hole in the top of the liner and welding in a steel spacer that runs from the top of the liner to the ID of the host pipe structure.

What is the Manning’s Coefficient of InfraSteel?

.0120

Will InfraSteel rust?

The added copper in InfraSteel provides 2X the resistance to corrosion.

What about coatings?

Testing has proven that coatings are not effective for protecting culverts due to abrasion. Smooth wall steel plate outperformed all other products in destructive testing performed by Caltrans.

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