As part of its first ordinance in 2017, the Talty City Council in Talty, Texas, authorized funding for an expanded roadway improvement project. Bids for the project were opened to the public in February, and a bid was accepted within the month that allowed for construction to begin late February.
Located on Interstate 20 twenty miles east of Dallas, Talty is ideally suited to those seeking large residential lots within easy commuting distance to the urban center, and as such the city is constantly assessing road condition in order to incorporate new improvements and ongoing city road projects and expansions.
Project enhancements included significant drainage improvements designed to better protect residential properties from rising water during heavy rains along Layden’s Ridge Drive, Michael Talty Avenue and Cleaver Lane. The roadway enhancements included new asphalt paving and resurfacing the existing roadways, the construction of a new concrete cul-de-sac, as well as additional culverts and ditch grading to help with the improvement of drainage to the area.
“Getting our road improvements under way has been a major goal, explained Mayor Larry Farthing during a Jan. 25 council meeting, per inForney.com. â€œWe appreciate the patience of our citizens and efforts of our team. Weâ€™re happy to provide the much-needed relief from road and drainage problems. And getting past the implementation stage will allow us to begin shifting focus to other important issues.”
Along Layden’s Ridge Drive (CR 213), an existing culvert was severely deteriorated and the City determined it was in need of repair and/or replacement. BGE Inc., the engineer of record for the Talty roadway improvement project, reached out to a company that had been involved with relining drainage structures since the 1930s, Contech Engineered Solutions, to identify possible solutions. Having had previous experience with Contech, BGE was confident that the right solution would be available given the wide variety of materials and pipe types manufactured by Contech.
The two-lane road was not a major arterial road. However, given the nearby location of a private residential subdivision, it was critical that the road be kept open for the local residents. Considering this aspect of the project, BGE Inc. looked into the possibility of relining the existing culvert. Rehabilitation and relining a drainage structure can be complicated and requires a site-specific analysis process. There is no one-size-fits-all approach. Every reline project should be examined closely by qualified professionals. Upon consultation with Contech, BGE Inc. selected Aluminized Steel Type 2 (ALT2) ULTRA FLO spiral rib pipe due to its hydraulic efficiency and minimum 75-year service life.
The unique profile of the spiral rib pipe would provide a smooth interior improving the hydraulic capacity capable of a Manning’s “n” of 0.012, equivalent to that of concrete pipe, while the exterior box ribs provide the structural strength. Adding to these inherent benefits, ULTRA FLO is also one of the most economical pipe reline solutions.
Upon the decision to proceed with use of spiral rib pipe, the local Contech manufacturing facility manufactured the pipe that was needed, and it was quickly delivered to the site location. The installation of the spiral rib pipe, diameters ranging from 48 to 96 in., was performed by Chiener Construction LLC in accordance with AASHTO Standard Specifications for Highway Bridges, LRFD Section 26 and conformed to the project plans and specifications. The pipe included manufactured grout ports and caps to simplify the grouting process. Once the new liner pipe was delivered directly to the site, the installation was performed by the local contractor who utilized a simple block and bracing method along skid rails to push the liner pipe directly into the host pipe prior to grouting.
Grouting was an important part of the relining process. It fixes the position of the new liner pipe, provides uniform support, and inhibits further failure of the host pipe. The grouting process involves intermittent dispensing of fluid materials that must pass through 2-in. hoses and fittings. As a result, high slump, low strength grout mix that contains fly ash or plasticizer additive helps ensure that all voids are filled. Performed in multiple stages, this approach allowed for a large reduction in effective buoyant force due to fluid grout. A 28-day compressive strength of 150 psi was maintained, per the project specifications. This technique required a well thought out bracing and blocking scheme all while a full evaluation of shape control and grout fluidity is conducted, pumping rate and pressure was maintained to ensure proper placement of the liner pipe into the host.
Once the grout was properly set, the new spiral rib liner pipe was able to provide a fully structural solution extending the life of the existing culvert for 75 years minimum. The decision to reline the failing culvert saved the city a significant amount of time and money while also keeping disturbance to the surrounding community to a minimum.
“Contech’s ULTRA FLO pipe provided an opportunity to slipline a smaller diameter, more hydraulically efficient pipe within a larger pipe while maintaining the existing flows,” said BGE Inc. project manager Michael Smith, P.E. “In addition, the roadway closure is minimized, and this aspect is critical as there is not an economically feasible bypass and Michael Talty Avenue and Cleaver Lane are dead-end roads. The Contech team visited the site during construction and provided insight to the contractor which helped streamline the pipe placement.”
When the opportunity arises, the ability to slipline provides numerous benefits. There is minimal disturbance to the surrounding area which helps to reduce disturbance to the environment as the site footprint is much smaller. With little digging required, the time involved in the rehabilitation of the site is severely reduced, which also saves both time and cost.