Damn bridge repair: Nuflow’s gravity-defying solution

Damn bridge repair: Nuflow’s gravity-defying solution

Project overview: Callide Dam flood control structures

Callide Dam, located in Biloela, Queensland, serves multiple purposes including irrigation for agricultural industries. Callide also features a series of dam bridges that function as flood control structures, utilising a counterweight system for operation. Reinforced cement pipes, containing concrete REO bars, pump water into large chambers to lift the bridges and release water when levels become critical.

During a routine dam maintenance inspection, the local water authority identified a malfunction in one of the dam bridges – it would open momentarily before closing abruptly. A dye test confirmed water leakage from the cement pipes, necessitating urgent bridge repair as part of the dam’s maintenance program.

However, the challenge lay in the pipes’ location. They were encased in 600m of concrete within the footing walls, making traditional replacement methods unfeasible without significant structural damage. But with Nuflow’s skills and solutions, this could be overcome. 

Technical challenges and innovative solutions

Upon inspection, the Nuflow Central Queensland team, led by franchise owner Ben, identified several unique challenges. CCTV technology revealed the concrete pipes were shaped like a horseshoe, extending 17m vertically on either side before bending to span 14m horizontally at the bottom. This configuration meant that the majority of the relining needed to occur vertically, requiring a departure from standard horizontal relining techniques.

Furthermore, traditional pipe cleaning methods using vacuum and water jetting proved ineffective. This was due to fragmented steel from the reinforced pipes and high head pressure (170kPa) in the vertical sections. Their vacuuming equipment was not strong enough to remove the steel from the pipe, so the team had to devise an innovative solution to address this issue.

In response, the team developed a custom magnetic cleaning method. They used 100mm round, high-strength magnets to remove the metal fragments from the pipes. This process, while time-consuming, proved highly effective in preparing the pipes and ensuring proper adhesion of the new lining.

Product specifications and execution

After careful analysis of the head pressure and pipe conditions, the team selected Nuflow Standard Liner with Blueline Underwater Resin for optimal performance in this high-pressure environment. This choice of materials was crucial to ensure the longevity and effectiveness of the concrete repair.

preparing for the dam bridge repair
preparing for the dam bridge repair
Preparing the liner and resin.

For the relining process itself, the team employed a strategic liner insertion method. Instead of relining from end to end, they inserted the liner at an access point above the bend and halfway down the bottom pipe. This approach allowed for easier manipulation and installation of the liner. For the vertical sections, the liner was suspended and inflated in place for curing, adapting their techniques to the unique demands of the project.

suspended liners for dam bridge repair
The liners suspected down the vertical pipes.

The project was completed over a four-day period. The first day was dedicated to the custom magnetic cleaning process, meticulously removing metal fragments from the pipes. The second day saw a weather delay, but the team used this time effectively to secure the site and prevent water infiltration into the cleared pipes. The final two days were spent on lining installation and curing, bringing the project to a successful conclusion.

Results: a happy client and safer infrastructure 

The successful completion of this project resulted in the full restoration of bridge functionality without any structural damage to the existing infrastructure. This not only solved the immediate issue but also enhanced the long-term reliability of the flood control system. 

The water authority expressed high satisfaction with the results and the professional approach of the Nuflow team. This positive outcome has led to discussions about potential future projects on additional bridges at the site.

Trust Nuflow with your infrastructure maintenance  

Nuflow’s innovative approach to the Callide Dam project showcases our ability to tackle complex pipe rehabilitation in critical infrastructure. By combining technical expertise with creative problem-solving, we delivered a solution that extended the lifespan of vital water management assets, ensuring their continued effectiveness and reliability.

This case study demonstrates how Nuflow can adapt standard trenchless rehabilitation techniques to unique infrastructure challenges, providing cost-effective solutions for complex water management systems. Our capacity to innovate and overcome obstacles positions us as a leader in the field of pipe rehabilitation and infrastructure maintenance.

For more information on how Nuflow can assist with your infrastructure maintenance needs, including dam bridge repair, concrete pipe rehabilitation, or other trenchless pipe repair projects, please contact our team of specialists. We stand ready to apply our expertise to your most challenging pipe rehabilitation projects, ensuring the longevity and efficiency of your critical infrastructure.

Latest news

Nuflow’s Training Shines a Light on UV Pipe Relining in New Zealand

Nuflow Australasia has taken a progressive step in advancing pipe relining solutions in New Zealand by

Australia’s UV Pipe Relining Revolution Fueled by Nuflow’s Cutting-Edge Training

Nuflow Australasia recently hosted an in-depth, multi-day training session at their head office in the Gold

Northland residents and businesses will now have access to innovative pipe re-lining solutions that change the game in pipe repair. Nuflow, New Zealand’s leading pipe relining company, is expanding its operations with a new franchise launching in the Northland region. This expansion brings their "pipe within a pipe" technology to address the area's aging infrastructure challenges. Zane Britton, owner of the newly established Nuflow Northland franchise, brings extensive industry experience and a vision for delivering advanced pipe rehabilitation solutions to the region. "After following Nuflow's developments through industry conferences and seeing their strong market presence, I was drawn to their comprehensive range of techniques and products," says Zane. "The technology offers superior solutions for Northland's unique challenges, particularly addressing years of poor installations that have left their mark on local infrastructure." The franchise will offer Nuflow's complete suite of pipe rehabilitation services, including their well-known and well-regarded trenchless technology that minimises disruption while maximising efficiency. This no-dig approach is particularly valuable for Northland's aging pipe network, offering a modern solution to traditional plumbing problems. Zane emphasises the practical benefits of Nuflow's technology for the region: "With the significant number of aging pipes in Northland, our technology provides a cost-effective solution with reduced health and safety risks. The niche market opportunities here align perfectly with Nuflow's capabilities." The new franchise aims to service all sectors in the region, from residential to commercial and industrial clients. "Every sector can benefit from these solutions," Zane notes, "our goal is to keep delivering quality results while also training new apprentices to support the industry's future." When asked about the support received from Nuflow, Zane praised the comprehensive training program: "The support and training have been excellent, providing us with everything needed to deliver these specialised services effectively." With Nuflow’s trusted materials and up to 50-year product warranty backing their services, Northland residents and businesses can now access state-of-the-art pipe relining solutions that promise to address their infrastructure needs efficiently and effectively. Looking ahead, Zane has clear objectives: "Our vision is to continue growing while maintaining high-quality service delivery and contributing to the industry's development through apprenticeship opportunities." As Nuflow Northland commences operations, local property owners and businesses can look forward to accessing innovative pipe rehabilitation solutions that offer an alternative to traditional repair methods, backed by proven technology and comprehensive support.

Northland residents and businesses will now have access to innovative pipe re-lining solutions that change the