UV CIPP: DN1000 Sewage Pipeline Collapse Repair Project

1）Project Overview

The emergency repair project focused on the collapse of the DN1000 sewage pipeline upstream of the wastewater treatment plant. The pipeline, spanning 317 meters with a depth of 10.5 meters and a diameter of 1 meter, is a critical conduit for the city’s sewage flow. Due to its significant depth and the partial collapse of the sidewalk above, initial assessments pointed to pipeline deformation or rupture as the primary cause.

Traditional excavation and replacement methods would have been time-consuming, costly, and disruptive to the surrounding community and traffic. Instead, Anyue’s team opted for a trenchless repair solution, addressing the issue from within the pipeline to minimize environmental and social impact.

2）Key Challenges

1. Complex Geological Conditions: The pipeline’s depth of 10.5 meters, combined with unstable marine clay soil above, posed a high risk of secondary collapse during construction.

2. High Sewage Flow: The pipeline carries a substantial portion of the wastewater treatment plant’s inflow, making water diversion extremely challenging. Any misstep could disrupt the plant’s operations.

3. Multiple Pipeline Defects: The pipeline exhibited deformation, collapse, and cracking, requiring a tailored approach to address each issue effectively.

4. Harsh Working Environment: The confined space inside the pipeline, poor ventilation, and limited air supply demanded exceptional safety measures and operational efficiency.

Faced with these challenges, Anyue’s team leveraged their expertise and innovative solutions to deliver a successful repair, ensuring the city’s critical infrastructure remained intact.

3）Repair Strategy

After thorough inspection and cleaning, the pipeline was found to have significant defects, including deformation, collapse, and cracks. The repair was divided into two sections:

· Section 1: 15 meters of pre-treatment for collapse, followed by 155 meters of repair.

· Section 2: 20 meters of pre-treatment for collapse, followed by 162 meters of repair.

A．1. Pre-Treatment Measures

· Temporary Water Diversion: Given the high sewage flow, precise water diversion was critical. Anyue’s team implemented a meticulous diversion plan to ensure uninterrupted sewage flow and prevent operational disruptions at the treatment plant.

· Soil Stabilization via Grouting: For the deformed and collapsed sections, Anyue used Specchem AP600, a chemical grouting material, to stabilize the soil. This material rapidly bonds with the soil, forming a solid support structure to prevent further collapse.

· Steel Ring Lining Support: Post-grouting, high-strength steel ring linings were installed to provide structural reinforcement, ensuring the pipeline’s stability during repairs.

B．2. UV CIPP Lining Technology

Following pre-treatment, Anyue employed its UV CIPP liners for the pipeline repair. This advanced material offers exceptional corrosion resistance and high strength, forming a durable protective layer inside the pipeline. The repair not only restored structural integrity but also maintained the pipeline’s flow capacity.

C．3. Repair Outcomes

· Before Repair: The pipeline exhibited severe deformation, collapse, and cracks, with soil subsidence above posing a safety risk to the surrounding area.

· During Repair: Through precise water diversion, soil stabilization, steel ring support, and UV curing, the pipeline’s structural stability was gradually restored.

· After Repair: The pipeline regained its structural integrity, with a smooth, corrosion-resistant interior that maintained optimal flow capacity, eliminating the risk of future collapses.

D．4. New Manhole

To ensure long-term maintenance and safety, a new manhole was added midway along the 162-meter section.

Given the marine clay soil, a combination of wall protection and precast well sinking was used: the upper 6 meters utilized wall protection, while the lower 4.5 meters employed a 1.5-meter-diameter precast well, followed by the construction of the manhole.

4）Conclusion and Future Outlook

The successful repair of the DN1000 sewage pipeline collapse highlights Anyue’s technical expertise and innovative capabilities in trenchless pipeline rehabilitation. By tackling complex geological conditions, high sewage flow, and multiple pipeline defects, Anyue demonstrated its commitment to delivering efficient, reliable, and minimally disruptive solutions.

Central to this success was the use of Anyue’s advanced UV CIPP liner, which offers the following key advantages:

• Superior Structural Integrity: Ensures long-lasting performance even under high-pressure conditions.

• High Resistance: Excellent resistance to wear, corrosion, and permeation, extending the lifespan of rehabilitated pipelines.

• Radial Extensibility: Allows the liner to fit snugly with the original pipe, ensuring a seamless and secure repair.

• Smooth Interior Surface: Facilitates optimal fluid flow, reducing the risk of blockages and improving efficiency.

• Premium Materials: Made from AOC resin and alkali-resistant fiberglass, providing exceptional durability and UV light penetration for faster curing.

• Customizable Solutions: Tailored to meet the unique needs of each project, ensuring compatibility with a wide range of pipeline conditions.

This project underscores Anyue’s dedication to safeguarding critical urban infrastructure. Moving forward, Anyue will continue to uphold its principles of professionalism, innovation, and excellence, providing cutting-edge pipeline repair solutions that ensure the safety and sustainability of cities worldwide.

Why Choose Anyue? At Anyue, we combine advanced technology, extensive experience, and a customer-first approach to deliver solutions that exceed expectations. Our innovative trenchless repair methods minimize disruption, reduce costs, and extend the lifespan of critical infrastructure. Trust Anyue to protect your city’s lifelines—because when it comes to pipeline repair, we don’t just fix problems; we build resilience.

Contact Us Today to learn more about our services and how we can help you tackle your most challenging infrastructure projects.