Jiulong River Trunk Sewer Collapse Rehabilitation Project

Pipe collapse remains one of the most challenging issues in the trenchless rehabilitation industry. These incidents are often sudden, affect extensive areas, and are difficult and costly to address using traditional open-cut methods.

Complicated geological conditions, pipe aging, and construction challenges further increase the complexity of such projects. Leveraging advanced technology and efficient project management, the Anyue team successfully delivered the Jiulong River trunk sewer rehabilitation project, overcoming numerous technical obstacles.

1. Project Background and Challenges

Current Situation

The Jiulong River trunk sewer had remained unused for an extended period after construction. Its proximity to the river resulted in sections experiencing collapse and rupture, posing significant safety risks.

Construction Challenges

• The sewer suffered from internal collapse and high groundwater levels, which made conventional excavation extremely challenging.

• Land acquisition for traditional repairs was difficult, resulting in long project timelines, high costs, and increased risk of secondary collapses.

• The rehabilitation spanned 2.4 kilometers, traversing farmlands, orchards, and private roads—areas with complex environments that hindered access for heavy machinery.

Client Requirements

The client required completion within a strict timeframe, restoration of flow capacity, and rigorous assurance of both construction quality and long-term operational safety.

2. Anyue’s Three-Step Systematic Solution

Precise Diagnostics—“CT-Grade” Fault Identification

• Utilized high-resolution CCTV inspection technology to thoroughly assess the extent and severity of collapses and damage.

• Accurately identified and located joint dislocations and complete local collapses, providing a scientific basis for subsequent repair strategies.

Scientific Technology Selection and Structural Reinforcement—"Rebuilding the Framework"

• For areas with geological deficiencies, applied localized “Supac” grout injection techniques to rapidly stabilize the soil and enhance foundational integrity.

• Restored collapsed pipe sections and reinforced them internally using steel ring liners, significantly increasing structural strength and durability.

Segmental UV Cured-In-Place Pipe (CIPP) Rehabilitation—Comprehensive Structural Upgrade

• Employed UV CIPP technology to install seamless liners throughout the pipeline, dramatically improving overall strength and corrosion resistance.

• Compared to traditional methods, this approach reduced construction time by 60% and overall costs by 35%, greatly improving project efficiency.

3. Construction Highlights and Technical Advantages

Efficient Workflow

Implemented a “spot-to-line” rehabilitation approach: prioritized rapid pre-treatment of critical collapse points, followed by comprehensive inner wall reinforcement, ensuring synergy between local repairs and the overall system.

Specialized Grouting Materials

Deployed high-performance “Supac” soil solidifying agents to guarantee construction safety and minimize the risk of secondary collapse.

Advanced Lining Technology

UV-cured liner materials deliver high strength, excellent density, and outstanding corrosion resistance, significantly improving the pipe's operational safety and service life.

4. Rehabilitation Outcomes and Comparative Analysis

Post-rehabilitation inspections confirmed that the pipeline’s internal wall friction coefficient and flow capacity met or exceeded original design standards (compared to corrugated pipes).

Structural pressure resistance was significantly enhanced, ensuring safe and reliable long-term operation and providing a robust foundation for network stability.