Los Angeles Sewer Pipeline Rehabilitation Projects

1. Project Overview and Background

The City of Los Angeles manages an extensive wastewater collection system that includes approximately 6,700 miles (10,782 kilometers) of sewer pipelines, ranging in diameter from 6 inches to 150 inches (15 cm to 3.8 meters). A significant portion of this infrastructure was constructed in the early 20th century, with many of the larger-diameter pipes built using unreinforced concrete with clay brick or tile linings (3). Approximately 64 miles (103 kilometers) of these pipelines feature non-circular designs, including elliptical, semi-circular, and horseshoe-shaped configurations (3).

The aging nature of Los Angeles' sewer system presents significant challenges, including:

  1. Structural deterioration: Many pipes are nearing or have exceeded their 100-year service life, resulting in reduced structural integrity (3)
  2. Corrosion issues: Aggressive hydrogen sulfide corrosion has caused severe wall thickness loss in many concrete pipes, with some areas experiencing over 75% material loss (21)
  3. Non-circular geometry: The prevalence of non-standard pipe shapes complicates traditional repair approaches (3)
  4. Urban constraints: The majority of the sewer system is located beneath heavily trafficked roads and densely populated areas, making conventional excavation-based repairs disruptive and costly (3)

To address these challenges, the City of Los Angeles has implemented an aggressive sewer pipeline rehabilitation program focused on trenchless technologies. These methods minimize disruption to traffic and daily activities while providing cost-effective solutions for extending the service life of aging infrastructure .

1.1 Current Rehabilitation Strategy

The Los Angeles Bureau of Engineering has adopted a comprehensive approach to sewer rehabilitation that emphasizes:

  1. Structural assessment: Utilizing advanced inspection technologies including high-resolution closed-circuit television (CCTV), sonar monitoring, and laser profiling to accurately evaluate pipe conditions (20)
  2. Risk-based prioritization: Focusing rehabilitation efforts on pipes with the highest risk of failure and greatest consequence if they were to fail (20)
  3. Trenchless technology application: Implementing a variety of trenchless rehabilitation methods suitable for different pipe conditions, sizes, and locations
  4. Sustainable materials: Using modern, corrosion-resistant materials that provide extended service life with minimal maintenance requirements (20)

To date, Los Angeles has successfully rehabilitated or replaced over 100,000 feet (30,500 meters) of sewer pipelines using trenchless methods . This document provides a detailed technical overview of the primary trenchless rehabilitation technologies employed in Los Angeles, along with case studies demonstrating their application and performance.

2. Key Trenchless Rehabilitation Technologies

2.1 Cured-in-Place Pipe (CIPP) Lining

Cured-in-Place Pipe (CIPP) lining is one of the most widely used trenchless rehabilitation methods in Los Angeles, particularly for structural repairs and long-distance pipeline rehabilitation (12).

Technology Description

CIPP involves inserting a resin-impregnated liner into the existing pipeline, which is then expanded to conform to the host pipe's inner surface and cured in place. The result is a structurally independent, corrosion-resistant new pipe within the existing one .

The CIPP process typically involves the following steps:

  1. Pre-inspection: The existing pipe is thoroughly inspected using CCTV to identify defects and ensure it is suitable for CIPP rehabilitation (15)
  2. Cleaning: The pipe is cleaned of debris, roots, and other obstructions to prepare for liner installation (15)
  3. Liner preparation: A felt or glass fiber fabric tube is impregnated with a thermosetting resin (typically polyester, vinyl ester, or epoxy)
  4. Installation: The resin-impregnated liner is inserted into the host pipe using either inversion (pushed by water or air pressure) or pull-in-place methods (41)
  5. Inflation: The liner is expanded against the host pipe wall using air pressure, water pressure, or a combination of both
  6. Curing: The resin is cured using one of several methods:
    • Hot water/steam curing: Recirculating hot water or steam at temperatures up to 180°F (82°C) for 3-6 hours
    • UV curing: Exposure to ultraviolet light, which can cure the resin in as little as 1-2 hours
    • Ambient curing: Allowing the resin to cure at normal environmental temperatures, which takes significantly longer but may be necessary in sensitive environments
  7. Post-inspection: After curing, the new liner is inspected using CCTV to verify installation quality and ensure all service connections are properly reinstated (15)

Material Selection

The choice of resin material depends on several factors, including:

  • Pipe diameter: Larger pipes may require stronger materials
  • Expected service conditions: Corrosive environments may necessitate more resistant resins
  • Curing method: Different resins cure optimally under different temperature conditions
  • Cost considerations: Epoxy resins generally provide superior performance but come at a higher cost than polyester alternatives

In Los Angeles, the most commonly used CIPP materials include:

  • Polyester resin: Economical choice suitable for most gravity sewer applications
  • Vinyl ester resin: Provides enhanced chemical resistance for corrosive environments
  • Epoxy resin: Offers the highest strength and chemical resistance but at a premium cost

Advantages of CIPP

CIPP offers numerous advantages that have made it a preferred rehabilitation method in Los Angeles:

  1. Seamless lining: Creates a continuous, watertight liner without joints, eliminating potential leak points
  2. Full structural capacity: When properly designed, CIPP liners can provide a complete structural solution, effectively creating a new pipe within the old one
  3. Excellent hydraulic performance: The smooth interior surface of CIPP liners improves flow capacity and reduces the likelihood of future blockages (24)
  4. Minimal excavation: Requires only access points at manholes or other existing structures (15)
  5. Adaptability: Can be used in pipes of various shapes (including non-circular) and sizes from 4" to 96" (10 cm to 244 cm)
  6. Long service life: Properly installed CIPP liners can provide 50-100 years of service life with minimal maintenance requirements

Case Study: Normandie Sewer Rehabilitation Project

The Normandie Sewer Rehabilitation Project represents a significant application of CIPP technology in Los Angeles. Completed in the mid-2010s, this project involved rehabilitating a 1915-vintage sewer line that served an area of approximately 22 square miles, primarily occupied by commercial and light industrial businesses (12).

Project Challenges:

  • The sewer was located in a heavy traffic area, making traditional excavation-based repair methods highly disruptive
  • Previous assessments indicated severe deterioration requiring structural repair
  • The project needed to maintain service to the area during rehabilitation (12)

Solution Approach:

  • UV-cured CIPP was selected as the preferred rehabilitation method due to its minimal traffic impact and ability to provide full structural support
  • The project involved extensive pipe cleaning and preparation to ensure proper liner adhesion
  • The CIPP liner was designed to provide a 50+ year service life with improved hydraulic capacity (12)

Project Execution:

  1. The existing sewer was thoroughly cleaned and inspected using CCTV to identify all defects
  2. A polyester resin-impregnated felt liner was pulled into place through existing manholes
  3. The liner was inflated using air pressure to conform to the host pipe
  4. UV curing was used to rapidly cure the resin, significantly reducing project duration compared to traditional hot water curing methods
  5. Service connections were robotically reinstated after curing (12)

Project Outcomes:

  • The project was completed with minimal disruption to traffic and surrounding businesses
  • The rehabilitated sewer now provides improved hydraulic capacity and structural integrity
  • The UV curing process reduced project time by approximately 50% compared to traditional methods
  • The rehabilitated sewer is expected to provide 50+ years of reliable service (12)

2.2 Slip Lining

Slip lining is another key trenchless rehabilitation method employed in Los Angeles, particularly suitable for pipelines where structural integrity is compromised but not completely lost (9).

Technology Description

Slip lining involves inserting a new pipe (the "slip liner") into the existing host pipe through small access pits. The annular space between the slip liner and host pipe is typically grouted to stabilize the system and prevent groundwater infiltration (22).

The slip lining process typically involves the following steps:

  1. Pre-inspection and preparation: The existing pipe is inspected to determine its condition and suitability for slip lining. The pipe is then cleaned and any obstructions are removed (9)
  2. Access pit construction: Small access pits are excavated at the beginning and end of the rehabilitation section (9)
  3. Slip liner preparation: The new pipe (typically HDPE or GRP) is prepared for insertion. Joints are preassembled where possible to minimize work inside the pipe (22)
  4. Insertion: The slip liner is pulled or pushed into the host pipe. Specialized equipment such as winches or hydraulic jacks may be used for this purpose (9)
  5. Grouting: The annular space between the slip liner and host pipe is filled with grout to provide structural stability and prevent groundwater infiltration (22)
  6. Service reinstatement: Connections to the new slip liner are established, typically through small access points or by excavating and reconnecting at manholes (9)
  7. Final inspection: The completed installation is inspected to ensure proper alignment and functionality (9)

Material Selection

The choice of slip liner material depends on several factors, including:

  • Pipe size and configuration: Larger diameters may require stronger materials
  • Expected service conditions: Corrosive environments may necessitate more resistant materials
  • Installation method: Some materials are better suited for pushing versus pulling installation methods
  • Cost considerations: Different materials offer different cost-performance tradeoffs (22)

In Los Angeles, the most commonly used slip lining materials include:

  • High-Density Polyethylene (HDPE): Lightweight, flexible, and corrosion-resistant, making it suitable for a wide range of applications
  • Glass Reinforced Polymer (GRP): Provides high strength and stiffness, ideal for larger diameter pipes or where higher structural capacity is required
  • Polyvinyl Chloride (PVC): Economical choice with good chemical resistance properties (22)

Advantages of Slip Lining

Slip lining offers several advantages that make it a valuable rehabilitation option in Los Angeles:

  1. Structural reinforcement: Provides additional structural support to the existing pipe, extending its service life
  2. Minimal excavation: Requires only small access pits rather than continuous trenching
  3. Wide material options: Can utilize a variety of materials tailored to specific project requirements
  4. Good flow characteristics: Smooth interior surfaces maintain or improve hydraulic capacity
  5. Adaptability: Can be used in pipes with some ovality or deformation, provided they are not completely collapsed
  6. Long service life: With proper material selection and installation, slip lining can provide 50+ years of service life

Case Study: La Cienega Interceptor Sewer Rehabilitation Project

The La Cienega Interceptor Sewer Rehabilitation Project represents a significant application of slip lining technology in Los Angeles. This project involved rehabilitating 11,500 feet (3,505 meters) of sewer pipeline with nominal diameters of 39", 42", and 63" (99 cm, 107 cm, and 160 cm) (9).

Project Challenges:

  • The sewer was located in a heavily urbanized area with significant traffic impacts if traditional excavation methods were used
  • The project involved multiple pipe diameters and configurations requiring careful planning
  • The existing tunnel profiles were complex and needed to be closely matched to maintain hydraulic capacity (9)

Solution Approach:

  • Slip lining with AmiRen pipe (a fiberglass reinforced polymer mortar pipe) was selected as the preferred rehabilitation method
  • The project utilized specialized equipment including a Tenbusch 12 DD-150 sliplining machine, prover mandrels, and hydraulic power unit
  • The new pipe profiles were designed to closely match the existing tunnel profiles to minimize hydraulic capacity loss (9)

Project Execution:

  1. The existing sewer was thoroughly inspected and cleaned to prepare for slip lining
  2. Access pits were constructed at strategic points along the pipeline route
  3. The AmiRen GRP pipes, manufactured by Amiantit in Poland and supplied by Thompson Pipe Group, were prepared for installation
  4. The pipes were inserted using the Tenbusch sliplining machine, which allowed for precise control during installation
  5. The annular space between the new pipe and existing tunnel was carefully grouted to ensure stability
  6. Specialized prover mandrels were used to verify proper installation and alignment (9)

Project Outcomes:

  • The project was completed with minimal disruption to traffic and surrounding businesses
  • The new AmiRen pipe provides superior corrosion resistance and structural strength compared to the original infrastructure
  • The close profile matching ensured minimal loss of hydraulic capacity
  • The rehabilitated sewer is expected to provide 50+ years of reliable service
  • The project demonstrated the effectiveness of slip lining for large-diameter, non-circular sewer pipelines in urban environments (9)

2.3 Spiral Wound Pipe Rehabilitation (SPR)

Spiral Wound Pipe Rehabilitation (SPR) is a specialized trenchless technology used in Los Angeles for rehabilitating large-diameter, non-circular sewer pipelines, particularly those with complex geometries .

Technology Description

SPR involves spirally winding a continuous strip of PVC or HDPE material inside the existing pipeline to form a new, structurally independent pipe. The interlocking edges of the strip create a watertight seal, and the process can be adapted to conform to various pipe shapes and sizes .

The SPR process typically involves the following steps:

  1. Pre-inspection and preparation: The existing pipe is inspected to determine its condition and suitability for SPR. The pipe is then cleaned and any obstructions are removed
  2. Equipment setup: A specialized winding machine is positioned in the manhole or access chamber at one end of the rehabilitation section
  3. Strip feeding: A continuous strip of PVC or HDPE material is fed into the winding machine, which spirally winds it into the existing pipe
  4. Winding process: The machine rotates as it advances along the pipe, creating a continuous spiral-wound liner with interlocking edges
  5. Joint sealing: The interlocking edges of the strip are sealed to create a watertight connection
  6. Final inspection: The completed installation is inspected to ensure proper alignment, sealing, and functionality

Material Selection

The choice of strip material depends on several factors, including:

  • Pipe size and configuration: Larger diameters may require stronger materials
  • Expected service conditions: Corrosive environments may necessitate more resistant materials
  • Pipe geometry: Non-circular pipes may require more flexible materials
  • Cost considerations: Different materials offer different cost-performance tradeoffs

In Los Angeles, the most commonly used SPR materials include:

  • Polyvinyl Chloride (PVC): Provides good rigidity and chemical resistance at a moderate cost
  • High-Density Polyethylene (HDPE): Offers greater flexibility and impact resistance, making it suitable for areas with potential ground movement
  • Reinforced PVC: Combines the advantages of PVC with added structural strength for larger diameter applications

Advantages of SPR

SPR offers several advantages that make it a valuable rehabilitation option in Los Angeles:

  1. Exact profile replication: Can precisely match the geometry of existing non-circular pipes, maintaining hydraulic efficiency
  2. Structural integrity: The continuous spiral-wound construction provides excellent structural stability
  3. Watertight seal: The interlocking edges create a highly effective watertight joint
  4. Adaptability: Can be used in pipes of various shapes (including elliptical, horseshoe, and rectangular) and sizes from 8" to 144" (20 cm to 366 cm)
  5. Minimal excavation: Requires only access points at manholes or other existing structures
  6. Long service life: With proper material selection and installation, SPR can provide 50+ years of service life

Case Study: Los Angeles County "JOINT OUTFALL A" Unit Rehabilitation

The "JOINT OUTFALL A" (JOA) unit rehabilitation project represents a significant application of SPR technology in Los Angeles County. This project involved rehabilitating a section of the county's sewer system that had been in service for over 80 years (3).

Project Challenges:

  • The existing sewer was a large, horseshoe-shaped structure with dimensions of 2.9 meters in both width and height
  • The pipeline included several sharp curves, including three 90-degree bends with a radius of only 18 meters (R/D=6.6)
  • The project needed to maintain hydraulic capacity while providing structural reinforcement
  • Traditional rehabilitation methods were deemed infeasible due to the complexity of the pipe geometry and the urban setting (3)

Solution Approach:

  • SPR technology was selected as the preferred rehabilitation method due to its ability to precisely replicate the existing pipe geometry
  • A specialized PVC strip material was chosen for its rigidity and chemical resistance properties
  • The project utilized a custom-designed winding machine capable of negotiating the tight curves in the pipeline (3)

Project Execution:

  1. The existing sewer was thoroughly inspected and cleaned to prepare for SPR installation
  2. The winding machine was positioned in the manhole at one end of the rehabilitation section
  3. The PVC strip was fed into the machine and spirally wound into the existing pipe, following the entire length of the rehabilitation section
  4. The machine carefully navigated the three 90-degree bends, maintaining precise alignment and strip tension
  5. The interlocking edges of the PVC strip were carefully sealed to ensure a watertight connection
  6. The completed installation was inspected using CCTV to verify proper alignment and sealing (3)

Project Outcomes:

  • The project successfully rehabilitated the complex, non-circular sewer section while maintaining full hydraulic capacity
  • The SPR installation effectively addressed the structural concerns and extended the service life of the pipeline by at least 50 years
  • The rehabilitation was completed with minimal disruption to the surrounding community and without significant traffic impacts
  • The project demonstrated the effectiveness of SPR technology for rehabilitating large-diameter, non-circular sewer pipelines with complex geometries
  • The success of this project has led to increased consideration of SPR for similar challenging rehabilitation projects throughout Los Angeles County (3)

2.4 Spray-Applied Pipe Lining (SAPL)

Spray-Applied Pipe Lining (SAPL) is a trenchless rehabilitation method used in Los Angeles for rehabilitating deteriorated gravity storm conduits and culverts, particularly those with complex geometries or challenging access conditions (52).

Technology Description

SAPL involves spraying a polymeric material directly onto the interior surface of the existing pipeline to form a continuous, seamless lining. The material cures in place to create a durable, corrosion-resistant barrier that restores structural integrity and improves hydraulic performance (52).

The SAPL process typically involves the following steps:

  1. Pre-inspection and preparation: The existing pipe is inspected to determine its condition and suitability for SAPL. The pipe is then thoroughly cleaned to remove debris, loose material, and corrosion products (52)
  2. Surface preparation: The interior surface of the pipe is roughened or treated to ensure proper adhesion of the spray material
  3. Spray equipment setup: Specialized spray equipment is positioned in the manhole or access chamber at one end of the rehabilitation section
  4. Spray application: The polymeric material is sprayed onto the interior surface of the pipe in multiple layers, building up to the required thickness
  5. Curing: The sprayed material is allowed to cure, either through chemical reaction, heat, or ambient conditions
  6. Post-inspection: The completed lining is inspected to ensure uniform thickness, proper adhesion, and functionality (52)

Material Selection

The choice of spray material depends on several factors, including:

  • Pipe size and configuration: Larger diameters may require different application techniques
  • Expected service conditions: Corrosive environments may necessitate more resistant materials
  • Pipe geometry: Complex shapes may require materials with different flow and curing characteristics
  • Cost considerations: Different materials offer different cost-performance tradeoffs (52)

In Los Angeles, the most commonly used SAPL materials include:

  • Polyurea: Offers rapid curing, high strength, and excellent chemical resistance
  • Polyurethane: Provides good flexibility and impact resistance, suitable for areas with potential ground movement
  • Epoxy: Offers superior adhesion and chemical resistance, ideal for severely corroded surfaces
  • Hybrid systems: Combine the advantages of multiple materials to meet specific project requirements (52)

Advantages of SAPL

SAPL offers several advantages that make it a valuable rehabilitation option in Los Angeles:

  1. Seamless application: Creates a continuous lining without joints, eliminating potential leak points
  2. Excellent adhesion: Bonds directly to the existing pipe surface, providing good structural integration
  3. Adaptability: Can be applied to various pipe materials (concrete, metal, etc.) and shapes (including non-circular)
  4. Thickness control: Material can be applied in varying thicknesses to address specific defect areas
  5. Minimal excavation: Requires only access points at manholes or other existing structures
  6. Rapid installation: Many SAPL materials cure quickly, reducing project duration (52)

Case Study: Fourth Avenue-Slauson Sewer Rehabilitation Project

The Fourth Avenue-Slauson Sewer Rehabilitation Project represents a significant application of innovative rehabilitation techniques, including elements of SAPL, in Los Angeles (1).

Project Challenges:

  • The project involved rehabilitating approximately 6,300 feet (1,920 meters) of 75-inch (190 cm) diameter lined RCP sewer
  • The most challenging section was a 200-foot (61 meter) long 90-degree bend located beneath the intersection of Fourth Avenue and Slauson Avenue, one of Los Angeles' busiest streets
  • Traditional rehabilitation methods were deemed infeasible due to the complexity of the bend and the high traffic volume in the area
  • The original contract called for open-cut repair, which would have caused significant traffic disruption and business impacts (1)

Solution Approach:

  • The contractor proposed an innovative approach using manual entry combined with specialized lining techniques instead of open-cut repair
  • The approach involved:
    1. Precise measurement of each deflection angle within the bend
    2. Custom fabrication of each pipe joint with bevels between 1-5 degrees to match the measured angles
    3. Installation of the custom joints using a combination of diesel-powered winches and manual labor
    4. Sealing and grouting of the joints to ensure structural integrity and watertightness (1)

Project Execution:

  1. The existing sewer was thoroughly inspected and surveyed to document the exact geometry of the bend
  2. Custom pipe joints were fabricated based on the survey data, with each joint precisely beveled to match the required angle
  3. Access points were established at strategic locations to facilitate manual entry and material handling
  4. The custom joints were installed one by one, with each joint carefully positioned and secured before proceeding to the next
  5. After all joints were installed, the annular space was grouted to provide structural stability and prevent groundwater infiltration
  6. The completed installation was inspected using CCTV and other methods to verify proper alignment and functionality (1)

Project Outcomes:

  • The innovative approach eliminated two of the four planned traffic control phases, significantly reducing traffic impacts
  • The project was completed ahead of schedule, with the 200-foot bend successfully rehabilitated by December 31, 2012
  • The custom joint design maintained full hydraulic capacity while providing the necessary structural reinforcement
  • The project demonstrated the effectiveness of combining traditional and innovative techniques for challenging sewer rehabilitation projects
  • The success of this approach has led to increased consideration of similar methods for other complex sewer rehabilitation challenges throughout Los Angeles (1)

3. Technology Comparison and Selection

Selecting the most appropriate trenchless rehabilitation technology for a given sewer pipeline requires careful consideration of multiple factors. This section provides a comparative analysis of the primary technologies discussed in this document, along with guidance for technology selection based on specific project conditions.

3.1 Comparative Analysis of Key Technologies

The following table provides a side-by-side comparison of the four primary trenchless rehabilitation technologies discussed in this document:

 

Technology Material Diameter Range Shape Adaptability Structural Capacity Installation Time Cost Considerations Service Life
CIPP Resin-impregnated felt or glass fiber 4" - 96" (10 cm - 244 cm) Excellent (including non-circular) Full structural Moderate (3-6 hours curing) Medium to high 50-100 years
Slip Lining HDPE, GRP, or PVC 6" - 144" (15 cm - 366 cm) Good (best for circular pipes) Full to partial structural Longer due to insertion and grouting Medium to high 50+ years
SPR PVC or HDPE strip 8" - 144" (20 cm - 366 cm) Excellent (including complex non-circular) Full structural Moderate to long Medium to high 50+ years
SAPL Polyurea, polyurethane, or epoxy 12" and larger Excellent (including complex geometries) Partial to full structural Short (rapid curing) Medium to high 30-50 years

Additional comparative considerations:

  1. Hydraulic Performance:
    • CIPP and SAPL provide the smoothest interior surfaces, resulting in excellent flow characteristics
    • SPR and slip lining also maintain good hydraulic performance when properly designed
    • All methods typically maintain or improve upon original flow capacity (24)
  2. Installation Complexity:
    • CIPP and SAPL generally require less specialized equipment and can be installed with relatively simple access
    • Slip lining and SPR often require more specialized equipment and careful planning, particularly for longer distances or complex geometries
    • All methods require skilled personnel for proper installation
  3. Environmental Considerations:
    • All four methods minimize excavation and associated environmental impacts compared to traditional open-cut methods
    • CIPP and SAPL may involve the use of potentially hazardous resins that require careful handling and ventilation
    • Slip lining and SPR typically involve fewer hazardous materials but generate more solid waste from packaging and excess materials (26)
  4. Repairability and Modifiability:
    • CIPP and SAPL create a monolithic lining that can be difficult to access for future repairs or modifications
    • Slip lining and SPR allow for potential future access through the annular space if properly designed
    • All methods require careful planning for future maintenance and potential modifications

3.2 Technology Selection Criteria

The selection of the most appropriate trenchless rehabilitation technology for a specific project should be based on a comprehensive evaluation of the following factors:

  1. Pipe Condition:
    • Extent of deterioration (structural vs. non-structural)
    • Presence and severity of corrosion
    • Degree of deformation or ovality
    • Presence of cracks, breaks, or other defects (20)
  2. Pipe Characteristics:
    • Diameter (small, medium, large)
    • Shape (circular, elliptical, horseshoe, etc.)
    • Material (concrete, clay, metal, etc.)
    • Length of section to be rehabilitated (20)
  3. Environmental and Site Conditions:
    • Groundwater conditions (high vs. low water table)
    • Soil type and stability
    • Presence of nearby utilities or structures
    • Proximity to sensitive environments or facilities (20)
  4. Operational Considerations:
    • Need to maintain service during rehabilitation
    • Allowable downtime
    • Traffic and access constraints
    • Noise and vibration limitations (20)
  5. Performance Requirements:
    • Required service life
    • Expected hydraulic capacity
    • Resistance to corrosion or chemical attack
    • Structural requirements (full vs. partial rehabilitation) (20)
  6. Cost Considerations:
    • Capital costs (material, equipment, labor)
    • Life-cycle costs (maintenance, future repairs)
    • Comparative costs of alternative technologies
    • Cost of service disruption during rehabilitation (26)

3.3 Decision-Making Framework

Based on the comparative analysis and selection criteria discussed above, the following decision-making framework can be used to guide technology selection:

  1. Determine Rehabilitation Objectives:
    • Is the primary objective structural reinforcement, leak prevention, corrosion protection, or improved hydraulic performance?
    • What is the required service life for the rehabilitated pipeline? (20)
  2. Evaluate Pipe Condition:
    • Conduct a thorough inspection using appropriate technologies (CCTV, sonar, etc.)
    • Assess the extent of deterioration and determine if the pipe is structurally sound enough for trenchless rehabilitation or if replacement is necessary (20)
  3. Assess Site and Environmental Conditions:
    • Evaluate groundwater conditions, soil stability, and proximity to sensitive areas
    • Determine access constraints and potential impacts on surrounding activities (20)
  4. Screen Potential Technologies:
    • Based on pipe characteristics, condition, and site conditions, identify technologies that are technically feasible
    • Eliminate technologies that are not suitable for the specific pipe diameter, shape, or condition (20)
  5. Evaluate Performance Requirements:
    • Compare the performance capabilities of the remaining technologies against the project's specific requirements
    • Consider factors such as structural capacity, hydraulic performance, chemical resistance, and service life (20)
  6. Conduct Cost Analysis:
    • Compare the capital and life-cycle costs of the remaining technologies
    • Consider the costs of service disruption and environmental impacts associated with each technology
    • Evaluate the cost-effectiveness of each option in terms of performance delivered per dollar spent (26)
  7. Make Final Selection:
    • Based on the technical feasibility, performance, and cost considerations, select the most appropriate technology
    • Consider local experience and expertise with the technology as a final factor in the decision-making process (20)

By following this structured decision-making framework, engineers can ensure that the most appropriate trenchless rehabilitation technology is selected for each specific project, maximizing both technical performance and cost-effectiveness.

4. Quality Control and Assurance

Maintaining high standards of quality control and assurance is essential for the successful implementation of trenchless sewer rehabilitation projects. This section outlines the key considerations for quality management in Los Angeles' sewer rehabilitation programs, including inspection protocols, material testing, and compliance with relevant standards.

4.1 Pre-Installation Inspection and Assessment

Thorough pre-installation inspection and assessment are critical to ensuring the success of any trenchless rehabilitation project. The following steps should be included in the pre-installation phase:

  1. Pipe Condition Assessment:
    • Conduct detailed inspection using CCTV, sonar, or other appropriate technologies
    • Document the condition of the pipe, including location and severity of defects
    • Identify any obstructions or debris that could interfere with the rehabilitation process
    • Determine the suitability of the pipe for the selected rehabilitation method (20)
  2. Geotechnical Investigation:
    • Evaluate soil conditions and groundwater levels
    • Identify potential risks from unstable soils or high groundwater
    • Determine appropriate measures to mitigate these risks during rehabilitation (20)
  3. Design Verification:
    • Review design documents to ensure they are based on accurate site and pipe conditions
    • Verify that the selected rehabilitation method and materials are appropriate for the specific conditions
    • Confirm that the design meets all relevant standards and specifications (20)
  4. Work Plan Review:
    • Evaluate the proposed work plan for feasibility and compliance with project requirements
    • Ensure that safety protocols and environmental protection measures are adequate
    • Confirm that the proposed schedule is realistic given the project constraints (20)

4.2 Material Quality Control

Ensuring the quality of materials used in trenchless rehabilitation is essential for achieving long-term performance. The following measures should be implemented to maintain material quality:

  1. Material Specifications:
    • Establish clear specifications for all materials used in the rehabilitation process
    • Specify acceptable materials, manufacturers, and product standards
    • Define performance requirements, including strength, durability, and chemical resistance (20)
  2. Material Testing:
    • Conduct laboratory testing of materials to verify compliance with specifications
    • Test physical properties such as tensile strength, flexural strength, and modulus of elasticity
    • Perform chemical resistance testing for materials intended for corrosive environments
    • Verify that resins meet curing requirements and adhesion specifications (53)
  3. Quality Documentation:
    • Require manufacturers to provide certificates of compliance for all materials
    • Maintain detailed records of material testing results
    • Track material batch numbers and dates of manufacture for traceability (20)
  4. Storage and Handling:
    • Establish proper storage conditions for materials to prevent deterioration
    • Develop procedures for safe handling of potentially hazardous materials
    • Implement controls to ensure materials are used before their expiration dates (20)

4.3 Installation Quality Control

Strict quality control during installation is critical to ensuring the performance of trenchless rehabilitation systems. The following measures should be implemented during the installation phase:

  1. Installation Monitoring:
    • Conduct regular inspections during installation to ensure compliance with approved methods
    • Monitor critical parameters such as resin curing temperature, pressure during inflation, and material application rates
    • Document all installation activities and any deviations from the approved plan (20)
  2. Process Validation:
    • Perform validation tests to ensure that the installation process is achieving the desired results
    • For CIPP installations, verify proper resin impregnation and curing
    • For slip lining and SPR, confirm proper alignment and joint integrity
    • For SAPL, ensure uniform material thickness and adhesion
  3. Defect Identification and Correction:
    • Establish procedures for identifying and documenting installation defects
    • Develop protocols for correcting defects promptly and appropriately
    • Implement a non-conformance reporting system for significant issues (20)
  4. Safety Compliance:
    • Ensure all installation activities comply with applicable safety standards
    • Implement appropriate personal protective equipment and confined space entry procedures
    • Monitor air quality in confined spaces to prevent exposure to hazardous fumes (20)

4.4 Post-Installation Inspection and Testing

Thorough post-installation inspection and testing are essential to verifying the success of trenchless rehabilitation projects. The following steps should be included in the post-installation phase:

  1. Visual Inspection:
    • Conduct detailed visual inspections of the rehabilitated pipeline using CCTV or other appropriate methods
    • Document the condition of the lining, including any visible defects or anomalies
    • Verify that all service connections have been properly reinstated (15)
  2. Structural Integrity Testing:
    • Perform structural integrity tests to verify the load-bearing capacity of the rehabilitated pipeline
    • For CIPP and SAPL, conduct inflation tests to ensure proper adhesion and structural performance
    • For slip lining and SPR, perform grout integrity tests to verify proper filling of the annular space
  3. Hydraulic Performance Testing:
    • Conduct flow tests to verify that the rehabilitated pipeline meets hydraulic performance requirements
    • Compare post-rehabilitation flow rates to pre-rehabilitation baseline data
    • Confirm that there are no restrictions or obstructions affecting flow (20)
  4. Leak Testing:
    • Perform leak tests to ensure the rehabilitated pipeline is watertight
    • For gravity sewers, conduct water testing to verify no infiltration or exfiltration
    • For pressure sewers, conduct air or water pressure tests to confirm pressure retention (20)
  5. Final Documentation:
    • Prepare comprehensive documentation of the rehabilitation project, including as-built drawings, material certifications, test results, and inspection reports
    • Create a maintenance manual for the rehabilitated pipeline, including recommended inspection intervals and maintenance procedures
    • Submit all documentation to the owner for inclusion in the asset management system (20)

4.5 Compliance with Standards and Specifications

Adherence to established standards and specifications is essential for ensuring the quality and consistency of trenchless rehabilitation projects. The following standards are particularly relevant to Los Angeles' sewer rehabilitation programs:

  1. ASTM Standards:
    • ASTM F1216: Standard Practice for Installation of Cured-in-Place Thermosetting Resin Pipe Lining Systems for Rehabilitation of Existing Pipelines and Conduits
    • ASTM F2561: Standard Practice for Rehabilitation of Sewers Using Cured-in-Place Lining in Combination with the Existing Pipe
    • ASTM D2657: Standard Practice for Heat Fusion Joining of Polyolefin Pipe and Fittings (relevant to slip lining and SPR) (16)
  2. ASCE Standards:
    • ASCE 38-02: Standard Guideline for the Collection and Depiction of Existing Subsurface Utility Data (relevant to pre-installation surveys)
    • ASCE Manual 60: Existing Sewer Evaluation and Rehabilitation: Provides guidance on sewer evaluation and rehabilitation planning (31)
  3. European Standards:
    • EN 13108: Series of standards for plastic piping systems used for the rehabilitation of pipelines
    • EN 13108-3: Specific requirements for CIPP systems (54)
  4. Local Standards and Specifications:
    • Los Angeles Bureau of Engineering Design Manual, Part F: Sewer Design
    • Requirements specific to the City of Los Angeles and Los Angeles County

By implementing robust quality control and assurance programs that incorporate these standards and best practices, Los Angeles can ensure that its trenchless sewer rehabilitation projects meet the highest standards of quality, reliability, and performance.

5. Emerging Trends and Innovations

The field of trenchless sewer rehabilitation is continuously evolving, with new technologies, materials, and techniques being developed to address the challenges of aging infrastructure. This section discusses some of the emerging trends and innovations that are shaping the future of sewer rehabilitation in Los Angeles and beyond.

5.1 Advanced Materials Development

The development of new and improved materials is revolutionizing trenchless sewer rehabilitation. Key advancements include:

  1. High-Strength Composites:
    • Glass fiber-reinforced CIPP liners that provide significantly higher strength and stiffness than traditional felt-based systems
    • Hybrid materials combining the advantages of different materials (e.g., polyester and epoxy resins)
    • Nano-engineered materials with enhanced properties such as self-healing capabilities (53)
  2. Environmentally Friendly Resins:
    • Low-VOC (volatile organic compound) resins that reduce environmental impact and improve worker safety
    • Bio-based resins derived from renewable resources
    • Rapid-curing resins that reduce project duration while maintaining performance (28)
  3. Smart Materials:
    • Materials embedded with sensors to monitor structural performance and detect potential problems early
    • Self-healing materials that can automatically repair minor cracks or defects
    • Thermochromic materials that change color in response to temperature or chemical exposure, providing visual indicators of potential issues (53)
  4. Corrosion-Resistant Coatings:
    • Advanced ceramic and metallic coatings for extreme corrosion resistance
    • Hydrophobic coatings that reduce biofilm formation and associated corrosion
    • Antimicrobial coatings that inhibit the growth of bacteria responsible for hydrogen sulfide production (51)

5.2 Digital Transformation and Smart Rehabilitation

The integration of digital technologies is transforming the practice of sewer rehabilitation, enabling more precise assessments, better decision-making, and improved project outcomes:

  1. Advanced Inspection Technologies:
    • Three-dimensional laser scanning for detailed pipe profiling
    • Ground-penetrating radar for assessing surrounding soil conditions
    • Autonomous inspection robots capable of navigating complex pipe networks (20)
  2. Digital Twins and Modeling:
    • Creation of digital twins of sewer systems for comprehensive analysis and planning
    • Advanced hydraulic modeling to optimize rehabilitation designs
    • Predictive modeling to estimate remaining service life and prioritize rehabilitation efforts (20)
  3. Real-Time Monitoring:
    • Installation of sensors during rehabilitation to monitor curing processes and structural performance
    • Remote monitoring systems for long-term performance tracking
    • IoT (Internet of Things) enabled manholes and pipelines for continuous condition assessment (20)
  4. Augmented Reality (AR) and Virtual Reality (VR):
    • AR applications for on-site guidance during complex rehabilitation projects
    • VR simulations for training purposes and design review
    • Mixed reality tools for visualizing rehabilitation options and their impacts (20)

5.3 Automated and Robotic Systems

The development of automated and robotic systems is improving the precision, efficiency, and safety of sewer rehabilitation:

  1. Automated Lining Systems:
    • Robotic CIPP installation systems with improved precision and reduced labor requirements
    • Automated spray systems for SAPL applications that ensure uniform material distribution
    • Self-propelled slip lining systems capable of negotiating complex geometries (52)
  2. Service Connection Reinstatement:
    • Robotic systems for precise reinstatement of service connections after CIPP installation
    • Automated cutting and sealing systems for accessing and reconnecting lateral lines
    • Drone-based systems for inspecting and repairing hard-to-reach areas (15)
  3. Underground Navigation and Positioning:
    • Advanced guidance systems for precise control of rehabilitation equipment
    • Underground GPS-like systems for accurate positioning of robotic devices
    • Machine vision systems for real-time adjustment of rehabilitation processes (20)
  4. Swarm Robotics:
    • Coordinated teams of small robots working together to complete rehabilitation tasks
    • Distributed intelligence systems that can adapt to unexpected conditions
    • Self-assembling robotic systems for complex rehabilitation challenges (20)

5.4 Integrated Rehabilitation Approaches

The future of sewer rehabilitation is moving toward more integrated approaches that consider the entire system rather than individual pipes:

  1. System-Wide Optimization:
    • Rehabilitation planning that considers the entire sewer system rather than individual pipes
    • Integration of rehabilitation with other infrastructure improvements such as stormwater management
    • Multi-objective optimization models that balance cost, performance, and risk (20)
  2. Life-Cycle Asset Management:
    • Comprehensive asset management systems that track the condition and performance of rehabilitated pipelines over their entire service life
    • Predictive maintenance strategies based on actual performance data
    • Economic analysis that considers the full life-cycle costs of rehabilitation options (20)
  3. Green Infrastructure Integration:
    • Combining traditional sewer rehabilitation with green infrastructure solutions to reduce hydraulic loads
    • Using permeable pavements and rain gardens to reduce infiltration and inflow
    • Integrating water quality improvements with structural rehabilitation (20)
  4. Community Engagement and Stakeholder Involvement:
    • Increased focus on engaging communities in the planning and implementation of rehabilitation projects
    • Collaborative decision-making processes that consider multiple perspectives
    • Transparent communication about project goals, methods, and expected outcomes (20)

5.5 Resilience and Climate Adaptation

As climate change presents new challenges, sewer rehabilitation is increasingly focused on building resilience into the system:

  1. Climate-Resilient Designs:
    • Rehabilitation designs that account for changing climate conditions, including increased rainfall intensity and prolonged droughts
    • Systems designed to withstand extreme weather events and changing groundwater conditions
    • Increased emphasis on redundancy and fail-safe mechanisms (42)
  2. Flood Risk Reduction:
    • Rehabilitation projects that incorporate flood prevention measures
    • Green infrastructure integration to reduce peak flows and flood risk
    • Improved capacity in strategic locations to accommodate increased flows (42)
  3. Water Reuse Integration:
    • Rehabilitation of sewers to support future water reuse applications
    • Systems designed to accommodate blended flows of wastewater and reclaimed water
    • Integration with decentralized water treatment systems
  4. Energy Efficiency:
    • Rehabilitation materials and methods that minimize energy consumption during installation and service
    • Systems designed to support energy recovery from wastewater
    • Integration with renewable energy systems where feasible (20)

By embracing these emerging trends and innovations, Los Angeles can continue to lead in the field of trenchless sewer rehabilitation, developing solutions that are more effective, efficient, and sustainable than ever before.

6. Conclusion

The trenchless sewer rehabilitation technologies employed in Los Angeles represent a significant advancement in infrastructure maintenance and renewal. By leveraging innovative methods such as CIPP, slip lining, SPR, and SAPL, the city is able to extend the service life of its aging sewer system while minimizing disruption to daily activities and reducing environmental impacts.

6.1 Key Findings

  1. Trenchless technologies offer significant advantages: The four primary technologies discussed in this document—CIPP, slip lining, SPR, and SAPL—all provide viable alternatives to traditional open-cut methods, offering reduced disruption, lower environmental impact, and competitive life-cycle costs (26).
  2. Technology selection must be based on specific conditions: There is no one-size-fits-all solution for sewer rehabilitation. The most appropriate technology depends on factors such as pipe condition, diameter, shape, site constraints, and performance requirements (20).
  3. Quality control and assurance are essential: Rigorous quality management throughout the entire rehabilitation process—from pre-installation inspection to post-installation testing—is critical to ensuring long-term performance and reliability (20).
  4. Innovation continues to drive improvements: The field of trenchless sewer rehabilitation is evolving rapidly, with new materials, technologies, and approaches continuously being developed to address emerging challenges and improve performance (20).
  5. System-wide and life-cycle perspectives are increasingly important: The future of sewer rehabilitation lies in integrated approaches that consider the entire system, long-term performance, and resilience to changing conditions (20).

6.2 Recommendations for Practice

Based on the experiences documented in this report, the following recommendations are offered for engineers and decision-makers involved in sewer rehabilitation projects:

  1. Adopt a systematic approach to technology selection: Develop and implement a structured decision-making framework that considers all relevant factors when selecting rehabilitation technologies (20).
  2. Invest in comprehensive condition assessment: Before selecting a rehabilitation method, conduct thorough inspections and assessments to fully understand the condition of the pipeline and its surrounding environment (20).
  3. Prioritize quality control and assurance: Implement robust quality management programs that address all phases of the rehabilitation process, from material selection to final testing (20).
  4. Stay informed about emerging technologies and materials: Regularly review new developments in trenchless rehabilitation and consider appropriate innovations for suitable projects (20).
  5. Take a system-wide perspective: When planning rehabilitation projects, consider how individual pipe repairs fit into the broader context of the entire sewer system and the community it serves (20).
  6. Embrace digital transformation: Leverage advanced digital technologies for inspection, design, implementation, and monitoring to improve project outcomes and reduce risks (20).
  7. Plan for resilience: Incorporate climate resilience and adaptation considerations into rehabilitation designs to ensure long-term performance in changing conditions (42).

By following these recommendations and continuing to innovate, Los Angeles and other cities can effectively address the challenges of aging infrastructure while building more sustainable, resilient, and cost-effective sewer systems for the future.

6.3 Future Outlook

The future of sewer rehabilitation in Los Angeles and elsewhere is bright, with continued innovation and advancement expected in the coming years. Key trends that will shape this future include:

  1. Increased automation and robotics: The development of more sophisticated robotic systems will continue to improve the precision, efficiency, and safety of trenchless rehabilitation (20).
  2. Advanced materials: The development of stronger, more durable, and more environmentally friendly materials will enhance the performance and sustainability of rehabilitated sewers (53).
  3. Digital integration: The integration of digital technologies throughout the entire rehabilitation process will enable more precise assessments, better decision-making, and improved outcomes (20).
  4. System-wide optimization: A greater emphasis on system-wide planning and optimization will lead to more efficient and cost-effective rehabilitation strategies (20).
  5. Climate resilience: Climate change will drive the development of more resilient sewer systems that can withstand extreme weather events and changing environmental conditions (42).
  6. Water resource recovery: The integration of sewer rehabilitation with water reuse and resource recovery initiatives will become increasingly important as cities seek to optimize water management .

As these trends develop, the practice of sewer rehabilitation will continue to evolve, offering increasingly effective solutions for maintaining and renewing this critical infrastructure. By embracing these developments while maintaining a focus on quality, safety, and sustainability, Los Angeles can ensure that its sewer system continues to serve the city effectively for generations to come.

参考资料

[1] Oro Loma Sewer Collection System Pipeline Rehabilitation and Replacement Project | US EPA https://www.epa.gov/wifia/oro-loma-sewer-collection-system-pipeline-rehabilitation-and-replacement-project

[2] 奇迹!洛杉矶在建隧道坍塌,31名工人全部安全获救-腾讯新闻 https://view.inews.qq.com/a/20250711A019W900

[3] 洛杉矶县公共工程部: 洛杉矶县公共工程部: 综合下水道维护区 综合下水道维护区 一般服务问题 一般服务问题(pdf) https://www.pw.lacounty.gov/smd/SMD/LACDPW_FAQs_Chinese.pdf

[4] 航拍洛杉矶一隧道坍塌致15人被困 塌方疑损毁通信线路与被困者断联(含视频)_手机新浪网 https://news.sina.cn/2025-07-10/detail-infeyhuu0417550.d.html?vt=4&pos=108&wm=3049_00061575692907&his=0

[5] 突发!洛杉矶6.3亿隧道工程塌方,31名工人惊险获救_施工_监测_人员 https://www.sohu.com/a/912571182_100207708

[6] 美国洛杉矶一在建隧道坍塌,至少15名工人被困,目前无法与受困人员取得联系-半岛网 http://www.bandao.cn/a/1752128683747325.html

[7] 6.305亿美元工程突发事故!洛杉矶隧道坍塌15人被困-抖音 https://www.iesdouyin.com/share/video/7525354287829994803/?did=MS4wLjABAAAANwkJuWIRFOzg5uCpDRpMj4OX-QryoDgn-yYlXQnRwQQ&from_aid=1128&from_ssr=1&iid=MS4wLjABAAAANwkJuWIRFOzg5uCpDRpMj4OX-QryoDgn-yYlXQnRwQQ&mid=7525354207994563382&region=&scene_from=dy_open_search_video&share_sign=PLNRMNu1Psi7SXbBUyT_hzGhP3dJ3ycG3A2xdUZSGgE-&share_version=280700&titleType=title&ts=1752646256&u_code=0&video_share_track_ver=&with_sec_did=1

[8] ??6.3亿美金污水项目隧道坍塌!洛杉矶15名工人奇迹获 洛杉矶消防局在威尔明顿隧道坍塌事故中救出15名工人 据洛杉矶消防局消息,周三晚7点58分左右,洛杉矶威尔明顿街区北菲格罗亚街1700号附近一处在建工业隧道发生坍塌,导致15名工人被困,距入口最远达6英里。 100多名消防员(包括城市搜救专家)迅速赶赴现场。坍塌导致与被困人员的通讯中断,救援人员只能依靠有限空间作业规程和空气监测设备,在狭窄的通道中推进救援。 当地时间晚9点前,洛杉矶消防局报告称,所有15名工人均已被找到并转移至地面,经确认无人受伤。亲临现场的市长卡伦·巴斯表示,在安全检查员对结构进行评估期间,城市资源将继续留在现场。 该隧道是为洛杉矶县建造的一个耗资约6.305亿美元的污水排放项目的一部分。目前当局尚未确定坍塌原因,洛杉矶消防局和职业安全部门已展开调查。-抖音

据洛杉矶消防局消息,周三晚7点58分左右,洛杉矶威尔明顿街区北菲格罗亚街1700号附近一处在建工业隧道发生坍塌,导致15名工人被困,距入口最远达6英里。 100多名消防员(包括城市搜救专家)迅速赶赴现场。坍塌导致与被困人员的通讯中断,救援人员只能依靠有限空间作业规程和空气监测设备,在狭窄的通道中推进救援。 当地时间晚9点前,洛杉矶消防局报告称,所有15名工人均已被找到并转移至地面,经确认无人受伤。亲临现场的市长卡伦·巴斯表示,在安全检查员对结构进行评估期间,城市资源将继续留在现场。 该隧道是为洛杉矶县建造的一个耗资约6.305亿美元的污水排放项目的一部分。目前当局尚未确定坍塌原因,洛杉矶消防局和职业安全部门已展开调查。-抖音

100多名消防员(包括城市搜救专家)迅速赶赴现场。坍塌导致与被困人员的通讯中断,救援人员只能依靠有限空间作业规程和空气监测设备,在狭窄的通道中推进救援。 当地时间晚9点前,洛杉矶消防局报告称,所有15名工人均已被找到并转移至地面,经确认无人受伤。亲临现场的市长卡伦·巴斯表示,在安全检查员对结构进行评估期间,城市资源将继续留在现场。 该隧道是为洛杉矶县建造的一个耗资约6.305亿美元的污水排放项目的一部分。目前当局尚未确定坍塌原因,洛杉矶消防局和职业安全部门已展开调查。-抖音

当地时间晚9点前,洛杉矶消防局报告称,所有15名工人均已被找到并转移至地面,经确认无人受伤。亲临现场的市长卡伦·巴斯表示,在安全检查员对结构进行评估期间,城市资源将继续留在现场。 该隧道是为洛杉矶县建造的一个耗资约6.305亿美元的污水排放项目的一部分。目前当局尚未确定坍塌原因,洛杉矶消防局和职业安全部门已展开调查。-抖音

该隧道是为洛杉矶县建造的一个耗资约6.305亿美元的污水排放项目的一部分。目前当局尚未确定坍塌原因,洛杉矶消防局和职业安全部门已展开调查。-抖音 https://www.iesdouyin.com/share/video/7525325478329322806/?did=MS4wLjABAAAANwkJuWIRFOzg5uCpDRpMj4OX-QryoDgn-yYlXQnRwQQ&from_aid=1128&from_ssr=1&iid=MS4wLjABAAAANwkJuWIRFOzg5uCpDRpMj4OX-QryoDgn-yYlXQnRwQQ&mid=7147964382215735304&region=&scene_from=dy_open_search_video&share_sign=zibq.HvD2ZXhpX_S7ZmlVnFrDW0C1OHzqPBoz8Pi.3k-&share_version=280700&titleType=title&ts=1752646256&u_code=0&video_share_track_ver=&with_sec_did=1

[9] Crew Overcomes Challenges to Completed La Cienega Interceptor Rehab | California Water Environment Association https://www.cwea.org/news/crew-overcomes-challenges-to-completed-la-cienega-interceptor-rehab/

[10] Interceptor Sewer Rehabilitation Phase 3 https://www.constructionjournal.com/projects/details/d8e369921f8144c49af947f7b1f6c47a.html

[11] Construction Of District 5 Interceptor Sewer Rehabilitation Phase 1 https://www.constructionjournal.com/projects/details/43d99338b72146fcac2cdfcceca033ad.html

[12] Access Water | Normandie Sewer Replacement/Rehabilitation Project - Rehabilitation Of Ailing... https://www.accesswater.org/publications/proceedings/-299536/normandie-sewer-replacement/rehabilitation-project---rehabilitation-of-ailing-sewer-in-the-city-of-los-angeles

[13] Lakewood Interceptor Tunnel Rehabilitation Project - The City of Lakewood, Ohio https://www.lakewoodoh.gov/lakewood-interceptor/

[14] North Interceptor Sewer Line Project | City of Bend https://www.bendoregon.gov/city-projects/infrastructure-projects/north-interceptor

[15] How to Complete a Proper CIPP Install| Trenchless Technology https://trenchlesstechnology.com/how-to-complete-a-proper-cipp-install/

[16] F2304 Standard Practice for Rehabilitation of Sewers Using Chemical Grouting https://www.astm.org/f2304-03.html

[17] Access Water | A COMPARATIVE ANALYSIS OF SEWER REHABILITATION STRATEGIES Application,... https://www.accesswater.org/publications/proceedings/-289605/a-comparative-analysis-of-sewer-rehabilitation-strategies-application--selection--and-effectiveness-in-practice

[18] New ASTM Standard for Sewer Line Rehabilitation Is Approved | NEWSROOM https://newsroom.astm.org/newsroom-articles/new-astm-standard-sewer-line-rehabilitation-approved

[19] Updated ASCE Manhole Guidelines Focus On Issues, Rehab Methods | Underground Construction https://undergroundinfrastructure.com/magazine/2010/february-2010-vol-65-no-2/features/updated-asce-manhole-guidelines-focus-on-issues-rehab-methods

[20] Existing Sewer Evaluation and Rehabilitation https://cedb.asce.org/CEDBsearch/record.jsp?dockey=0091317

[21] City of Los Angeles Rehabilitation of the North Outfall Sewer by Concrete Lining | Proceedings | Vol , No https://ascelibrary.org/doi/10.1061/40976(316)664

[22] Slip Lining Vs CIPP: What's the Difference? - Advanced Pipe Repair https://www.advancedpiperepair.com/slip-lining-vs-cipp/

[23] Comparison of Sliplining, Cured-in-Place Pipe (CIPP), and Close-fit... | Download Scientific Diagram https://www.researchgate.net/figure/Comparison-of-Sliplining-Cured-in-Place-Pipe-CIPP-and-Close-fit-renewal-methods_tbl3_331395598

[24] The Difference Between Cured-in-Place Pipe Lining and Sliplining | MCSP https://mcspinc.com/the-difference-between-cured-in-place-pipe-cipp-and-slip-lining/

[25] 排水管道非开挖修复技术的造价分析 http://www.zkpipe.com/newsinfo.asp?Cla=31&thex=1303

[26] 开挖修复与非开挖修复综合成本比较 http://www.zkpipe.com/newsinfo.asp?thex=1397&Cla=31

[27] 排水管道非开挖修复技术的造价分析_管道修复基地 http://m.toutiao.com/group/7259573486673314319/?upstream_biz=doubao

[28] 南昌市管道UV-CIPP紫光固化修复技术的成本优势主要体现在以下几个方面_施工_成本高_方法 https://m.sohu.com/a/837699751_120693612/

[29] 目前国内各种非开挖修复技术对比分-20231013144502.docx-原创力文档 https://m.book118.com/html/2023/1013/8125141063005141.shtm

[30] 管道非开挖修复技术:如何减少施工成本与环境影响? | 骏腾环境 https://www.juntenghj.com/xyzx/13197.html

[31] ASCE 38-02 - Standard Guideline for the Collection and Depiction of Existing Subsurface Utility Data | GlobalSpec https://standards.globalspec.com/std/613017/asce-38-02

[32] Rehabilitation of California - Orange County Regional Sewers - T2 Utility Engineers : T2 Utility Engineers https://t2ue.com/projects/rehabilitation-of-california-orange-county-regional-sewers/

[33] ISO 11295:2022(en), Plastics piping systems used for the rehabilitation of pipelines — Classification and overview of strategic, tactical and operational activities https://www.iso.org/obp/ui/#!iso:std:79752:en

[34] Pipe Rehabilitation | Seals & Profiles https://www.trelleborg.com/en/seals-and-profiles/products-and-solutions/pipe-rehabilitation

[35] ASCE Standard 20-96 - PDFCOFFEE.COM https://pdfcoffee.com/asce-standard-20-96-pdf-free.html

[36] ASCE Standard 20 Standard Guidelines for the Design and Installation of Pile Foundations, 1996 - MADCAD.com https://www.madcad.com/store/subscription/ASCE-20-96/

[37] Large-Diameter, Non-Circular Trunk Sewer Rehabilitation Using GRP Composites | Proceedings | Vol , No https://ascelibrary.org/doi/10.1061/9780784479957.153

[38] ASTM-D2657 | Standard Practice for Heat Fusion Joining of Polyolefin Pipe and Fittings | Document Center, Inc. https://www.document-center.com/standards/show/ASTM-D2657

[39] D2657 Standard Practice for Heat Fusion Joining of Polyolefin Pipe and Fittings https://www.astm.org/d2657-97.html

[40] ASTM D2657 : Standard Practice for Heat Fusion Joining of Polyolefin Pipe and Fittings https://global.ihs.com/doc_detail.cfm?document_name=ASTM%20D2657&item_s_key=00016810

[41] Trelleborg CIPP Lining | Seals & Profiles https://www.trelleborg.com/fr-fr/seals-and-profiles/produits-et-solutions/pipe-rehabilitation/method/trelleborg-cipp-lining

[42] The Role of Resilience in the Rehabilitation Planning of Water Pipeline Systems | Proceedings | Vol , No https://ascelibrary.org/doi/10.1061/9780784479957.173

[43] Structural Repair of a 42-Inch (1,067 mm) Steel Water Main | Proceedings | Vol , No https://ascelibrary.org/doi/10.1061/40690%282003%2946

[44] University of Alberta: Large Diameter Twin Raw Water Intake Pipeline Inspection, Condition Assessment, and Rehabilitation | Proceedings | Vol , No https://ascelibrary.org/doi/10.1061/9780784485026.037

[45] Mangas y mangueras de calibración (CIPP) | Seals & Profiles https://www.trelleborg.com/es-es/seals-and-profiles/productos-y-soluciones/rehabilitación-de-tuberías-“sin-zanja”/consumable-material/liner-and-glass-fiber-mats/mangas-y-mangueras-de-calibración

[46] EN 13108-31:2019 | Normas AENOR https://tienda.aenor.com/norma-cen-en-13108-31-2019-65663

[47] Codes and Compliance – Pipe Lining Equipment | CIPP Lining Manufacturer | Pipe Lining Companies https://www.internalpipetech.com/codes-and-compliance/

[48] Cipp Lining | Cured-In-Place Pipe (CIPP) Lining https://nuflow.com/blog/cipp-lining-success-3-factors-consider-pipe-lining-job/

[49] Host Pipe Condition II – Standardised Statics | unitracc.com https://www.unitracc.com/e-learning/modules/be-13-renovation-lining-with-cured-in-place-pipes-processes-v01/ppt_view?uid=uid-0b8487e44e1d4ef3971eef5638175215

[50] CIPP: Annular space and structural integrity | SAERTEX multiCom https://www.saertex-multicom.de/en/blog/cipp-annular-space-and-structural-integrity

[51] Water | Free Full-Text | The Mechanical Properties of High Strength Reinforced Cured-in-Place Pipe (CIPP) Liner Composites for Urban Water Infrastructure Rehabilitation https://www.mdpi.com/2073-4441/10/8/983

[52] Evaluation of CIPP Design Equation for Polymeric Spray Applied Pipe Lining | Proceedings | Vol , No https://ascelibrary.org/doi/abs/10.1061/9780784483626.013

[53] Short- and Long-Term Structural Characterization of Cured-in-Place Pipe Liner with Reinforced Glass Fiber Material - PubMed https://pubmed.ncbi.nlm.nih.gov/32245052/

[54] BS EN 13108-3:2016 Bituminous mixtures. Material specifications Soft Asphalt https://www.en-standard.eu/bs-en-13108-3-2016-bituminous-mixtures-material-specifications-soft-asphalt/

[55] Polychlorinated Biphenyl (PCB)-Containing Fluorescent Light Ballasts (FLBs) in School Buildings | US EPA https://www.epa.gov/pcbs/polychlorinated-biphenyl-pcb-containing-fluorescent-light-ballasts-flbs-school-buildings

[56] A13.1 - Scheme for the Identification of Piping Systems - ASME https://www.asme.org/codes-standards/find-codes-standards/a13-1-scheme-identification-piping-systems

THE END