Compressed Liners for Excavation-Free Manhole and Sewer Repair

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Solution Overview

Problem

Aging sewer systems, including manholes and sewer lines, deteriorate due to cracking and fissuring, leading to water infiltration, increased maintenance costs, and overflow issues, with existing repair methods being costly and ineffective in providing long-term solutions.

Innovation Solution

A method involving the insertion of a compressible liner into manholes and sewer lines, which expands to fit the structure, is bonded with a resin, and sealed with a bonding material to reinforce the walls, providing a water-tight seal and structural strength, allowing for installation without excavation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If excavation and removal of damaged pipe or manhole is performed, then the damaged structure can be completely replaced, but the cost increases significantly and street repairs are required

Engineering Contradiction:
Improvestructural integrityVSAvoidrepair cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent applies nesting by inserting a new liner inside the existing damaged manhole or sewer line structure. The liner is pulled through the existing structure and expanded to fit within it, creating a nested configuration where the new repair structure is contained within the old damaged structure. This eliminates the need for excavation and removal, providing complete structural replacement while avoiding costly street repairs.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent extracts the damaged structure by pulling the liner through the existing manhole or sewer line using a retrieval device. The liner is extracted from its compressed transport state and pulled through the damaged area, leaving the old structure in place while replacing its functional capacity. This extraction approach allows repair without excavation.

Inventive Principle:
Principle #2Taking out (Extraction)

2Object-affected harmful factors

If cement mixture or resin coating is applied to seal cracks, then the cracks can be sealed, but the method is not sufficient for holes and crevasses and is not a long-term fix

Engineering Contradiction:
Improvewater infiltrationVSAvoidlong-term durability
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent uses a flexible liner made of materials such as high-density polyethylene, polyvinyl chloride, or fiberglass that can conform to the internal geometry of the existing manhole or sewer line. This flexible shell provides a complete waterproof barrier that seals all cracks, holes, and crevasses, not just surface-level defects. The liner's flexibility allows it to accommodate structural movements while maintaining its sealing function, providing long-term durability.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The patent employs composite material construction for the liner, combining multiple materials to achieve both flexibility and structural integrity. The liner may consist of layered composite structures that provide waterproofing, structural support, and flexibility simultaneously. This composite approach creates a reliable long-term solution that addresses all types of damage including holes and crevasses that simple cement coatings cannot seal.

Inventive Principle:
Principle #40Composite materials

3Reliability

If pipe bursting method is used to replace old pipe, then a new pipe can be installed, but the method does not adequately address leaks and damage in the walls of sewer lines and manholes

Engineering Contradiction:
Improvepipe replacementVSAvoidwall deterioration
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent creates a universal repair solution that addresses multiple types of damage simultaneously. The liner not only replaces the pipe function but also seals cracks, holes, and crevasses in the walls, and provides structural reinforcement. This multi-functional approach handles pipe replacement, waterproofing, and structural repair in a single intervention, unlike pipe bursting which only replaces the pipe.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent segments the repair function into distinct components: the liner provides waterproofing and sealing, the bonding material adheres the liner to the existing structure, and the expansion mechanism ensures proper fit. This segmentation allows each component to address specific aspects of the damage, including wall deterioration, while working together to provide comprehensive repair.

Inventive Principle:
Principle #1Segmentation

4Reliability

If total replacement of manhole is performed, then complete structural integrity can be achieved, but excavation and street repairs are required making it expensive

Engineering Contradiction:
Improvestructural integrityVSAvoidrepair time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent uses the existing manhole or sewer line structure as an intermediary to install the repair liner. Instead of removing the old structure and building a new one from scratch, the liner is pulled through and expanded within the existing structure. This intermediary approach allows complete structural replacement while avoiding excavation and street repairs, significantly reducing repair time.

Inventive Principle:
Principle #24Intermediary (Mediator)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The method significantly reduces water infiltration, lowers maintenance and treatment costs, and extends the lifespan of manholes and sewer lines by up to 50%, while maintaining structural integrity and preventing chemical deterioration.

Implementation Method 1

A compressed liner that will expand to fit in the manhole is inserted through an access hole or the connected sewer lines

Methodology Applied
Scientific EffectElastic expansion: Elasticity

Implementation Method 2

A bonding material is injected between the liner and the manhole surface to seal any cracks or fissures in the brick or concrete walls and to seal the liner against the existing manhole

Methodology Applied
Scientific EffectAdhesion: Adhesive

Implementation Method 3

the liner should be expanded and bonded together with a resin along the separation line

Methodology Applied
Scientific EffectChemical bonding: Chemical Bonding

Data Source

PatentEP3946892B1Methods for rehabilitating, repairing, and replacing manholes and connected sewer lines
Publication Date: 2025.08.27 RESINATING LLC
  • EP3946892B1 patent drawingFigure 1~3
  • EP3946892B1 patent drawingFigure 4
  • EP3946892B1 patent drawingFigure 5~6

AI summary

The present invention is a method for rehabilitating, repairing, and replacing manholes and connected sewer lines. In some embodiments, a compressed liner is inserted through the manhole access hole or the connected sewer lines. Prior to insertion, the liner may be cut and/or folded to be compressed to a size that can fit through the manhole opening or the sewer lines. Once inserted in the manhole or sewer lines, the liner should be expanded, and if necessary, bonded together with a resin along the separation line. Next, a bonding material may be injected between the liner and a surface of the manhole or sewer line to seal any cracks or fissures in the brick or concrete wall and to seal the liner against the existing manhole or sewer line to improve structural integrity and longevity. A new corbel may then be installed and bonded to the liner.