A trenchless pipe rehabilitation liner structure

Abstract

The utility model relates to the field of pipeline repair, especially a trenchless pipeline repair lining pipe structure. The existing underground pipeline is influenced by external traffic load, accumulated load and construction load pressure and soil self-weight stress transmission, soil pressure can produce ring stress concentration at the edge of underground pipeline defect, forms the 'point breaks surface' damage effect, finally leads to lining pipe structure damage failure. A trenchless pipeline repair lining pipe structure, including flexible adhesion layer, rigid support layer and reinforcing layer, the flexible adhesion layer is two, wherein one flexible adhesion layer is attached to the pipe wall, and the other flexible adhesion layer is attached to the surface of the air bag. The glass fibers in the polyester fibers in the inner and outer layers also cross to form a glass fiber rigid net, improving the axial and lateral rigid support force, repairing the underground pipeline while dealing with the complex underground pipeline conditions of ring soil pressure and axial displacement.

Description

Technical Field

[0001] This utility model relates to the field of pipeline repair, and more particularly to a trenchless pipeline repair liner structure. Background Technology

[0002] As a key component of urban underground pipe networks, underground pipelines are prone to damage such as cracks or corrosion holes due to long-term exposure to soil circumferential pressure, uneven settlement, and groundwater corrosion.

[0003] Currently, trenchless in-situ curing is commonly used to repair such problems. This method combines single glass fiber and polyester fiber with unsaturated polyester resin to form a liner structure. An air bladder is placed to align the middle of the liner with the defect, and the air bladder is inflated to make the liner fit against the pipe wall, thus achieving pipe repair in a "pipe-in-pipe" form. However, due to the influence of external traffic loads, accumulation loads, construction load pressure, and the stress transmitted by the soil's own weight, soil pressure will generate stress at the edge of the defect that exceeds the circumferential stiffness and axial tensile strength of that range, forming a "point-to-surface" destructive effect, making the middle of the liner more prone to inward convex deformation.

[0004] In existing technologies, while transverse winding of glass fiber in fiberglass and polyester fiber hybrid structures can improve circumferential stiffness, it results in insufficient axial tensile strength around the defect. Vertical winding, on the other hand, improves axial tensile strength but reduces circumferential stiffness. Therefore, when repairing underground pipeline defects using a "pipe-in-pipe" approach, neither simple transverse nor vertical winding can adequately address both circumferential stiffness and axial tensile strength. The repaired pipeline still poses safety hazards and is prone to re-damage, leading to unsatisfactory repair results.

[0005] Therefore, this invention provides a trenchless pipeline repair liner structure that improves the overall annular stiffness and axial tensile strength of the liner, thus solving the problem caused by insufficient annular stiffness and axial tensile strength. Utility Model Content

[0006] To overcome the above-mentioned shortcomings, this utility model provides a trenchless pipeline repair liner structure.

[0007] The technical solution of this utility model is:

[0008] A trenchless pipeline repair liner structure includes a liner comprising an adhesive layer and a reinforcing layer. The adhesive layer consists of inner and outer adhesive layers, with the inner layer bonded to an air bladder and the outer layer bonded to the pipe wall. The reinforcing layer is disposed between the inner and outer layers and includes a spiral braided section and a V-shaped braided section. The V-shaped braided section has two regions located in the upper and lower regions of the reinforcing layer, respectively. The spiral braided section is located between the two regions of the V-shaped braided section, thereby forming a reinforcing structure with three-segment braiding.

[0009] The reinforcing layer includes a spiral braided section and a V-shaped braided section. The spiral braided section is located in the middle of the reinforcing layer, wherein the glass fiber forms a circumferential structure to form a rigid support. The V-shaped braided sections are located at both ends of the reinforcing layer, and the two V-shaped braided sections are respectively connected to the two ends of the spiral braided section, wherein the glass fiber forms a ring-shaped vertical V-shaped structure to form an axial tensile resistance system.

[0010] The glass fiber circumferential structure of the spiral braided section is specifically a ring-shaped spiral winding braid.

[0011] The glass fiber annular vertical V-shaped structure of the two V-shaped mixed weave sections is specifically woven through bidirectional vertical V-shaped cross weave.

[0012] The spiral braided section and the V-shaped braided section, except for the glass fiber portion, are all woven from polyester fibers in a complementary manner.

[0013] The rigid support layer is composed of three structural layers that are tightly bonded together from the inside out. The three structural layers are divided into an inner layer, a middle layer, and an outer layer.

[0014] The rigid support layer is formed by bonding three structural layers together with an unsaturated polyester fiber resin coating.

[0015] The inner, middle, and outer layers of the rigid support layer are respectively a vertically spaced mixed-weave layer, a glass fiber layer, and a horizontally spaced mixed-weave layer.

[0016] The vertically spaced mixed-weave layer and the horizontally spaced mixed-weave layer are woven from glass fiber and polyester fiber in alternating layers.

[0017] The inner and outer layers of the rigid support layer are interwoven with glass fiber mesh and polyester fiber mesh.

[0018] The beneficial effects of this utility model are: 1. Through segmented optimization, the glass fiber in the spiral braided part forms a circumferential spiral structure to form a rigid support skeleton to cope with transverse stress. The remaining part is polyester fiber, which has good flexibility and can adapt to a certain amount of deformation to alleviate stress peaks, avoiding brittle fracture caused by "excessive stiffness". It can also adapt to the expansion and enlargement of the airbag during the repair process of opening the liner, limiting stress diffusion and preventing the formation of secondary defects. The glass fiber with the circumferential vertical V-shaped cross structure has the glass fiber direction consistent with the pipeline axis, which can effectively resist the axial tensile stress caused by uneven settlement of the foundation.

[0019] 2. The rigid support layer provides rigid support through a pure glass fiber layer, which also serves as a reference layer. The polyester fibers in the inner and outer layers combine to form a cross-mesh, which not only resists axial tension but also alleviates the peak lateral stress through elastic deformation. At the same time, the glass fibers in the polyester fibers in the inner and outer layers also cross to form a glass fiber rigid mesh, which improves the axial and lateral rigid support force. This allows for the repair of underground pipelines while dealing with the complex underground pipeline conditions of circumferential earth pressure and axial displacement. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the three-dimensional structure of the liner of this utility model.

[0021] Figure 2 This is a three-dimensional structural diagram of the liner tube of this utility model in axial section.

[0022] Figure 3 This is a schematic diagram of the vertical and horizontal three-dimensional structure of the reinforcing layer of this utility model.

[0023] Figure 4 This is a schematic diagram of the vertical and horizontal three-dimensional structure of the vertically spaced mixed-weave layer and the horizontally spaced mixed-weave layer of this utility model.

[0024] The markings in the attached diagram are: 1. Inner layer; 2. Vertically spaced mixed layer; 3. Fiberglass layer; 4. Horizontally spaced mixed layer; 5. Reinforcing layer; 6. Outer layer. Detailed Implementation

[0025] The following is for reference only. Figure 1 -Appendix Figure 4 The embodiments of this utility model will be described.

[0026] Example 1:

[0027] A trenchless pipeline repair liner structure includes a liner comprising an adhesive layer and a reinforcing layer 5. The adhesive layer consists of inner and outer adhesive layers 1, with the inner adhesive layer 1 bonded to an air bladder and the outer adhesive layer 6 bonded to the pipe wall. The reinforcing layer 5 is disposed between the inner and outer layers and includes a spiral braided section and a V-shaped braided section. The V-shaped braided section has two regions located in the upper and lower regions of the reinforcing layer 5, respectively. The spiral braided section is located between the two regions of the V-shaped braided section, thereby forming a reinforcing structure with three-segment braiding.

[0028] The system consists of two bonding layers, both composed of polyester fibers. Utilizing the excellent flexibility (tensile strength) and strong adhesion of polyester fibers, the airbag layer (typically an elastic material) and the tube wall layer can be tightly bonded via chemical bonding. This reduces the risk of delamination due to material differences at the interface, improving the overall structural integrity. The chemical bonding method uses unsaturated polyester fiber resin, a commonly used thermosetting matrix material. In the polyester fiber layer and glass fiber layer 3, it primarily functions as an adhesive, load transfer medium, and protective reinforcement. The two flexible bonding layers are an inner layer 1 and an outer layer 6. The outer layer 6 adheres to the tube wall on one side, while the inner layer 1 adheres to the airbag surface. The properties of polyester fibers enhance the adhesion of the bonding surfaces. A rigid support layer is applied and bonded between the inner layer 1 and the outer layer 6 using adhesive (i.e., unsaturated polyester fiber resin). The unsaturated polyester fiber resin weaves the polyester fiber material into a... The filling of tiny gaps improves the integrity of the inner layer 1 and the outer layer 6, and also strengthens the polyester fiber material, so that a rigid seal is formed after curing, blocking the leakage of groundwater and sewage. At the same time, the adhesion of the unsaturated polyester fiber resin to the inner layer 1 and the outer layer 6 is equivalent to that of an interface adhesive, so that the liner can be heated by ultraviolet light irradiation or heating method using existing technology to form a multi-layer "pipe in pipe" structure. The outer layer 6 is attached to the pipe wall to complete the repair of the pipe wall. Between the flexible bonding layer and the rigid support layer attached to the pipe wall, a reinforcing layer 5 composed of glass fiber and polyester fiber is applied and bonded through unsaturated polyester fiber resin. Due to the high strength and rigidity of glass fiber and the good flexibility and strong adhesion of polyester fiber, the reinforcing layer 5 combines glass fiber and polyester fiber in a "soft" and "hard" way, which can adapt to the complex working conditions of underground pipelines that simultaneously bear circumferential earth pressure and axial displacement.

[0029] Underground pipelines are highly susceptible to damage due to long-term exposure to soil circumferential pressure, uneven settlement, and groundwater corrosion, leading to cracks and corrosion holes. While existing technologies combine single glass fibers and polyester fibers with unsaturated polyester resin, or blend the two together and combine them with unsaturated polyester resin to form a liner structure for pipeline repair in a "pipe-in-pipe" manner, the glass fibers in the blended structure are typically interleaved horizontally or vertically. Horizontal interleaving increases circumferential stiffness but lacks sufficient axial tensile strength, making it prone to cracking under axial stress caused by foundation settlement. Vertical interleaving increases axial tensile strength but reduces circumferential stiffness, failing to effectively offset the elliptical deformation of the pipeline. Therefore, when underground pipelines have defects such as cracks and holes, the soil pressure, influenced by external traffic loads, accumulated loads, construction loads, and the stress transmitted from the soil's own weight, causes circumferential stress concentration at the defect edges, creating a "point-to-surface" destructive effect, ultimately leading to damage and failure of the liner structure.

[0030] To address this, this application proposes a reinforcing layer 5, which includes a spiral braided section and a V-shaped braided section. Since the circumferential stress concentration is greatest at the center of the liner where the pipe damage occurs during repair, the spiral braided section is located in the center of the reinforcing layer 5. The spiral braided section employs a combination of soft and hard materials to specifically reinforce the pipe damage. The glass fiber in the spiral braided section forms a rigid support skeleton with a circumferential spiral structure to cope with lateral stress. The remaining part is made of polyester fiber, which, due to its good flexibility, can adapt to a certain amount of deformation to alleviate stress peaks and avoid brittle fracture caused by excessive stiffness. It also adapts to the expansion of the liner during the repair process, limiting stress diffusion and preventing secondary defects. The two ends of the liner are bonded to the pipe wall at a distance from the damage site for reinforcement. Therefore, the V-shaped braided sections are located at both ends of the reinforcing layer 5, with two V-shaped braided sections connecting to the two ends of the spiral braided section. The glass fiber has a circumferential vertical V-shaped cross structure, meaning the glass fiber forms a V-shape along the pipe axis. The interlaced glass fibers form an axial tensile resistance system, enhancing axial tensile and shear resistance and preventing tearing or delamination at the liner edges. The spiral and V-shaped interlaced sections, excluding the glass fiber portion, are entirely woven from polyester fibers, complementing each other. The role of the polyester fibers is the same as that in the spiral interlaced section. The difference lies in the glass fiber of the annular vertical V-shaped interlaced structure, where the fiber direction is aligned with the pipe axis. This effectively resists axial tensile stress caused by uneven foundation settlement. Simultaneously, the rigidity of the glass fiber buffers the interfacial shear stress generated if the central spiral interlaced section suddenly becomes axially fractured at the edge. Therefore, this annular vertical V-shaped interlaced glass fiber structure further strengthens the reinforcement of the central spiral interlaced section at pipe damage points.

[0031] Based on the above, it is known that the stress at the damaged part of the pipeline gradually increases over time. Simultaneously, the entire pipeline is subjected to external influences, namely traffic loads, accumulator loads, construction loads, and the soil's own weight stress. This causes the reinforcement layer 5 to shift, deform unevenly, and not adhere tightly, resulting in limited improvement of the repaired pipeline. Therefore, this application also proposes a rigid support layer to extend the service life of the repaired pipeline and reduce the risk of secondary repairs. The rigid support layer consists of three structural layers tightly bonded from the inside out, with the inner diameter of each layer increasing sequentially. The three structural layers are divided into an inner layer, a middle layer, and an outer layer. The bonding method between the three structural layers of the rigid support layer is through unsaturated polyester fiber resin coating. The inner, middle, and outer layers of the rigid support layer are respectively a vertically spaced mixed-weave layer 2 (inner layer), a glass fiber layer 3 (middle layer), and a horizontally spaced mixed-weave layer 4 (outer layer). The vertically spaced mixed-weave layer 2 and the... The transversely spaced mixed-braid layer 4 is composed of glass fiber and polyester fiber, while the inner vertically spaced mixed-braid structure is also composed of glass fiber and polyester fiber. Therefore, it forms a spaced "vertical skeleton" along the pipe's axial direction (length), which limits excessive axial stretching or compression deformation of the entire liner and prevents longitudinal slippage and stretching of the liner due to thermal expansion and contraction or uneven stress, thus enhancing its resistance to longitudinal tension. The middle circumferential pure glass fiber layer 3 forms a stiffness support layer along the pipe's circumference, limiting excessive radial expansion or contraction and also acting as a circumferential limiter to maintain the stability of the pipe's inner diameter. As a middle layer, it also separates the inner and outer mixed-braid layers, preventing stress concentration caused by direct contact between the inner and outer layers. The outer transverse mixed-braid structure is also composed of glass fiber and polyester fiber, forming a "vertical skeleton" along the pipe's circumference or transverse direction (perpendicular to the axial direction), together with the second glass fiber layer 3, forming a continuous grid. This "circumferential limiting network" further restricts the radial deformation of the liner (such as ellipticization), enhances its resistance to external stress, and further increases the overall lateral support of the reinforcing layer 5 for the pipeline. Therefore, the rigid support layer provides rigid support through the pure glass fiber layer 3, which is also the reference layer. The polyester fibers in the inner and outer layers combine to form a cross-net, which not only resists axial tension but also alleviates the peak lateral stress through elastic deformation. At the same time, the glass fibers of the polyester fibers in the inner and outer layers also cross to form a glass fiber rigid net, which improves the axial and lateral rigid support. In other words, this rigid support layer is equivalent to having two glass fiber layers 3 and a single polyester fiber layer. However, compared to a single layer, the inner and outer layers have the characteristics of two materials. Therefore, it can deal with the complex underground pipeline situation of circumferential earth pressure and axial displacement while repairing the underground pipeline.

[0032] When performing trenchless pipeline repair on underground pipelines, workers use an airbag on the ground. This airbag is cylindrical, with a thin film wrapped around its surface and coated with unsaturated polyester fiber resin. Then, an inner layer 1 (all polyester fiber material), a vertically spaced mixed-braid layer 2, a fiberglass layer 3, a horizontally spaced mixed-braid layer 4, a reinforcing layer 5 (mixed-braid layer), and an outer layer 6 (all polyester fiber material) are wrapped sequentially. A certain thickness of unsaturated polyester fiber resin is applied between each layer to eliminate gaps, ensuring a consistent and integrated lining. The columnar airbag and liner are vertically placed into the pipeline to be repaired. When the columnar airbag and liner are moved to the damaged area of ​​the pipeline, air is injected into the columnar airbag to make it expand and is held for a certain period of time until the outer layer of the liner (outer liner 6) adheres to the pipe wall. Then the columnar airbag is deflated to shrink it and the adhesion between the columnar airbag and the inner liner 1 is cut off. The unsaturated polyester fiber resin is cured using an ultraviolet curing device to further integrate each layer of the liner and make the adhesion between the inner liner 1 and the pipe wall stronger, thus completing the trenchless repair of the damaged area of ​​the underground pipeline.

[0033] The above embodiments are merely preferred embodiments of the present utility model and are not intended to limit the scope of the present utility model. Therefore, all equivalent changes made based on the content of the claims of the present utility model should be included within the scope of the claims of the present utility model.

Claims

1. A trenchless pipeline repair liner structure, characterized in that: The liner includes a bonding layer and a reinforcing layer (5). The bonding layer consists of inner and outer bonding layers. The inner bonding layer (1) is bonded to the airbag, and the outer bonding layer (6) is bonded to the tube wall. The reinforcing layer (5) is located between the inner and outer layers. The reinforcing layer (5) includes a spiral braided section and a V-shaped braided section. The V-shaped braided section is a double region located in the upper and lower regions of the reinforcing layer (5). The spiral braided section is located between the V-shaped braided sections in the double region, thereby forming a reinforcing structure with three-segment braiding.

2. The trenchless pipeline repair liner structure according to claim 1, characterized in that, The glass fiber circumferential structure of the spiral braided section is specifically a ring-shaped spiral winding braid.

3. The trenchless pipeline repair liner structure according to claim 1, characterized in that, The glass fiber annular vertical V-shaped structure of the two V-shaped mixed weave sections is specifically woven through bidirectional vertical V-shaped cross weave.

4. The trenchless pipeline repair liner structure according to claim 1, characterized in that, The spiral braided section and the V-shaped braided section, except for the glass fiber portion, are all woven from polyester fibers in a complementary manner.

5. The trenchless pipeline repair liner structure according to claim 1, characterized in that, It also includes a rigid support layer, which is located between the bonding layer and the reinforcing layer (5). The rigid support layer is composed of three structural layers that are tightly bonded together from the inside to the outside. The three structural layers are divided into an inner layer, a middle layer and an outer layer.

6. The trenchless pipeline repair liner structure according to claim 5, characterized in that, The rigid support layer is formed by bonding three structural layers together with an unsaturated polyester fiber resin coating.

7. The trenchless pipeline repair liner structure according to claim 6, characterized in that, The inner, middle and outer layers of the rigid support layer are respectively a vertically spaced mixed braided layer (2), a glass fiber layer (3) and a transversely spaced mixed braided layer (4).

8. The trenchless pipeline repair liner structure according to claim 7, characterized in that, The vertically spaced mixed-weave layer (2) and the horizontally spaced mixed-weave layer (4) are woven from glass fiber and polyester fiber in alternating layers.

9. The trenchless pipeline repair liner structure according to claim 6, characterized in that, The inner and outer layers of the rigid support layer intersect to form a glass fiber mesh and a polyester fiber mesh.

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