Method and Apparatus for Sealing and Structurally Renewing a Wall of a Manhole

Abstract

An apparatus and method is provided for structurally renewing and sealing a wall of a manhole. The apparatus includes a tubular sleeve impregnated with a hydrophilic or hydrophobic material capable of expanding when in contact with water, and a liner impregnated with a resinous material capable of curing and hardening. The apparatus is positioned in a manhole and inflated, which forces the tubular sleeve and the liner into contact with the wall of the manhole. The hydrophilic or hydrophobic material is forced into defects of the wall, thus sealing the wall, while the liner is allowed to cure and harden, thus structurally renewing the wall of the manhole.

Claims

1. A liner assembly for sealing and structurally renewing a wall of a manhole, comprising: a liner impregnated with a resinous material capable of curing and hardening; and a tubular sleeve impregnated with a hydrophilic or hydrophobic material capable of curing and hardening, and the material expanding in the presence of water.

2. The liner assembly of claim 1 wherein the liner further comprises a resin absorbent material.

3. The liner assembly of claim 1 wherein the hydrophilic material has a reaction time of under 20 minutes after contact with water.

4. The liner assembly of claim 3 wherein the hydrophobic material expands into flexible foam up to 6 times its original volume.

5. The liner assembly of claim 1 wherein the manhole has a full depth and the tubular sleeve has a length of the full manhole depth.

6. The liner assembly of claim 1 wherein the tubular sleeve is inverted into the manhole.

7. The liner assembly of claim 6 wherein the liner is inverted into the tubular sleeve.

8. The liner assembly of claim 1 wherein the tubular sleeve has a constant unstretched diameter along its length, and is capable of stretching circumferentially to varying diameters for contact with the manhole along the varying diameters.

9. A liner assembly for sealing and structurally renewing a wall of a manhole, comprising: a tubular sleeve impregnated with a hydrophilic or hydrophobic material capable of curing and hardening, and the material expanding in the presence of water; a liner positioned within the tubular sleeve such that the liner and the tubular sleeve are substantially contiguous, said liner impregnated with a resinous material capable of curing and hardening.

10. The liner assembly of claim 9 wherein the liner further comprises a resin absorbent material.

11. The liner assembly of claim 9 wherein the hydrophilic material has a reaction time of under 20 minutes after contact with water.

12. The liner assembly of claim 11 wherein the hydrophobic material expands into flexible foam up to 6 times its original volume.

13. The liner assembly of claim 9 wherein the manhole has a full depth and the tubular sleeve has a length of the full manhole depth.

14. The liner assembly of claim 9 wherein the tubular sleeve is inverted into the manhole.

15. The liner assembly of claim 14 wherein the liner is inverted into the tubular sleeve.

16. The liner assembly of claim 9 wherein the tubular sleeve has a constant unstretched diameter along its length, and is capable of stretching circumferentially to varying diameters for contact with the manhole along the varying diameters.

17. A liner/bladder assembly for sealing and structurally renewing the wall of a manhole, comprising: a tubular sleeve impregnated with a hydrophilic or hydrophobic material capable of expanding when in contact with water; a liner impregnated with a resinous material capable of curing and hardening, wherein the liner is positioned within the tubular sleeve such that the liner and the tubular sleeve are substantially contiguous; and a bladder, the bladder comprising a first end and an opposite closed second end, wherein the bladder is positioned within the liner.

18. The liner/bladder assembly of claim 17 wherein the tubular sleeve comprises a first open end, an opposite second open end, and a sleeve body there between.

19. The liner/bladder assembly of claim 18 wherein the tubular sleeve further comprises an open cell foam material.

20. The liner/bladder assembly of claim 19 wherein an interior surface of the tubular liner is coated with an impermeable polymer film

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] FIG. 1 is a sectional view of a manhole with defects in a wall of the manhole, before the repair method and apparatus of the present invention is used.

[0022] FIG. 2 is a sectional view of a manhole with defects in a wall of the manhole, showing one embodiment of the present invention.

[0023] FIG. 3 is a sectional view similar to FIG. 2, but showing the embodiment in an inflated position.

[0024] FIG. 4 is a sectional view similar to FIG. 3, showing an additional view of the embodiment of the present invention.

[0025] FIG. 5 is a sectional view according to line 5-5 of FIG. 4.

[0026] FIG. 6 is a sectional view of a manhole with defects in a wall of the manhole, showing an additional embodiment of the present invention.

[0027] FIG. 7 is a sectional view similar to FIG. 6, but showing the embodiment in an inflated position.

[0028] FIG. 8 is a sectional view of a manhole that has been repaired using the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] A typical manhole 10 has a bottom pad 12 that has a run through 14. The bottom pad 12 is attached to a barrel 16, a cone section 18, and a plurality of adjusting rings 20. A casting frame 22 is mounted at the upper end of the manhole 10. On top of the casting frame 22 sits a lid 21. As can be seen in FIG. 1, the manhole 10 has a number of diameters D1, D2, D3, and D4. The manhole wall 24 is usually formed of brick, and the bricks can become spaced from one another. In addition, defects 26, such as cracks, holes, or other problems, may form in the wall 24 of the manhole 10.

[0030] FIG. 1 shows a sectional view of a typical manhole 10, showing defects 26 that may occur in a wall 24 of the manhole 10. As the figure shows, the defects 26 may occur in, but are not limited to, the manhole cone 18. Also shown in FIG. 1, ground water 68 can be found outside of the manhole 10. The ground water 68 may seep into the defects 26 of the manhole wall 24, which could further weaken the wall and could potentially cause a collapse of the manhole 10.

[0031] FIG. 2 is a sectional view of the manhole 10 of FIG. 1, but including one exemplary embodiment of the present invention. The manhole lid 21 which is level with the pavement 29 has been removed from the manhole 10. In this embodiment, a liner assembly 30 is provided. The liner assembly 30 includes a tubular sleeve 32 and a liner 34. The tubular sleeve 32 may be made of a resin impregnable material such as open cell super soft foam. It should be noted that the tubular sleeve 32 preferably is used as a carrier to transport an expandable liquid grout material to the manhole wall, and that all or nearly all (approximately 100%) of the material leaves the tubular sleeve 32 when pressed against the wall, leaving the sleeve with minimal thickness. This is illustrated in FIGS. 3-5, where the tubular sleeve 32 has been compressed to minimal thickness with the grout material having penetrated through the defects 26 in the wall 24 of the manhole 10 and to an area in the soil surrounding the manhole 10.

[0032] The tubular sleeve 32 is impregnated with either a hydrophilic or hydrophobic material capable of curing and hardening. In a preferred embodiment, a liquid hydrophobic material is used. The preferred hydrophobic material is a 2-part hydrophobic urethane thermoset resin. When parts A and B are mixed, the combination will begin to cure and harden, but will not expand into a foam material unless it comes into contact with water. One example of a suitable hydrophobic material is THR2, manufactured by Avanti International of 822 Bay Star Blvd., Webster, Tex. 77598, but other manufacturers and model numbers may be used. Hydrophobic grout materials may start to react and expand into a foam material within 20 minutes after contact with water, and can expand up to approximately 6 times their original volume. Once expanded, the hydrophobic grout or foam material will remain expanded and will continue to repel all water, whereas hydrophilic grouts require water to sustain their expanded properties.

[0033] In another embodiment of the invention, the tubular sleeve 32 is impregnated with a liquid hydrophilic material. The hydrophilic material is a one part formulation, which will not react unless in the presence of water. In the presence of water, the hydrophilic material will expand into a foam-like material, sealing water from the interior of a pipe juncture. One example of a suitable hydrophilic material is AV202 manufactured by Avanti International of 822 Bay Star Blvd., Webster, Tex. 77598, but other manufacturers and model numbers may be used. Once activated, the hydrophilic foam material will expand in volume up to approximately eight times its original volume. The hydrophilic foam material will remain flexible and resilient after full cure and will allow movement to occur in the structure without damaging the seal or bond. However, the hydrophilic foam material may shrink after cure in the absence of water.

[0034] A first end 44 of the tubular sleeve 32 and an open end 38 of the liner 34 may be connected to a flange or upper rack 28 and positioned in the manhole 10. The tubular sleeve 32 and the liner 34 may be inverted through the upper rack 28, but it will be appreciated that other positioning methods will work as well. In a preferred embodiment, the second end 46 of the tubular sleeve 32 and the second end 40 of the liner 34 reach a depth equal to the full depth of the manhole 10. Other lengths and depths can be used depending on the damage and configuration of the manhole 10. Connected to the flange 28 is a post 60 with a telescoping pole section 62. The post 60 is connected at the lower end of the manhole 10 to a lower rack 58. The post 60 may be connected to the lower rack 58 by a threaded member 63 of the post 60. A pin 64 located in the post 60 sets the proper length needed for the manhole 10. Also included in the flange 28 is an air inlet tube 66.

[0035] As an alternative to using the tubular sleeve 32 as a carrier to transport an expandable liquid grout material to the manhole wall, the material may also be applied directly to the wall of the manhole using a spin casting device, as is known in the art. The liner 34 is then inflated to force the grout material into the defects 26 of the wall 24 of the manhole. A bladder may or may not be used to inflate the liner 34, depending on whether the liner 34 includes an impermeable coating.

[0036] Referring to FIG. 3, the manhole 10 of FIG. 2 is shown, but with the liner assembly 30 fully inflated. A fluid, preferably air, is provided through the air inlet tube 66 through the flange 28 and into the cavity 36 of the liner 34. The air causes the liner to expand, pressing both the tubular sleeve 32 and the liner 34 against the wall 24 of the manhole 10. The hydrophobic material of the tubular sleeve 32 is forced from the tubular sleeve 32 and into the defects 26 of the manhole wall 24. As described above, the two part hydrophobic material will begin to cure and harden when mixed, but will not expand unless in the presence of water. However, ground water 68 may seep through the soil towards the defects 26 in the walls of the manhole 10, as seen in FIGS. 1 and 2. When the ground water 68 interacts with the hydrophobic material, the hydrophobic material expands both in the soil around the defects 26 and in the cracks, holes, and other defects themselves. FIG. 3 shows the area adjacent the defects 26 of the manhole 10 after the hydrophobic material has been forced through the defects 26 of the manhole 10 and has been introduced to the presence of water (i.e., ground water 68). The hydrophobic material will expand to form a hydrophobic foam 45. The hydrophobic foam 45 cures to create a barrier to keep water from penetrating through the defects 26 of the manhole 10. The inflation is maintained until resinous material impregnated in the liner 34 is allowed to cure and harden. The hardened liner 34 structurally renews the wall 24 of the manhole 10.

[0037] FIG. 4 shows a sectional view of the manhole 10 of FIG. 3 after the hydrophobic material of the tubular sleeve 32 has sealed the wall 24 of the manhole 10, and the liner 34 has been allowed to cure and harden to form a new wall of the manhole 10. The flange 28 and post 60 are removed from the liner assembly 30. However, the closed end 40 of the liner 34, as well as the lower rack 58, must be removed from the lower depth of the manhole 10. The removal may be done by cutting the closed end 40 of the liner 34 out of the manhole 10. The process can be done without having to enter the manhole 10. A knife 72, connected to a handle 70 is inserted into the manhole 10 to cut out and remove the closed end 40 of the liner 34. Note that in cases where liner 34 is closed off like a balloon at the floor, there is no need for the post 60 and lower rack 58.

[0038] The removal of the closed end 40 of the liner 34 is shown in FIG. 5, which is a sectional view according to the line 5-5 of FIG. 4. The knife 72 creates a circular cutout 74 in the closed end 40 of the liner 34 to allow access to the bottom paddle 12 and run through 14 of the manhole 10. However the tubular sleeve 32 is left alone.

[0039] When a liquid hydrophilic material is used to impregnate the tubular sleeve 32, an impermeable barrier (not shown) may also be used. The barrier would be placed between the tubular sleeve 32 and the liner 34. When the hydrophilic material is pressed through the defects 26 and into the soil around the manhole 10, it will not react or cure unless introduced to the presence of water, i.e. ground water 68. Water will cause the hydrophilic material to expand, but also to cure to a flexible material. In the absence of water, the hydrophilic material may shrink, which could cause damage to the cured liner 34. The impermeable, rigid barrier (not shown) will ensure that the liner 34 remains rigid, thus repairing the manhole wall 24.

[0040] Now referring to FIG. 8, a manhole that has been sealed and structurally renewed by the first exemplary embodiment of the present invention is provided. As can be seen, the tubular sleeve 32 and the liner 34 are left in the manhole 10. The hydrophobic grout of the tubular sleeve has seeped into all cracks, defects, holes, and joints, to seal the wall 24 of the manhole 10 from ground water 68. The liner 34 creates a new wall in the manhole 10. After the closed end 40 of the liner 34 is removed, access is still provided to the bottom paddle 12 and the run through 14 of the manhole 10. All other components of the liner assembly 30 are removed and the manhole lid 21 is replaced on top of the casting frame 22 which creates a flat surface with the pavement 29 around the manhole 10.

[0041] FIGS. 6 and 7 show yet another exemplary embodiment of the present invention. FIG. 6 shows the same manhole 10 of FIG. 1 with defects 26 that may allow ground water 68 to seep through the wall 24 of the manhole 10, thus creating structural problems in the manhole 10. In this particular embodiment, a liner/bladder assembly 50 is provided. The assembly 50 includes a tubular sleeve 32, a liner 34, and a bladder 52. The tubular sleeve is made of resin impregnable material as stated above, and is impregnated with a hydrophobic or hydrophilic material capable of curing and hardening and expanding in the presence of water. The liner 34 is made of a resinous absorbable material, and is impregnated with a resinous material capable of curing and hardening. The liner/bladder assembly 50 is positioned in the manhole 10 with the tubular sleeve 32 nearest the manhole wall 24, the liner 34 abutted against an interior surface 42 of the tubular sleeve 32, and a bladder 52 inserted within the liner 34. The upper end 54 of the bladder 52 may be connected to a flange 28, which includes an air inlet tube 66, and which rests on the casting frame 22 of the manhole 10. The lower end 56 of the bladder 52 may be connected to a lower rack 58, which includes a hook 65 and a rope 67. Air, or another fluid, is put through the air inlet tube 66, which inflates the liner/bladder assembly 50. The bladder 52 is inflated to press the tubular sleeve 32 and the liner 34 against the wall 24 of the manhole 10. When the tubular sleeve 32 is pressed against the wall 24 of the manhole 10, the hydrophobic or hydrophilic material of the tubular sleeve 32 is forced into the defects 26 of said wall 24. The hydrophobic or hydrophilic material may come in contact with ground water 68, causing the material to expand and cure, thus sealing the wall 24 of the manhole 10 from future water damage. The bladder 52 is inflated until the resinous material of the liner 34 is allowed to cure and harden. The cured and hardened liner structurally renews the wall 24 of the manhole 10. Once the liner has cured, air may be released from the bladder 52, and the rope 67 pulls the lower end 56 of the bladder 52, which is connected to the lower rack 58 to remove the bladder. Once the bladder is removed, what is left is a sealed and structurally renewed manhole, as can be seen in FIG. 8.

[0042] The invention has been shown and described above with reference to the preferred embodiments, and it is understood that many modifications, substitutions, and additions may be made which are within the intended spirit and scope of the invention. The invention is only to be limited by claims appended hereto.