CA2204716A1 - Pre-cast manhole basin and method and apparatus for connecting a pipe thereto - Google Patents
Pre-cast manhole basin and method and apparatus for connecting a pipe theretoInfo
- Publication number
- CA2204716A1 CA2204716A1 CA 2204716 CA2204716A CA2204716A1 CA 2204716 A1 CA2204716 A1 CA 2204716A1 CA 2204716 CA2204716 CA 2204716 CA 2204716 A CA2204716 A CA 2204716A CA 2204716 A1 CA2204716 A1 CA 2204716A1
- Authority
- CA
- Canada
- Prior art keywords
- connector
- opening
- pipe
- collars
- sidewall
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
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Classifications
-
- E—FIXED CONSTRUCTIONS
- E03—WATER SUPPLY; SEWERAGE
- E03F—SEWERS; CESSPOOLS
- E03F5/00—Sewerage structures
- E03F5/02—Manhole shafts or other inspection chambers; Snow-filling openings; accessories
- E03F5/021—Connection of sewer pipes to manhole shaft
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D29/00—Independent underground or underwater structures; Retaining walls
- E02D29/12—Manhole shafts; Other inspection or access chambers; Accessories therefor
- E02D29/14—Covers for manholes or the like; Frames for covers
- E02D29/1463—Hinged connection of cover to frame
-
- E—FIXED CONSTRUCTIONS
- E03—WATER SUPPLY; SEWERAGE
- E03F—SEWERS; CESSPOOLS
- E03F5/00—Sewerage structures
- E03F5/02—Manhole shafts or other inspection chambers; Snow-filling openings; accessories
Landscapes
- Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Health & Medical Sciences (AREA)
- Hydrology & Water Resources (AREA)
- Public Health (AREA)
- Water Supply & Treatment (AREA)
- Environmental & Geological Engineering (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Mining & Mineral Resources (AREA)
- Paleontology (AREA)
- Civil Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Structural Engineering (AREA)
- Underground Structures, Protecting, Testing And Restoring Foundations (AREA)
Abstract
A method for connecting the a precast manhole base section to at least one pipe, in which the base section has a sidewall opening. The base section is positioned in a trench, and a connector has its inner end portion fitted into the opening. The pipe is connected to the outer end of the connector and is axially aligned with the connector by adjustment of the position of the connector in the opening, the opening having a clearance space around the connector.
Collars are fitted around the connector and are clamped against the inside and outside of the sidewall around the opening, and inner rims of the collars are sealed around the connector so that the collars define an annular chamber between the connector and the periphery of the opening.
Finally settable material is admitted into the chamber to seal the connector to the sidewall.
Collars are fitted around the connector and are clamped against the inside and outside of the sidewall around the opening, and inner rims of the collars are sealed around the connector so that the collars define an annular chamber between the connector and the periphery of the opening.
Finally settable material is admitted into the chamber to seal the connector to the sidewall.
Description
CA 02204716 1997-0~-06 TITLE: Pre-Cast Manhole Basin and Method and Apparatus for Connecting a Pipe Thereto.
BACKGROUND OF THE INVENTION.
1. FIELD OF THE INVENTION
The present invention relates to pre-cast manhole basins or casements for use in sewer systems and as catchment basins.
The sewer manhole basin normally has both an inlet connected 10 to an inlet pipe section, and an outlet connected to an outlet pipe section. A catchment basin may have only an inlet.
BACKGROUND OF THE INVENTION.
1. FIELD OF THE INVENTION
The present invention relates to pre-cast manhole basins or casements for use in sewer systems and as catchment basins.
The sewer manhole basin normally has both an inlet connected 10 to an inlet pipe section, and an outlet connected to an outlet pipe section. A catchment basin may have only an inlet.
2. PRIOR ART
In the past, it was the practice to position inlet and 15 outlet pipes in a trench on each side of an opening suitable for a manhole, and to form the base section of the manhole basin by casting concrete in situ around the pipe ends. It has also been known to precast the base section of the manhole basin with openings for receiving the pipe ends, to position 20 the base section with the ends of the pipes received in the openings, and to apply concrete or suitable grout to secure and seal the pipes to the walls of the manhole base section.
A problem with either of these procedures is that movement of one of the pipes relative to the manhole base section, perhaps 25 resulting from backfilling of the trench or settling of the earth beneath the pipe, causes cracking of the joint with the manhole base section and consequent leakage.
In accordance with my prior Canadian Patent No.730,501, issued Mar.22, 1966, a precast manhole base section is 30 provided which includes various arrangements of spigots and bell ends as part of the precast section, and these spigots and bell ends are connected to adjacent pipe sections by flexible seals which allow for some settling of the pipes without causing leakage.
The flexible seals provided in accordance with the '501 patent, as well as allowing some settling, also allow for minor misalignment between the inlet and outlet pipe sections and the axes of the spigots and bell ends which are cast into CA 02204716 1997-0~-06 the manhole basin section. However, the fact that the precast spigot and bell end, which are fixed, have to be quite well aligned with the inlet and outlet pipes, which often vary in orientation, is a drawback. The amount of misalignment which 5 can be tolerated using this prior arrangement is rather limited, and when the pipes have been installed the range of movement provided by the flexible seal may be used up even before any settlement has occurred. Accordingly, there is a need to provide a manhole basin system which will allow for 10 a greater variation in the relative orientation of the inlet and outlet pipe sections.
The prior art also includes some proposals for special flexible seals to be used between pipes and a manhole basin;
as for example in U.S. Pat.No.4,993,722, issued Feb.19,1991 15 to Gundy. However, such proposals have the drawback of requiring special, relatively expensive equipment. The present invention, by contrast, makes use of cement or similar grout which is always easily available.
A further problem with prior art manhole basins is that 20 settlement of the manhole basin can cause lowering of the manhole cover relative to grade level, resulting in a "pothole". This problem is especially acute in cold climates since the manhole sump or base section extends below the frost line and is relatively stable, while the frost causes the 25 ground around the upper sections of the manhole basin to heave and rise. Even when the frost has gone, the manhole cover will usually remain sunken. A further object of this invention is to alleviate this problem.
According to one aspect of the invention, there is provided a method of installing and connecting together the base section of a manhole basin and at least one pipe, wherein the base section is precast and has a sidewall with an 35 opening, the method comprising the steps of:
a) positioning said base section in a trench with the opening directed along the length of the trench, CA 02204716 1997-0~-06 b) providing a pipe connector having one end portion sized to fit into the opening, the connector end portion and opening being dimensioned so that the opening has substantial clearance around the connector, the connector having an 5 opposite end portion configured to connect to an end of the pipe;
c) inserting the one end portion of the connector into the opening, d) installing the pipe in the trench and attaching said 10 end of the pipe to said opposite end portion of the connector by means of a flexible coupling;
e) supporting the connector substantially axially aligned with the pipe and with clearance between the connector and the periphery of the opening;
15f) mounting a first annular collar around the connector and against the inside of said sidewall around said periphery;
g) mounting a second annular collar around the connector and against the outside of said sidewall around said periphery;
20h) sealingly securing respective inner rims of the collars around the connector;
i) securing each of the collars to respective inner and outer surfaces of said sidewall to surround a major portion of the periphery of the opening, leaving an entrance hole, the 25 collars defining an annular chamber between the connector and the periphery of said opening; and j) admitting settable material into the chamber by way of the entrance hole to seal the connector to the sidewall.
Each collar may be of flexible sheet material and may be 30 secured to the connector by a drawstring provided around the inner rim, the step of securing said collars then including the steps of positioning the collars and tightening the drawstrings to bring the sheet material into contact with the exterior surface of the connector.
35The collars may be secured to the base section sidewall by clamping means, for example using annular flanges and bolts which pass through the collars and the opening. Holes may be provided in the flexible sheet material to receive the bolts.
CA 02204716 1997-0~-06 Alternatively, the holes may be formed by pushing the bolts through the material.
According to another aspect of the invention, there is provided apparatus in the form of a kit of parts including the 5 annular collars with the drawstrings to hold their inner rims around the connector, and the flanges which hold the collars in place against the inner and outer sidewall surfaces of the basin, leaving an inlet opening for the grouting material.
To correct misalignment problems, the diameter of the 10 opening in the base section, which will normally be approximately circular, must be substantially larger than the diameter of that part of the connector which fits inside it, and which will normally be the same diameter as the main pipe sections between their spigots and bells. Preferably, the 15 clearance space between the connector and the opening will allow the connector to be off-set at least 10~, and preferably at least 15~, from the axis of the opening, which axis will normally be radial to the cylindrical manhole base section.
When it is part of a sewer system, the manhole basin 20 section will be precast with a spigot for receiving the end of an outlet pipe, and the connector will be provided with a bell end, positioned outside the opening, for receiving the spigot end of an inlet pipe. The outlet pipe will largely be in position in a trench when the manhole basin section is 25 being positioned, and the base section will have its outlet spigot connected to the outlet pipe during positioning of the base section. The size of the opening which receives the connector allows for reasonable variation in the relative orientations of the inlet and outlet pipes.
The manhole base section with the opening is usually the lowermost of several precast sections. Normally, several further sections, of generally cylindrical shape, are fitted on top of this base section to build up the manhole basin to the grade level. As mentioned, in known arrangements, in 35 which the basin is invariable in height, the whole basin may become sunken relative to the grade level, due to frost heaving.
CA 02204716 1997-0~-06 To alleviate this problem, in accordance with another aspect of this invention, there is provided a manhole basin or casement having a topmost section and a co-axial subjacent section, wherein the topmost section is supported on the 5 subjacent section but is movable telescopically relative to the subjacent section, the topmost section having an upper portion with an opening to receive the manhole cover and having an exterior surface with an enlargement. The enlargement of topmost section allows this section to rise 10 with the upper layers of earth when these are raised by frost or other effects.
Preferably, the enlargement is provided by forming the topmost section with a lower portion which diverges upwardly and outwardly, the upper portion of this section converging 15 towards the manhole cover. The lower portion preferably has a height significantly longer than the height of the upper portion so that the maximum diameter of the enlargement is fairly close to the top of the topmost section.
20 BRIEF DESCRIPTION OF THE DRAWINGS.
Preferred embodiments of the invention will now be described by way of example with reference to the accompanying drawings, in which;
Figure 1 is a perspective, exploded, view of the base 25 section of a manhole basin or casement installation, and associated parts, in accordance with the invention;
Figures 2, 3 and 4 are sectional elevations through a sidewall of the manhole basin showing successive stages in the installation of a connector;
Figure 5 is an inside end view of the connector, during sealing of the connector to the basin section, taken on lines 5-5 of Figure 4;
Figure 6 is a detail sectional view of the upper portion of the installed connector taken on its centre line;
Figure 7 is a detail sectional view of the lower portion of the installed connector taken on its centre line; and CA 02204716 1997-0~-06 Figure 8 is a sectional elevation of a top portion of a manhole basin in accordance with another aspect of the invention.
5 DETAILED DESCRIPTION.
Figure 1 shows the base section 10 of the precast manhole basin or casement, having a cylindrical sidewall 10a, and formed with an integral spigot 12 suitable for fitting onto the bell end of an outlet sewer pipe. At about the same 10 level, and disposed at about a right angle around the basin axis, the sidewall has an opening 14 which is roughly circular and has a diameter rather larger than that of the spigot 12.
Generally, the opening will be sized to have a diameter about 15 10% to 20% larger than the outer diameter of the main sections of pipes used in the sewer system, i.e the diameters of the sections measured between their bell and spigot ends. The opening is sized to loosely receive a pipe connector 16 having a main cylindrical portion and a bell end 16a; this connector 20 may be a short piece of the sewer pipe cut off close to its bell end.
The manhole basin section so far described is placed in a trench, enlarged as necessary, in which at least the main section of outlet pipe has already been laid. The basin is 25 preferably laid on bedding similar to that used for the pipes, in accordance with my previous '501 patent referred to above.
The outlet pipe is then connected onto the spigot 12 with a flexible seal, also in accordance with my previous patent.
Naturally, the orientation of the basin will be chosen to 30 align the spigot with the outlet pipe, which is customarily laid before the inlet pipe.
With these parts in position, the connector 16 is inserted into the opening 14 as illustrated in Figure 2. As shown, before the connector is inserted, it is preferably 35 provided with an encircling collar 20, formed of flexible plastic material such as nylon or polyethylene, and an annular rigid flange 22, preferably of metal, abutting the outer side of the collar. The collar 20 is generally of annular form, CA 02204716 1997-0~-06 having an outer diameter considerably larger than that of the opening 14, and having an inner rim which fits onto the main portion of the connector and is provided with a drawstring 21 for tightening it around the connector. The flange 22 is 5 provided at its top with a gap subtending about 10 to 15~ at the flange center. The inner end of the connector is pushed through the opening to protrude on the inside of the sidewall, where it is provided with a similar combination of collar 20' with drawstring 21', and metal flange 22', as shown in Figure 10 3. With these parts in position, the outer bell end of the connector is fitted onto an inlet pipe section, indicated in Figure 4 at P, which is orientated along its trench; a flexible gasket G provides a seal. The clearance space between the periphery of the opening, meaning its inward 15 facing surface, and the cylindrical main portion of the connector, allows the connector to be aligned with the main pipe axis even if this is not aligned with the axis of the opening. When suitable alignment has been achieved small stones can be packed around the connector to hold it 20 temporarily in position.
Once the connector has been positioned, it can be sealed and secured to the sidewall with cement, using the collars 20 and 20', drawstrings 21 and 21', and flanges 22 and 22'. For this purpose the drawstrings are tightened around the 25 connector, and the flanges 22 and 22' are joined by bolts 24 which pass through the opening 14 adjacent to its periphery and also pass through holes in the flanges and collars. Nuts are applied to the bolts 24 and tightened so that the flanges seal the collars to the sidewalls, except in the regions of 30 their gaps, where bulges 20a and 20'a in the collars provide inlets and outlets into the otherwise sealed annular chamber between the connector and the periphery of the opening.
Cement or other suitable grouting material is then inserted into the inlet, which is conveniently that formed by the bulge 35 20a on the outside of the sidewall, while air is expelled from the outlet on the other side. Accordingly when the grouting material has set, the connector is sealed and secured to the sidewall while properly aligned with the inlet pipe.
CA 02204716 1997-0~-06 An advantage of this system over others of which I am aware is that the fixing of the connector into the base section can be done while workers continue to lay the inlet pipe, so that pipe laying is not delayed.
Figure 8 shows a further feature of this invention, in relation to the upper part of the manhole basin. As shown, a middle section 30 of the basin, which is subjacent to the topmost section 32, is connected to this top section by a telescopic joint provided by a sealing ring 34 held in an 10 external groove 36 close to the upper end of section 30, which mates with a cylindrical recess 38 in the lower end of upper section 32. An annular metal rim 40 mounted onto the top of section 32 has an opening 42 for a manhole cover 44. Section 32 has a lower portion which diverges upwardly and outwardly 15 at an angle of between 5 and 10~, and which occupies about 70-80% of its height, and an upper portion which converges from the top of the lower portion to the top of the basin. This provides an enlargement which allows the topmost section to be raised by the ground when this is caused to rise due to 20 frost heave, while the telescopic joint maintains sealed connection with the stationary subjacent section.
Accordingly, the top of the basin tends to remain at the grade level.
In the past, it was the practice to position inlet and 15 outlet pipes in a trench on each side of an opening suitable for a manhole, and to form the base section of the manhole basin by casting concrete in situ around the pipe ends. It has also been known to precast the base section of the manhole basin with openings for receiving the pipe ends, to position 20 the base section with the ends of the pipes received in the openings, and to apply concrete or suitable grout to secure and seal the pipes to the walls of the manhole base section.
A problem with either of these procedures is that movement of one of the pipes relative to the manhole base section, perhaps 25 resulting from backfilling of the trench or settling of the earth beneath the pipe, causes cracking of the joint with the manhole base section and consequent leakage.
In accordance with my prior Canadian Patent No.730,501, issued Mar.22, 1966, a precast manhole base section is 30 provided which includes various arrangements of spigots and bell ends as part of the precast section, and these spigots and bell ends are connected to adjacent pipe sections by flexible seals which allow for some settling of the pipes without causing leakage.
The flexible seals provided in accordance with the '501 patent, as well as allowing some settling, also allow for minor misalignment between the inlet and outlet pipe sections and the axes of the spigots and bell ends which are cast into CA 02204716 1997-0~-06 the manhole basin section. However, the fact that the precast spigot and bell end, which are fixed, have to be quite well aligned with the inlet and outlet pipes, which often vary in orientation, is a drawback. The amount of misalignment which 5 can be tolerated using this prior arrangement is rather limited, and when the pipes have been installed the range of movement provided by the flexible seal may be used up even before any settlement has occurred. Accordingly, there is a need to provide a manhole basin system which will allow for 10 a greater variation in the relative orientation of the inlet and outlet pipe sections.
The prior art also includes some proposals for special flexible seals to be used between pipes and a manhole basin;
as for example in U.S. Pat.No.4,993,722, issued Feb.19,1991 15 to Gundy. However, such proposals have the drawback of requiring special, relatively expensive equipment. The present invention, by contrast, makes use of cement or similar grout which is always easily available.
A further problem with prior art manhole basins is that 20 settlement of the manhole basin can cause lowering of the manhole cover relative to grade level, resulting in a "pothole". This problem is especially acute in cold climates since the manhole sump or base section extends below the frost line and is relatively stable, while the frost causes the 25 ground around the upper sections of the manhole basin to heave and rise. Even when the frost has gone, the manhole cover will usually remain sunken. A further object of this invention is to alleviate this problem.
According to one aspect of the invention, there is provided a method of installing and connecting together the base section of a manhole basin and at least one pipe, wherein the base section is precast and has a sidewall with an 35 opening, the method comprising the steps of:
a) positioning said base section in a trench with the opening directed along the length of the trench, CA 02204716 1997-0~-06 b) providing a pipe connector having one end portion sized to fit into the opening, the connector end portion and opening being dimensioned so that the opening has substantial clearance around the connector, the connector having an 5 opposite end portion configured to connect to an end of the pipe;
c) inserting the one end portion of the connector into the opening, d) installing the pipe in the trench and attaching said 10 end of the pipe to said opposite end portion of the connector by means of a flexible coupling;
e) supporting the connector substantially axially aligned with the pipe and with clearance between the connector and the periphery of the opening;
15f) mounting a first annular collar around the connector and against the inside of said sidewall around said periphery;
g) mounting a second annular collar around the connector and against the outside of said sidewall around said periphery;
20h) sealingly securing respective inner rims of the collars around the connector;
i) securing each of the collars to respective inner and outer surfaces of said sidewall to surround a major portion of the periphery of the opening, leaving an entrance hole, the 25 collars defining an annular chamber between the connector and the periphery of said opening; and j) admitting settable material into the chamber by way of the entrance hole to seal the connector to the sidewall.
Each collar may be of flexible sheet material and may be 30 secured to the connector by a drawstring provided around the inner rim, the step of securing said collars then including the steps of positioning the collars and tightening the drawstrings to bring the sheet material into contact with the exterior surface of the connector.
35The collars may be secured to the base section sidewall by clamping means, for example using annular flanges and bolts which pass through the collars and the opening. Holes may be provided in the flexible sheet material to receive the bolts.
CA 02204716 1997-0~-06 Alternatively, the holes may be formed by pushing the bolts through the material.
According to another aspect of the invention, there is provided apparatus in the form of a kit of parts including the 5 annular collars with the drawstrings to hold their inner rims around the connector, and the flanges which hold the collars in place against the inner and outer sidewall surfaces of the basin, leaving an inlet opening for the grouting material.
To correct misalignment problems, the diameter of the 10 opening in the base section, which will normally be approximately circular, must be substantially larger than the diameter of that part of the connector which fits inside it, and which will normally be the same diameter as the main pipe sections between their spigots and bells. Preferably, the 15 clearance space between the connector and the opening will allow the connector to be off-set at least 10~, and preferably at least 15~, from the axis of the opening, which axis will normally be radial to the cylindrical manhole base section.
When it is part of a sewer system, the manhole basin 20 section will be precast with a spigot for receiving the end of an outlet pipe, and the connector will be provided with a bell end, positioned outside the opening, for receiving the spigot end of an inlet pipe. The outlet pipe will largely be in position in a trench when the manhole basin section is 25 being positioned, and the base section will have its outlet spigot connected to the outlet pipe during positioning of the base section. The size of the opening which receives the connector allows for reasonable variation in the relative orientations of the inlet and outlet pipes.
The manhole base section with the opening is usually the lowermost of several precast sections. Normally, several further sections, of generally cylindrical shape, are fitted on top of this base section to build up the manhole basin to the grade level. As mentioned, in known arrangements, in 35 which the basin is invariable in height, the whole basin may become sunken relative to the grade level, due to frost heaving.
CA 02204716 1997-0~-06 To alleviate this problem, in accordance with another aspect of this invention, there is provided a manhole basin or casement having a topmost section and a co-axial subjacent section, wherein the topmost section is supported on the 5 subjacent section but is movable telescopically relative to the subjacent section, the topmost section having an upper portion with an opening to receive the manhole cover and having an exterior surface with an enlargement. The enlargement of topmost section allows this section to rise 10 with the upper layers of earth when these are raised by frost or other effects.
Preferably, the enlargement is provided by forming the topmost section with a lower portion which diverges upwardly and outwardly, the upper portion of this section converging 15 towards the manhole cover. The lower portion preferably has a height significantly longer than the height of the upper portion so that the maximum diameter of the enlargement is fairly close to the top of the topmost section.
20 BRIEF DESCRIPTION OF THE DRAWINGS.
Preferred embodiments of the invention will now be described by way of example with reference to the accompanying drawings, in which;
Figure 1 is a perspective, exploded, view of the base 25 section of a manhole basin or casement installation, and associated parts, in accordance with the invention;
Figures 2, 3 and 4 are sectional elevations through a sidewall of the manhole basin showing successive stages in the installation of a connector;
Figure 5 is an inside end view of the connector, during sealing of the connector to the basin section, taken on lines 5-5 of Figure 4;
Figure 6 is a detail sectional view of the upper portion of the installed connector taken on its centre line;
Figure 7 is a detail sectional view of the lower portion of the installed connector taken on its centre line; and CA 02204716 1997-0~-06 Figure 8 is a sectional elevation of a top portion of a manhole basin in accordance with another aspect of the invention.
5 DETAILED DESCRIPTION.
Figure 1 shows the base section 10 of the precast manhole basin or casement, having a cylindrical sidewall 10a, and formed with an integral spigot 12 suitable for fitting onto the bell end of an outlet sewer pipe. At about the same 10 level, and disposed at about a right angle around the basin axis, the sidewall has an opening 14 which is roughly circular and has a diameter rather larger than that of the spigot 12.
Generally, the opening will be sized to have a diameter about 15 10% to 20% larger than the outer diameter of the main sections of pipes used in the sewer system, i.e the diameters of the sections measured between their bell and spigot ends. The opening is sized to loosely receive a pipe connector 16 having a main cylindrical portion and a bell end 16a; this connector 20 may be a short piece of the sewer pipe cut off close to its bell end.
The manhole basin section so far described is placed in a trench, enlarged as necessary, in which at least the main section of outlet pipe has already been laid. The basin is 25 preferably laid on bedding similar to that used for the pipes, in accordance with my previous '501 patent referred to above.
The outlet pipe is then connected onto the spigot 12 with a flexible seal, also in accordance with my previous patent.
Naturally, the orientation of the basin will be chosen to 30 align the spigot with the outlet pipe, which is customarily laid before the inlet pipe.
With these parts in position, the connector 16 is inserted into the opening 14 as illustrated in Figure 2. As shown, before the connector is inserted, it is preferably 35 provided with an encircling collar 20, formed of flexible plastic material such as nylon or polyethylene, and an annular rigid flange 22, preferably of metal, abutting the outer side of the collar. The collar 20 is generally of annular form, CA 02204716 1997-0~-06 having an outer diameter considerably larger than that of the opening 14, and having an inner rim which fits onto the main portion of the connector and is provided with a drawstring 21 for tightening it around the connector. The flange 22 is 5 provided at its top with a gap subtending about 10 to 15~ at the flange center. The inner end of the connector is pushed through the opening to protrude on the inside of the sidewall, where it is provided with a similar combination of collar 20' with drawstring 21', and metal flange 22', as shown in Figure 10 3. With these parts in position, the outer bell end of the connector is fitted onto an inlet pipe section, indicated in Figure 4 at P, which is orientated along its trench; a flexible gasket G provides a seal. The clearance space between the periphery of the opening, meaning its inward 15 facing surface, and the cylindrical main portion of the connector, allows the connector to be aligned with the main pipe axis even if this is not aligned with the axis of the opening. When suitable alignment has been achieved small stones can be packed around the connector to hold it 20 temporarily in position.
Once the connector has been positioned, it can be sealed and secured to the sidewall with cement, using the collars 20 and 20', drawstrings 21 and 21', and flanges 22 and 22'. For this purpose the drawstrings are tightened around the 25 connector, and the flanges 22 and 22' are joined by bolts 24 which pass through the opening 14 adjacent to its periphery and also pass through holes in the flanges and collars. Nuts are applied to the bolts 24 and tightened so that the flanges seal the collars to the sidewalls, except in the regions of 30 their gaps, where bulges 20a and 20'a in the collars provide inlets and outlets into the otherwise sealed annular chamber between the connector and the periphery of the opening.
Cement or other suitable grouting material is then inserted into the inlet, which is conveniently that formed by the bulge 35 20a on the outside of the sidewall, while air is expelled from the outlet on the other side. Accordingly when the grouting material has set, the connector is sealed and secured to the sidewall while properly aligned with the inlet pipe.
CA 02204716 1997-0~-06 An advantage of this system over others of which I am aware is that the fixing of the connector into the base section can be done while workers continue to lay the inlet pipe, so that pipe laying is not delayed.
Figure 8 shows a further feature of this invention, in relation to the upper part of the manhole basin. As shown, a middle section 30 of the basin, which is subjacent to the topmost section 32, is connected to this top section by a telescopic joint provided by a sealing ring 34 held in an 10 external groove 36 close to the upper end of section 30, which mates with a cylindrical recess 38 in the lower end of upper section 32. An annular metal rim 40 mounted onto the top of section 32 has an opening 42 for a manhole cover 44. Section 32 has a lower portion which diverges upwardly and outwardly 15 at an angle of between 5 and 10~, and which occupies about 70-80% of its height, and an upper portion which converges from the top of the lower portion to the top of the basin. This provides an enlargement which allows the topmost section to be raised by the ground when this is caused to rise due to 20 frost heave, while the telescopic joint maintains sealed connection with the stationary subjacent section.
Accordingly, the top of the basin tends to remain at the grade level.
Claims (10)
1. A method of installing and connecting together a base section of a manhole basin and at least one pipe, wherein the base section is precast and has a sidewall with an opening, comprising the steps of:
a) positioning said base section in a trench with the opening directed along the length of the trench, b) providing a pipe connector having one end portion sized to fit into said opening, the connector end portion and opening being dimensioned so that the opening has substantial clearance around the connector, the connector having an opposite end portion configured to connect to an end of the pipe;
c) inserting the one end portion of the connector into said opening, d) installing the pipe in the trench and attaching said end of the pipe to said opposite end portion of the connector by means of a flexible coupling;
e) supporting the connector substantially axially aligned with the pipe and with clearance between the connector and the periphery of the opening;
f) mounting a first annular collar around the connector and against the inside of said sidewall around said periphery;
g) mounting a second annular collar around the connector and against the outside of said sidewall around said periphery;
h) sealingly securing respective inner rims of the collars around the connector;
i) securing each of the collars to respective inner and outer surfaces of said sidewall to surround a major portion of the periphery of the opening, leaving an entrance hole, the collars defining an annular chamber between the connector and the periphery of said opening; and j) admitting settable material into the chamber by way of the entrance hole to seal the connector to the sidewall.
a) positioning said base section in a trench with the opening directed along the length of the trench, b) providing a pipe connector having one end portion sized to fit into said opening, the connector end portion and opening being dimensioned so that the opening has substantial clearance around the connector, the connector having an opposite end portion configured to connect to an end of the pipe;
c) inserting the one end portion of the connector into said opening, d) installing the pipe in the trench and attaching said end of the pipe to said opposite end portion of the connector by means of a flexible coupling;
e) supporting the connector substantially axially aligned with the pipe and with clearance between the connector and the periphery of the opening;
f) mounting a first annular collar around the connector and against the inside of said sidewall around said periphery;
g) mounting a second annular collar around the connector and against the outside of said sidewall around said periphery;
h) sealingly securing respective inner rims of the collars around the connector;
i) securing each of the collars to respective inner and outer surfaces of said sidewall to surround a major portion of the periphery of the opening, leaving an entrance hole, the collars defining an annular chamber between the connector and the periphery of said opening; and j) admitting settable material into the chamber by way of the entrance hole to seal the connector to the sidewall.
2. A method according to claim 1, wherein each collar is of flexible sheet material and is secured to the connector by a drawstring provided around its inner rim, the step of securing said collars including the steps of positioning the collars and tightening the drawstrings to bring the sheet material into contact with the exterior surface of the connector.
3. A method according to claim 1, wherein the collars are secured to inner and outer surfaces of the sidewall by means of annular flanges on outer surfaces of the collars, which flanges are connected together by bolts which pass through said opening.
4. A method according to claim 1, wherein the clearance between the connector and the opening is sufficient to allow the connector to be off-set at least 10° from the axis of the opening, which axis is radial to the base section.
5. A method according to claim 1, wherein the manhole basin is integrally cast with a spigot for connection to an outlet pipe, and wherein said connector has a bell end for connection to an inlet pipe.
6. A kit of parts for use in connecting together the base section of a manhole basin and at least one pipe, said base section having a sidewall with an opening which is larger than the outer diameter of the pipe, said kit comprising a pair of annular collars each having an outer diameter larger than that of said opening and an inner rim with means for sealingly securing the inner rim around a pipe connector which is similar in diameter to the pipe, and a pair of annular flanges having outer diameters larger than that of the opening and inner diameters smaller than that of the opening, and bolt means for clamping the flanges to outer portions of the collars on opposite sides of said sidewall to hold said collars against said sidewall and to create an annular chamber between the connector and the periphery of the opening for grouting material.
7. A kit of parts according to claim 6, further comprising said pipe connector as part of said kit, said connector having a bell end and having a main cylindrical portion suitable for fitting into the opening, and which is similar in diameter to said pipe.
8. A manhole basin having a topmost section and a subjacent section, wherein the topmost section is supported on the subjacent section but is movable telescopically relative to the subjacent section, the topmost section having an upper portion with an opening to receive a manhole cover and having an exterior surface with an enlargement, said enlargement being such as to allow the topmost section to rise with upper layers of earth when these are raised by frost or other effects.
9. A manhole basin according to claim 8, wherein said enlargement is provided by forming the topmost section with a lower portion which diverges upwardly and outwardly, and an upper portion which converges towards the manhole cover.
10. A manhole basin according to claim 9, wherein the lower portion has a height significantly greater than the height of the upper portion.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2204716 CA2204716A1 (en) | 1997-05-06 | 1997-05-06 | Pre-cast manhole basin and method and apparatus for connecting a pipe thereto |
| CA 2208416 CA2208416A1 (en) | 1997-05-06 | 1997-06-20 | Pre-cast manhole basins and catch basins for use in sewer and drainage systems |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2204716 CA2204716A1 (en) | 1997-05-06 | 1997-05-06 | Pre-cast manhole basin and method and apparatus for connecting a pipe thereto |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2204716A1 true CA2204716A1 (en) | 1998-11-06 |
Family
ID=4160599
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2204716 Abandoned CA2204716A1 (en) | 1997-05-06 | 1997-05-06 | Pre-cast manhole basin and method and apparatus for connecting a pipe thereto |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2204716A1 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102296634A (en) * | 2011-06-16 | 2011-12-28 | 天津市泽宝水泥制品有限公司 | Concrete inspection well chamber with flexible interface connection branch |
| CN105133649A (en) * | 2015-08-24 | 2015-12-09 | 泉州市路通管业科技有限公司 | Inspection well capable of performing reliable sealing of branch pipe and production technology of inspection well |
| CN113232152A (en) * | 2021-04-25 | 2021-08-10 | 中国化学工程第三建设有限公司 | Method for prefabricating concrete well chamber |
| CN113775023A (en) * | 2021-09-26 | 2021-12-10 | 陕西建工第十二建设集团有限公司 | Device and method for connecting cast-in-situ rainwater and sewage inspection well chamber with prefabricated concrete pipeline |
-
1997
- 1997-05-06 CA CA 2204716 patent/CA2204716A1/en not_active Abandoned
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102296634A (en) * | 2011-06-16 | 2011-12-28 | 天津市泽宝水泥制品有限公司 | Concrete inspection well chamber with flexible interface connection branch |
| CN105133649A (en) * | 2015-08-24 | 2015-12-09 | 泉州市路通管业科技有限公司 | Inspection well capable of performing reliable sealing of branch pipe and production technology of inspection well |
| CN113232152A (en) * | 2021-04-25 | 2021-08-10 | 中国化学工程第三建设有限公司 | Method for prefabricating concrete well chamber |
| CN113775023A (en) * | 2021-09-26 | 2021-12-10 | 陕西建工第十二建设集团有限公司 | Device and method for connecting cast-in-situ rainwater and sewage inspection well chamber with prefabricated concrete pipeline |
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