GB2203815A

GB2203815A - Internal lining for the restoration of underground sewerage systems

Info

Publication number: GB2203815A
Application number: GB08809400A
Authority: GB
Inventors: Dipl Ing Muthard Weise; Werner Leyh; Martin Eck; Werner Danz
Original assignee: WASSERVERSORGUNG ABWASSE
Current assignee: WASSERVERSORGUNG ABWASSE
Priority date: 1987-04-24
Filing date: 1988-04-21
Publication date: 1988-10-26
Anticipated expiration: 2008-04-21
Also published as: SE8704860L; DD279796A3; FR2614333B1; GB2203815B; HUT47665A; GB8809400D0; FR2614333A1; SE8704860D0; DE3732597A1; HU204318B

Description

SOLID BODY SEGMENT INTERNAL LINING FOR RESTORING UNDERGROUND SEWERAGE SYSTEMS The invention concerns an internal lining for restoring underground sewerage systems of any kind of configuration and material for nominal widths DN 300 - 800.

DD-WP 66571 discloses an inflatable internal lining or sheathing for the restoration of steel or cast iron pipelines in accordance with the pressing-out or extrusion principle.

A prefabricated tube of a length of about 50 m is drawn into the pipe which is to be restored.

The pipe performs the function of the external sheathing while the air-filled tube performs the function of the internal lining or sheathing. The annualr gap required, which corresponds to the new wall thickness to be provided, and the central positioning of the tube lining in the pipe are ensured by a system, arranged around the tube, of spacer members (mesh with concrete elements). The annular gap is filled with å cement suspension by extrusion. After a setting time, the air is let out of the tube lining and the tube is drawn out of the pipe portion.

The cement mortar extrusion process with the associated tube lining, in the present state of knowledge, can only be used for circular profiles with a close building tolerance, to a nominal width DNDOO, as the spacer members used, consisting of concrete and the associated mesh, result in a very high weight and thus lack of stability in respect of the air-filled tube lining, when the annular gap is increased (wall thickness of greater than 30 mm), with a lining length of about 50m. That means that it is also not possible to use that lining with larger nominal widths, without additional stabilising measures for the lining.

In the event of the duct suffering from severe corrosion, in particular in the top region thereof, when the above-mentioned concrete spacer members are used, the lining can float up, which results in disadvantageous displacement of the floor after the restoration operation.

The aim of the invention is to develop an internal lining for the restoration of sewerage systems for the range of nominal widths Due300 - 800, and all special profiles.

The problem of the invention is to provide a lining which can be used as an internal lining in the restoraton of sewerage systems in the nominal range DN 300 - 800.

The invention seeks to provide that the lining can be introduced into and fitted in position in the object to be restored, by way of a shaft installation, without any excavation. The use of the lining is to make it possible to produce any desired wall thicknesses. The lining is to have such a degree of stability that geometrical deviations are excluded, during the restoration operation.

Centering of the internal lining and easy removal of the lining must be guaranteed.

According to the invention the solid body segment internal lining comprises sheet metalsheathed hard foam segments, the sheet metal sheathing of which forms a respective groove and rabbet. Each hard foam segment has at least three pneumatic centering cylinders and at least one pneumatic lining removal cylinder for circumference reduction which is guaranteed by a lining removal gap in each segment. To prevent foreign substances from penetrating into the lining, the sheet metal sheathing is in a flush overlapping condition at the lining removal gap.

The segments are pushed non-rotatably on to a linkage arrangement provided with a linkage wedge portion. For operation of the pneumatic cylinders, each segment is provided with four air lines which are connected together by way of a push-in connection. The closure means for the lining is formed by a respective closure plate with annualr disc fitted thereon, for securing a pneumatic tube seal.

The shape and size of the sheet metalsheathed hard foam segments is determined by the nature of the profile and the dimension of the sewerage conduit to be restored. The mould which is required in any case for the production of the foam segments is formed by the sheet metal sheathing which is set in suitably milled templates. For saving on hard foam and weight, the sheet metal sheathing is used as a wear-resistant outside casing for the segments.

The templates are produced in accordance with the configuration involved and the wall thickness to be formed.

The individual segments are to be established and defined in dependence on the internal width of the entry openings of the shaft structures and installability in the shaft structure.

The invention is described in greater detail hereinafter by reference to the example of a duct with a DN 500 circular profile with an entry opening with an internal width of 600 mm, a shaft internal width of 1000 mm, and a wall thickness to be formed of 35 mm.

In the accompanying diagrammatic drawings: Figure 1 is a longitudinal section through a circular sheathing in the installed condition, and Figure 2 is a cross-section through an installed circular sheathing.

The parameters of the object to be restored give rise to the following circumstances for construction and use of the solid body segment internal lining: The sheet metal-sheathed hard foam segments 2 are to be produced in the form of a circular configuration, with a diameter of 430mm. Their length is-300 mm, on the basis of the shaft dimensions.

For the purposes of centering the lining, at least three pneumatic centering cylinders 6 are foamed in position in each segment. A lining removal gap 12 which is formed in the foaming process, in each segment, is provided with a pneumatic lining removal cylinder 7 which is also foamed in position.

For operation of the pneumatic cylinders 6 and 7, four air lines 8 with push-in connections are also foamed into each segment.

The opening for the linkage arrangement 1 and the linkage wedge portion 10 guarantees an absolutely identical fit for mounting of the individual sheet metal-sheathed hard foam segments 2 including the four connectable air lines 8. For closing off the lining, the arrangement includes a closure or terminal plate 3 which is 425 mm in diameter and an annular disc 4 which is of a diameter of 425 mm, for accommodating the pneumatic tube seal.

For receiving the individual lining segments, a screwable linkage arrangement 1 consisting of individual parts of a length of 700 mm is produced.

The length of the individual parts if determined by the shaft diameter and suitability of installation.

By means of suitable methods, for example a high pressure jet method, a pulling cable, including the air lines 8, is jetted into the sewerage conduit to be restored.

The operation of installing the lining in the shaft begins with the step of screwing together a portion of the linkage arrangement 1 and the terminal plate 3 with the annular disc 4. The cable is then connected into the receiving means 11. The first segment which is introduced by way of the shaft installation is pushed on to the linkage arrangement 1 and connected to the two air lines 8 which are required for controlling the centering and liningremoval operations. The pneumatic tube seal 5 is likewise connected to the air line 9. The operation of introducing and fitting the hard foam segments 2 is repeated alternately with the operation of installing the linkage arrangement 1 until the definitive lining length is attained. To provide the terminal closure, a closure or terminal plate 3 with annular disc 4 and a secured pneumatic tube seal 5, with receiving means for the abutment means 11, is screwed in position, and an air line 9 is connected to the pneumatic tube seal.

A second cable is fitted to the receiving means 11, for precisely varying the position of the assembly of the lining.

After setting the lining in position in the desired operating section, the centering cylinders 6 are pneumatically extended. For the purposes of sealing off the ends of the lining, the two pneumatic tube seals 5 are now pumped up by way of the air line 9. The seal is checked to ensure that it is properly operable by manometric checking outside the duct.

After the lining has been used for restoring the operating portion in question and after the time of removing the lining has been reached, the pneumatic centering cylinders 6 are retracted, the two pneumatic tube seals 5 are vented and the pneumatic lining-removal cylinders 7 are actuated for reducing the periphery of the lining. The position of the lining can now be altered by way of the cable, to move it to the following working portion.

The construction according to the invention makes it possible to produce a lining for any desired kind of configuration (circular, egg-shaped, mouthshaped) and any diametr of a sewerage system DN 300 800 to be restored.

The configuration of the arrangement in the form of a segment lining which can be installed on site provides the condition for a mode of operation which does not involve an excavation in the restoration process.

Claims

1. A solid body segment internal lining for the restoration of underground sewerage systems, which is introduced by way of the shaft structure and installed therein, characterised in that sheet metalsheathed hard foam segments in which the sheet metal sheathings respectively form a groove and rabbet and each segment has at least three pneumatic centering cylinders and at least one pneumatic lining-removal cylinder for reducing the periphery of the lining is pushed non-rotatably on to a linkage arrangement provided with a linkage wedge portion, wherein each segment is provided with four air lines for the pneumatic cylinders and a closure plate with annular disc fitted thereto securing a pneumatic tube seal is braced in position at each of the ends of the lining.

2. A solid body segment internal according to Claim 1 characterised in that the respective shape of the hard foam segments is selected in accordance with the kind of profile required from the construction point of view.

3. A solid body segment internal lining according to Claim 1 and Claim 2 characterised in that each hard foam segment has a lining-removal gap for reducing the periphery of the lining in the removal operation.

4. A solid body segment internal according to Claim 9 characterised in that the sheet metal sheathing of each hard foam segment has an overlap in the region of the linig-removal gap.

5. A solid body segment according to Claim 1 constructed , arranged and adapted to operate substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings.