GB2483863A

GB2483863A - Interlocking modular manhole system

Info

Publication number: GB2483863A
Application number: GB1015839.2A
Authority: GB
Inventors: Tom Body
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-09-21
Filing date: 2010-09-21
Publication date: 2012-03-28
Also published as: GB201015839D0

Abstract

A plastic or composite modular Manhole System includes plastic or composite units which interlock together to form a water tight manhole or gully chamber. The chamber may be used to form the top section of a manhole and support the manhole cover and frame of a typical foul or surface water manhole. The plastic modular system could also be used for surface water gullies to support a cover and grate. The system is intended to replace the conventional brickwork element of a standard manhole of gully and each unit may be dimensioned to match the thickness of a standard brick. The units may also be available in split and angled courses, so 37.5mm thick and 1 in 40 cross fall or gradient respectively.

Description

Plastic Modular Manhole System This invention relates to a system for forming a conventional brick manhole or gully chamber, but using a plastic modular system.

The existing system of building a manhole or gully requires the use of several operations and materials to achieve the desired chamber, which is located on top of pre-cast concrete manhole rings or gully pots. However the conventional construction can and does lead to a number of difficulties and failures. For example; the specified brickwork mortar strength is not achieved due to incorrect mix or due to outside temperature whilst mixing and curing.

There are many other contributing factors that lead to the failure of conventional manhole and gully chambers. These include; use of saturated bricks during construction, the road being trafficked prior to the brickwork mortar reaching the correct strength, use of unskilled labour resulting in poor workmanship and incorrect bond in the brickwork.

To overcome the problems that have been reoccurring for decades, the Plastic Modular Manhole System will be manufactured to replace the conventional brickwork system along with the standard metallic cover and frame. The system will be designed to meet the standard highway requirements, but at the same time it will be very fast and simple to install thus minimising the risk of future failure of the manhole cover and frame.

The design will be developed to produce a system that massively reduces construction time of manholes and gullies. It will also remove the requirement for skilled labour and minimise the failure of manhole covers and frames and the associated resulting effects on the road surface.

The Plastic Modular Manhole System will consist of a number of manufactured plastic or composite units, which interlock when stacked one on top of the other.

The units will sit directly onto the pre-cast concrete manhole cover slab or gully pot and the first unit (base unit) will be bonded to the concrete using a proprietary fast acting bonding agent. The following units will then be simply stacked on top and interlocked to form a plastic chamber.

The units will be dimensioned to be a direct replacement for standard brickwork and will therefore be designed to be in multiples of the normal metric brickwork dimensions. For example the standard unit depth would be 75mm (one brick deep plus the standard 10mm mortar bed).

To facilitate the variation in levels and cross falls that will be encountered on each installation due to the variations in road surface levels and designs, a separate split course unit will be manufactured which effectively forms a half depth unit (37.5mm). In addition a tapered unit will be designed with a 1 in 40 cross fall to match the standard highway carriageway cross fall. The tapered unit could be developed to incorporate a range of cross falls for varying carriageway and footway designs.

In addition to the split course unit and endless possibilities of tapered units already outlined, the standard metallic cover and frame could be made redundant by a new plastic or composite material system. The top interlocking section of the system would effectively form the normal manhole frame and seating thus doing away with the conventional ductile iron frame. The manhole cover itself could then be manufactured from a similar plastic or composite man-made material and designed to fit directly into the Plastic Modular Manhole System.

The key intention of this system is to eliminate failure in poorly constructed and maintained manholes, which in turn would lead to a decrease in road surface repairs and the associated effects of road works on the highway network.

The secondary intention for the system is to eliminate theft of metallic manhole covers and frames, which is an increasing problem for highway authorities and has many associated problems, costs and health and safety implications.

The system is primarily aimed at use in conventional manhole construction, but can easily be adapted to include conventional highway gully installations.

Claims

Claims Plastic Modular Manhole System 1. The plastic modular system comprises of plastic or composite units which interlock to form a water tight manhole or gully chamber.
2. The system would be manufactured in plastic or a similar composite material that is man made.
3. The individual units will be dimensioned to be the equivalent to 9" brickwork and each module would be the equivalent to a course of brickwork thick.
4. The units will also be available in split courses in keeping with the brickwork dimension theme.
5. To accomplish a cross fall at the top to facilitate the standard highway levels, a unit will be designed with a 1 in 40 fall and there may be further tapered units developed with alternative cross falls.
6. To aid identification of the different drainage systems, the units will be colour coded in line with national standards. Surface water systems to be coloured blue and foul sewers to be coloured brown.
7. Each unit would be clearly marked for identification of the drainage system, for example Foul or Surface water.
8. The individual units would be light weight to avoid manual handling issues.
9. The plastic modular system would be a direct replacement for the existing brickwork system.
1O.The system would be developed to incorporate a plastic or composite manhole cover and frame.