GB2411409A

GB2411409A - Modular inspection chamber

Info

Publication number: GB2411409A
Application number: GB0404056A
Authority: GB
Inventors: Quintin Anthony Murfin
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-02-24
Filing date: 2004-02-24
Publication date: 2005-08-31
Also published as: GB0503577D0; GB0404056D0

Abstract

A modular inspection chamber comprises a plurality of lightweight plastics sections (3) which form an internal lining to the chamber. To each section is attached a geogrid ground reinforcement strip (4). Infilling the space around the chamber with a granular particulate material supports the surrounding ground as well as the chamber cover (1) and any in-service loads imposed on the uppermost surface of the cover.

Description

241 1 409

INSPECTION CHAMBER SYSTEM

Background

Large inspection chambers for in ground services are generally constructed of precast concrete with an in-situ surround, or in-situ concrete, because of their structural ability to resist soil load forces. Shallow light vehicular duty plastic inspection chambers are economical.

The Problem The construction time, materials and labour requirement are high for large inspection chambers for in ground services constructed of precast concrete with an in-situ surround or in-situ concrete. Plastic inspection chambers are common for shallow construction and light vehicular duty areas, however the material is not efficient structurally for deep chambers. Most inspection chambers shafts are also required to support the loads imposed by the Inspection Chamber access cover frame.

The Invention An object of this invention is to utilise the ability of reinforced soil construction to reduce retained earth pressures on soil containing facings thus allowing shafts liners of large inspection chambers for in ground services to have a lower earth retaining strength requirement. To avoid the inspection chambers shafts having to support the loads imposed by the Inspection Chamber access cover frame, the frame is supported by a foundation bed supported on the surrounding reinforced soil.

Invention Detail A preferred embodiment of the invention will now be described, by way of example, with reference to the accompanying drawing in which Figure I shows a diagrammatic vertical section through the system.

An Inspection Chamber Cover 1 has a Concrete Bed and Surround 2 that is supported by the reinforced soil on which it is founded. Synthetic Shaft Units 3 that have Geogrid Reinforcement 4 connected to them around their periphery. The Synthetic Shaft Units 3 may be circular or square in plan. The Geogrid Reinforcement 4 is designed in width and spacing to be earth retaining under the surface load and soil conditions prevailing. The soil utilised in between the Geogrid Reinforcement 4 may need to be granular graded stone aggregate. The lowest chamber unit has Connections for Service Pipes 5 and a Base Plate 6. If required Synthetic Shaft Units 3 may be sealed at their junctions to prevent ingress of ground water; in which case the Geogrid Reinforcement 4 must be designed to provide sufficient resistance to floatation taking into account the weight of the structure.

Claims

1. A reinforced soil inspection chamber system consisting of a synthetic in ground shaft inspection chamber with reinforced soil retaining walls.

2. A reinforced soil inspection chamber system as claimed in claim I that has an inspection chamber cover frame bedded on a foundation supported by reinforced soil.

3. A reinforced soil inspection chamber system as claimed in claim 1 with a chamber base plate.

4. A reinforced soil inspection chamber system as claimed in claim I with shaft units sealed against the ingress of ground water at their junctions.

5. A reinforced soil inspection chamber system as claimed in claim 1,3 sealed against the ingress of ground water at the junction with a chamber base plate.

6. A reinforced soil inspection chamber system as substantially described herein and in Figure 1.

Amendments to the claims have been filed as follows

1. A modular inspection chamber to be buried in the ground comprising modular lightweight plastics sections forming the internal lining to the chamber, to which are attached horizontal geogrid strips which in conjunction with predominantly granular particulate material f fling forms a reinforced soil block surround to the chamber lining which supports the surrounding ground, the weight of any inspection chamber cover, and any in service loads imposed on the surface of the inspection chamber cover.

2. A modular inspection chamber as claimed in claim I where the bottom section forms a pan 3. A modular inspection chamber as claimed in claims 1,2 where the joints between the sections are sealed against the ingress of ground water.

4. A modular inspection chamber according to any of the preceding claims wherein at least some of the modular sections have a circular crosssection.

5. A modular inspection chamber according to any one of claims I to 3 wherein at least some of the modular sections have a rectangular crosssection.