GB2524484A

GB2524484A - Shoring system

Info

Publication number: GB2524484A
Application number: GB1405173.4A
Authority: GB
Inventors: Ian Lyons
Original assignee: SKINNERS DESIGN Ltd
Current assignee: SKINNERS DESIGN Ltd
Priority date: 2014-03-24
Filing date: 2014-03-24
Publication date: 2015-09-30
Anticipated expiration: 2034-03-24
Also published as: GB2534078A; GB201405173D0; GB2524484B; GB2534078B; GB201605325D0

Abstract

A system for shoring a trench wall 12 comprises a plurality of shoring members 4 and a plurality of shutters. Each shoring member is provided with means 10for fixing that shoring member to the base 3 of the trench in a substantially upright position. At least one shutter is positioned between each pair of adjacent shoring members so as to be braced against the trench wall by engagement with the shoring members. Also disclosed is a laterally extending bracket for releasably fixing the shoring member to a concrete foundation.

Description

SHORING SYSTEM

TECHNICAL FIELD

The present disclosure relates to a system for shoring a side wall of a trench, and to a method of shoring a side wall of a trench. The invention is particularly concerned with a system for, and method of, shoring a trench used in underpinning of an existing building.

BACKGROUND

In construction or renovation, underpinning is the process of strengthening the foundation of an existing building or other structure. Underpinning can be necessary for a variety of reasons: * The original foundation is simply not strong or stable enough.

* The usage of the structure has changed.

* The properties of the soil supporting the foundation can have changed (possibly through subsidence) or were mischaracterised during design.

* The construction of nearby structures necessitates the excavation of soil supporting existing foundations.

* To increase the depth or load capacity of existing foundations to support the addition of another storey to the building (above or below grade).

* It is more economical, due to land price or otherwise, to work on the present structure's foundation than to build a new one.

* Earthquake, flood, drought or other natural causes have caused the structure to move, thereby requiring stabilisation of foundation soils and/or footings.

Underpinning can be accomplished by extending the foundation in depth or in breadth so it either rests on a more supportive soil stratum or distributes its load across a greater area.

Use of micropiles and jet grouting are common methods in underpinning. An alternative to underpinning is the strengthening of the soil by the introduction of a grout, including expanding urethane-based engineered structural resins. Some of these processes are expensive and elaborate.

The aim of the invention is to provide a system for, and method of, shoring a side wall of a trench which is simpler and cheaper than known systems and methods.

SUMMARY OF THE INVENTION

Aspects of the present disclosure relate to a system for, and method of, shoring a side wall of a trench, and in particular to such a system and method for shoring the side wall of a trench prior to underpinning of an existing building wall.

A further aspect of the present invention relates to a system for shoring a trench wall, the system comprising a plurality of shoring members and a plurality of shutters, each shoring member being provided with means for fixing that shoring member to the base of the trench in a substantially upright position, wherein at least one shutter is positioned between each pair of adjacent shoring members so as to be braced against said trench wall by engagement with said shoring members.

A concrete foundation can constitute the base of the trench.

Each shoring member can be constituted by a shutter upright and a shutter channel member.

Preferably, the concrete foundation is formed with a respective hole for receiving the lower end of each of the shutter uprights.

Each shutter upright can be provided with a laterally-extending flange at its lower end portion, said flange being bolted, in use, to the concrete foundation.

The flange of each shutter upright can be fixed to that shutter upright by means of a connection portion at a predetermined distance from the lower end of that shutter upright so that, in use, the lower end of that shutter upright extends below the concrete foundation.

Each shutter upright can be provided with a plurality of apertures at its lower end portion, and the connection portion of the associated flange can be provided with apertures, the apertures of the connection portion being aligned, in use, with apertures of the lower end portion of that shutter upright, so that the connection portion is connectible to the lower end portion of the shutter upright by pins passing through said aligned apertures and by clips passing through holes provided in the ends of the pins.

Each shutter channel member can be positioned, in use, between the associated shutter upright and said trench wall.

Each shutter channel member can be provided with a respective shutter engagement portion for engaging the edge portion of a shutter positioned between the associated shutter upright and an adjacent shutter upright.

Each shutter channel member can be provided with two shutter engagement portions for engaging with shutters on either side of the associated shutter upright.

Each shutter channel member can be of 1-shaped cross-section, having a projection extending away from a base plate, those parts of the base plate on opposite sides of the projection defining two shutter engagement portions, each shutter channel member being positioned between the associated shutter upright and said trench wall with the projection in contact with said trench wall, thereby defining gaps between the shutter engagement portions and said trench wall, said gaps being sized to receive the edge portion of a shutter in sliding engagement.

The system can further comprise a respective bracing member associated with each of the shoring members, each bracing member acting between the associated shutter upright and a surface opposite to that shutter upright.

Each bracing member can have a connection portion, and a bracing plate, the connection portion being connectible to the associated shutter upright, and the bracing plate being movable relative to the connection portion to force the bracing plate against said surface.

Each bracing member can include a main arm fixed to the connection portion of that bracing member, the main arm and the bracing plate being in screw-threaded engagement whereby the bracing plate can be moved away from the connection portion to brace against said surface.

In a preferred embodiment, a building wall which requires underpinning defines said surface.

Each shutter upright can be provided with a plurality of apertures at its upper end portion, and the connection portion of the associated bracing member can be provided with apertures, the apertures of the connection portion being aligned, in use, with apertures of the upper end portion of that shutter upright, so that the connection portion is connectible to the upper end portion of the shutter upright by pins passing through said aligned apertures and by clips passing through holes provided in the ends of the pins.

The system can further comprise at least one step member, the or each step member having a platform for providing support for a workman's foot and a connection portion, the connection portion being provided with apertures, the apertures of the connection portion being aligned, in use, with apertures of the upper end portion of a shutter upright, so that the connection portion is connectible to the upper end portion of that shutter upright by pins passing through said aligned apertures and by clips passing through holes provided in the ends of the pins.

The platform of the or each step member can be pivotally attached to its connection member.

At least two of the shutter uprights can be of such a length as to extend above the top of the trench, and the system can further comprise a hoist connected to said extended shutter uprights.

A plurality of shutters can be positioned between each pair of adjacent shoring members so as to be braced against said trench wall by engagement with said shoring members.

In a still further aspect of the present invention there is provided a shoring member for mounting to a concrete foundation in a substantially upright position, the shoring member comprising a laterally-extending bracket for releasably fixing the shoring member to the concrete foundation, wherein said laterally-extending bracket is spaced apart from a lower end of the shoring member such that, in use, the lower end of the shoring member locates to a side of the concrete foundation. In use, the bracket can abut an upper surface of the concrete foundation. The shoring member can extend downwardly alongside the concrete foundation. In use, the shoring member can engage the side of the concrete foundation.

The bracket can be configured to receive one or more mechanical fasteners, such as a bolt, to mount the shoring member to the concrete foundation. The position of the laterally-extending bracket along said shoring member can be adjustable. The shoring member can comprise means for mounting a shutter on one or both sides thereof. The shoring member can extend below the depth of the concrete foundation. The concrete foundation can be provided in a trench.

In a further aspect of the present invention there is provided a method of shoring a wall of a trench, the method comprising fixing a plurality of shutter uprights into the base of the trench, and positioning shutters between each pair of shutter uprights with the shutters braced against said trench wall.

The method can further comprise the step of forming a concrete foundation as the base of the trench prior to the fixing of the shutter uprights.

The method can also further comprise the step of forming holes in the concrete foundation for receiving the shutter uprights.

Preferably, the method further comprises the step of bolting each shutter upright to the concrete foundation.

The method can further comprise positioning a respective bracing member between each shutter upright and an upright surface opposite to said trench wall.

In yet a further aspect of the present invention there is provided a method of underpinning an existing wall of a building, the method comprising the steps of:- (a) digging a trench on the inside of said building wall; (b) laying a concrete foundation at the base of the trench; (c) mounting shutter uprights in holes formed in the concrete foundation; (d) fixing the shutter uprights to the concrete foundation; (e) positioning shutters between each pair of adjacent shutter uprights so as to be braced against that wall of the trench opposite the building wall; and (f) carrying out underpinning work on the building wall.

This underpinning method can further comprise the step of positioning a respective shutter channel member between each shutter upright and said trench wall, the shutters being held against said trench wall by engagement with the shutter channel members.

Preferably, the underpinning method can further comprise the step of bracing each shutter upright towards said trench wall to hold the shutters firmly in place against said trench wall by bracing devices acting between that shutter upright and the inside of the building wall.

Within the scope of this application it is expressly envisaged that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and/or in the following description and drawings, and in particular the individual features thereof, can be taken independently or in any combination. Features described in connection with one embodiment are applicable to all embodiments, unless such features are incompatible.

BRIEF DESCRIPTION OF THE DRAWINGS

S

An embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a trench dug prior to underpinning work to be carried out on an existing building wall, and shows a shoring system constructed in accordance with the invention; Figure 2 is a schematic end elevation of the trench and shoring system of Figure 1; Figure 3 is a perspective view of a shutter upright forming part of the system of Figure 1; Figure 4 is a perspective view of a shutter channel member forming part of the system of Figure 1; Figure 5 is a perspective of a shutter forming part of the system of Figure 1; and Figure 6 is a perspective view of a support arm assembly forming part of the system of Figure 1.

DETAILED DESCRIPTION OF AN EMBODIMENT

Referring to the drawings, Figures 1 and 2 show a building wall 1 which requires underpinning. The first step in providing underpinning is to dig a trench 2 on the inside of the wall 1. This trench 2 must be deep enough to extend below the original foundation (not shown) of the wall 1, and will be several feet deep (typically about 6 feet). A new concrete foundation 3 (see Figure 2) is laid at the base of the trench 2 to provide support for the underpinning. A plurality of shoring members 4 are then fixed to the concrete foundation 3.

Each shoring member 4 is constituted by a shutter upright 5 and a shutter channel member 6.

As shown in Figure 3, each shutter upright 5 has a pair of laterally-spaced vertical walls 7 and 8 which extend away from a base 9. Each wall 7, 8 is formed with a plurality of equispaced apertures 7a and 8a towards its lower end, and with a plurality of equispaced apertures 7b and Sb towards its upper end. Each shutter upright 5 is provided with a laterally-extending flange 10 positioned a short distance from its lower end portion. That lower end portion of each shutter upright 5 is located in a respective hole 11 formed adjacent to the inner edge of the concrete foundation 3, that hole extending below the concrete foundation to ensure that that shutter upright S is held firmly against the adjacent trench wall 12 when that shutter upright is fixed to the concrete foundation 3 by a respective bolt 13 passing through the flange 10.

As shown in Figure 3, the flange 10 of each shutter upright 5 is fixed to the lower end of that shutter upright by means of pins 14 and clips 15, the pins passing through apertures ba formed in the flange 10 and through aligned apertures 7a and Sa. Each pin 14 has a through hole (not shown) adjacent each end thereof, a respective clip 15 passing through each through hole to fix the associated flange 10 to its shutter upright 5.

Figure 4 shows a shutter channel member 6 constituted by a T-shaped member having a base plate 16 and a longitudinally-extending projection 17, those portions of the base plate on either side of the projection constituting shutter engagement portions as described below.

Figure 5 shows a shutter 18. Each shutter channel support member 6 is positioned, in use, between the associated shutter upright 5 and the adjacent trench wall 12, with the projection 17 in engagement with the trench wall, and with the shutter engagement portions spaced from that trench wall by a distance substantially the same as the thickness of the shutter.

Figure 6 shows a support arm assembly 19 which has a main arm 20, a flange 21 for connection to the associated shutter upright 5, and a bracing plate 22 mounted on a screw-threaded member 23 which engages with a corresponding screw-threaded member 24 provided in the main arm 20. The flange 21 is formed with pairs of aligned apertures 21a. In use, each support arm assembly 19 is fixed to the associated shutter upright 5 by means of pins 14 and clips 15 (see Figure 3), the pins passing through aligned apertures 21a, 7b and Sb. The bracing plate 22 of each support arm assembly 19 can then be forced against the inside face of the wall 1 by manipulation of the screw-threaded members 23 and 24.

In order to install the shoring system, holes 11 are drilled in the concrete foundation 3 after the trench 2 has been dug and the concrete foundation has been laid and allowed to set. A respective shutter upright 5 is then positioned in each of the holes 11. The shutter uprights 5 are then fixed to the concrete foundation 3 by fixing their flanges 10 to the shutter uprights using the pins 14 and the clips 15, and by bolting the flanges to the concrete foundation using the bolts 13. A respective shutter channel member 6 is then positioned between each shutter upright 5 and the adjacent trench wall 12 with the projection 17 lying against the trench wall. Each shutter upright 5 is then braced into position by fixing the associated support arm assemblyl9 to that shutter upright by fixing its flange 21 to that shutter upright using the respective pins and clips, and then by forcing the bracing plate 22 of that support arm assembly against the wall 1 by manipulation of the screw-threaded members 23 and 24.

A plurality of shutters 18 can then be slid into position between each pair of adjacent shoring members 4, with each shutter being positioned against the trench wall 12 owing to its engagement with the shutter engagement portions of the two shutter channel members 6 of those shoring members. The support arm assemblies 19 can then be tightened to force the shutters firmly against the trench wall 12.

Once the shoring system has been installed, workmen can access the trench 2 to provide underpinning for the wall 1, the underpinning being shown schematically by the reference numeral 25.

Figure 1 also shows an alternative form of shutter channel member 6' for use with the last of a series of shutter uprights 5. This shutter channel member 6' is of L-shaped cross-section, having a projection 17' extending from one end of a base plate 16' which thus defines a single shutter engagement portion for forcing the adjacent shutters 18 against the trench wall 12.

It will be apparent that modifications could be made to the shoring system described above.

For example, brackets similar to the flange 10 could be attached to one or more of the shutter uprights 5 to constitute steps to facilitate access by workmen to the floor of the trench 2. Such a step could have a step portion pivotally mounted to a connection portion fixed to a shutter upright 5 by means of pins and clips. This enables a step to be pivoted upwardly or downwardly to provide improved access within the trench 2. The shutter uprights 5 could also be extended upwards within the building of which the wall 1 is part to support a hoist arrangement to assist with raising and lowering construction equipment and materials.

Preferably, at least two of the shutter uprights 5 would be extended in this manner. The shutter uprights 5 could also be used to support internal scaffolding within the trench 2.

The shoring system described above could be modified to support the walls of trenches dug for other purposes. For example, where a pipeline is to be laid, both side walls of a trench could be provided with shoring systems to support those walls against collapse. In this case, each support arm assembly would be modified to have flanges at each end for connection to respective shutter uprights 5, and the main arm 20 the assembly would be of telescopic construction so that the length of each assembly could be extended to press outwardly against the shutter uprights.

In some cases, where the floor of a dug trench is sufficiently firm, it may be possible to dispense with the concrete foundation 3, and fix the flanges 10 of the shutter uprights 5 to the trench floor using spikes.

Additional structural features can be used to augment the shoring system and thereby provide added functionality to the shoring system. For example, in environments where water ingress into the trench is possible such as in heavy rainfall, it would be desirable to keep the trench from flooding. In this regard, the shoring system can be provided with one or more flood gates (not shown) to substantially inhibit water ingress into the trench. The flood gate comprises a first gate portion and a second gate portion, each of which provide a blocking surface. The first gate portion and the second gate portion are pivotably connected to the shoring system at opposing sides across the width of the trench. In this manner, the gate portions can be placed in an open configuration so that access can be provided to the trench, or a closed configuration in which side of the gate portions abut against one another to form a seal to inhibit water ingress into the trench. A blocking panel can also be provided beneath the gate portions, which blocking panel can extend across the width of the trench and along the bottom of the trench. The blocking panel further acts to inhibit water ingress into the trench even when the flood gates are in an open configuration. The blocking panel can be pivotably connected to the shoring system, such that it can be placed in an upright position for inhibiting water ingress into the trench, and a rested position, whereby a surface of the blocking panel can rest on the base of the trench.

Claims

CLAIMS: 1. A system for shoring a trench wall, the system comprising a plurality of shoring members and a plurality of shufters, each shoring member being provided with means for fixing that shoring member to a base of a trench in a substantially upright position, wherein at least one shutter is positioned between each pair of adjacent shoring members so as to be braced against said trench wall by engagement with said shoring members.
2. A shoring system as claimed in claim 1, wherein a concrete foundation constitutes the base of the trench.
3. A shoring system as claimed in claim 2, wherein each shoring member is constituted by a shutter upright and a shutter channel member.
4. A shoring system as claimed in claim 3, wherein the concrete foundation is formed with a respective hole for receiving a lower end portion of each of the shutter uprights.
5. A shoring system as claimed in claim 4, wherein each shutter upright is provided with a laterally-extending flange at its lower end portion, said flange being bolted, in use, to the concrete foundation.
6. A shoring system as claimed in claim 5, wherein the flange of each shutter upright is fixed to that shutter upright by means of a connection portion at a predetermined distance from the lower end portion of that shutter upright so that, in use, the lower end portion of that shutter upright extends below the concrete foundation.
7. A shoring system as claimed in claim 6, wherein each shutter upright is provided with a plurality of apertures at its lower end portion, and the connection portion of the associated flange is provided with apertures, the apertures of the connection portion being aligned, in use, with apertures of the lower end portion of that shutter upright, so that the connection portion is connectible to the lower end portion of the shutter upright by pins passing through said aligned apertures and by clips passing through holes provided in the ends of the pins.
8. A shoring system as claimed in any one of claims 3 to 7, wherein each shutter channel member is positioned, in use, between the associated shufter upright and said trench wall.
9. A shoring system as claimed in claim 8, wherein each shutter channel member is provided with a respective shutter engagement portion for engaging an edge portion of a shutter positioned between the associated shutter upright and an adjacent shutter upright.
10. A shoring system as claimed in claim 9, wherein each shutter channel member is provided with two shutter engagement portions for engaging with shutters on either side of the associated shutter upright.
11. A shoring system as claimed in claim 10, wherein each shutter channel member has a T-shaped cross-section with a projection extending away from a base plate, those parts of the base plate on opposite sides of the projection defining two shutter engagement portions, each shutter channel member being positioned between the associated shutter upright and said trench wall with the projection in contact with said trench wall, thereby defining gaps between the shutter engagement portions and said trench wall, said gaps being sized to receive the edge portion of a shutter in sliding engagement.
12. A shoring system as claimed in any one of claims 3 to 11, wherein a respective bracing member is associated with each of the shoring members, each bracing member acting between the associated shutter upright and a surface opposite to that shutter upright.
13. A shoring system as claimed in claim 12, wherein each bracing member has a connection portion, and a bracing plate, the connection portion being connectible to the associated shutter upright, and the bracing plate being movable relative to the connection portion to force the bracing plate against said surface.
14. A shoring system as claimed in claim 13, wherein each bracing member includes a main arm fixed to the connection portion of that bracing member, the main arm and the bracing plate being in screw-threaded engagement whereby the bracing plate can be moved away from the connection portion to brace against said surface.
15. A shoring system as claimed in any one of claims 12 to 14, wherein a building wall which requires underpinning defines said surface.
16. A shoring system as claimed in any one of claims 13 to 15, each shutter upright is provided with a plurality of apertures at its upper end portion, and the connection portion of the associated bracing member is provided with apertures, the apertures of the connection portion being aligned, in use, with apertures of the upper end portion of that shutter upright, so that the connection portion is connectible to the upper end portion of the shutter upright by pins passing through said aligned apertures and by clips passing through holes provided in the ends of the pins.
17. A shoring system as claimed in claim 16, further comprising at least one step member, the or each step member having a platform for providing support for a workman's foot and a connection portion, the connection portion being provided with apertures, the apertures of the connection portion being aligned, in use, with apertures of the upper end portion of a shutter upright, so that the connection portion is connectible to the upper end portion of that shutter upright by pins passing through said aligned apertures and by clips passing through holes provided in the ends of the pins.
18. A shoring system as claimed in claim 17, wherein the platform of the or each step member is pivotally attached to its connection member.
19. A shoring system as claimed in any one of claims 3 to 18, wherein at least two of the shutter uprights is of such a length as to extend above the top of the trench, and the system further comprises a hoist connected to said extended shutter uprights.
20. A shoring system as claimed in any one of claims 1 to 19, wherein a plurality of shutters are positioned between each pair of adjacent shoring members so as to be braced against said trench wall by engagement with said shoring members.
21 A shoring member for mounting to a concrete foundation in a substantially upright position, the shoring member comprising a laterally-extending bracket for releasably fixing the shoring member to the concrete foundation, wherein said laterally-extending bracket is spaced apart from a lower end of the shoring member such that, in use, the lower end of the shoring member locates to a side of the concrete foundation.
22. A method of shoring a wall of a trench, the method comprising fixing a plurality of shutter uprights into the base of the trench, and positioning shutters between each pair of shutter uprights with the shutters braced against said trench wall.
23. A shoring method as claimed in claim 22, further comprising the step of forming a concrete foundation as the base of the trench prior to the fixing of the shutter uprights.
24. A shoring method as claimed in claim 23, further comprising the step of forming holes in the concrete foundation for receiving the shutter uprights.
25. A shoring method as claimed in claim 24, further comprising the step of bolting each shutter upright to the concrete foundation.
26. A shoring method as claimed in any one of claims 22 to 25, further comprising positioning a respective bracing member between each shutter upright and an upright surface opposite to said trench wall.
27. A method of underpinning an existing wall of a building, the method comprising the steps of:- (a) digging a trench on the inside of said building wall; (b) laying a concrete foundation at the base of the trench; (c) mounting shutter uprights in holes formed in the concrete foundation; (d) fixing the shutter uprights to the concrete foundation; (e) positioning shutters between each pair of adjacent shutter uprights so as to be braced against that wall of the trench opposite the building wall; and (f) carrying out underpinning work on the building wall.
28. An underpinning method as claimed in claim 27, further comprising the step of positioning a respective shutter channel member between each shutter upright and said trench wall, the shutters being held against said trench wall by engagement with the shutter channel members.
29. An underpinning method as claimed in claim 27 or claim 28, further comprising the step of bracing each shutter upright towards said trench wall to hold the shutters firmly in place against said trench wall by bracing devices acting between that shutter upright and the inside of the building wall.
30. A shoring system substantially as hereinbefore described with reference to, and as illustrated by, the accompanying drawings.
31. A method of shoring a wall of a trench, the method being substantially as hereinbefore described.
32. A method of underpinning an existing wall of a building, the method being substantially as hereinbefore described.