GB2293189A - Trench sheet - Google Patents

Abstract

A trench sheet has connecting means, typically in the form of a part-spiral 28, 30 for the connection of other trench sheets. These connecting means allows the trench sheets to be connected to other trench sheets such that connected trench sheets can be placed in and around corners in a ground work application. The connecting means may, in the event of damage, be removed to convert the trench sheet into a standard lap trench sheet. <IMAGE>

Description

"Trench Sheet" This invention relates especially but not exclusively to a trench sheet.

Trench sheets and trench sheet piles are used predominantly in the construction industry for a variety of ground work applications which include providing a means of support to the sides of excavations in varying types of soil conditions. There are generally two distinctive types of trench sheets, namely a lap trench sheet and an interlock trench sheet.

Lap trench sheets have little effective means of lateral restraint since interlocking of adjacent lap trench sheets usually involves overlapping a web end portion of a lap trench sheet with a web end portion of an adjacent lap trench sheet.

Interlock trench sheets have what is known in the industry as "clutches". These are curled formations at the sides of the trench sheet which provide mechanical means of restraint laterally and longitudinally.

However, these clutches are easily damaged and the vast majority of interlock trench sheets that have damaged clutches are written of since they are expensive to repair. Additionally, a special interlock trench sheet is needed when corners are encountered in the ground work application.

According to the present invention there is provided a trench sheet having connecting means for the connection of other trench sheets, wherein the connecting means allows the trench sheet to be connected to other trench sheets in the same plane or at an angle to said plane such that connected trench sheets can be placed in corners in a ground work application.

Preferably, the connecting means is removable to convert the trench sheet into a standard lap trench sheet.

Preferably, the connecting means is a part-spiral formation at the sides of the trench sheet which allows adjacent trench sheets to be connected by the interfitting of respective part-sr l formations.

Preferably, the part-spiral formation at the side of the trench sheet is adapted to interlock with the partspiral formation of the adjacent trench sheet when the adjacent trench sheet is substantially at an angle from O9Oo.

Preferably, the part-spiral formation is located on a web portion of the trench sheet.

Preferably, the part-spiral formation is displaced out of alignment with the web portion such that when adjacent part-spiral formations interlock with one another the interlocking action is facilitated by an outer surface of the respective part-spiral formations abutting an end section of the web before said partspiral formations are made to disengage with one another.

Preferably, the part-spiral formation turns through an angle of at least 1800 such that the end of the partspiral formation at one side of the trench sheet is disposed in a different direction to the end of the part-spiral formation at the other side of the trench sheet. This arrangement provides a locking action of the connecting means between adjacent trench sheets.

Preferably, when adjacent trench sheets are connected with each other by their respective connecting means there is a surface contact between the connecting means of one of said trench sheets and the adjacent trench sheet.

Preferably, the trench sheet is made from a light weight steel with high strength. The yield strength of the steel may be from 200 to 740 N/mm2.

Preferably, the trench sheets can be arranged behind other connected trench sheets to form a box pile.

An embodiment of the invention will now be described by way of example with reference to the accompanying drawings in which: Fig. 1 is a side view of various lap trench sheets in accordance with the invention; Fig. 2 is a side view of connected interlock trench sheets in accordance with the invention; Fig. 3 is a side view of the connecting means of the interlock trench sheets of Fig. 2; Fia. 4 is a close-up side view of the connected interlock trench sheets of Fig. 2; Fig. 5 is a side view of connected interlock trench sheets rotated through 45 relative to one another; Fig. 6 is a side view of connected interlock trench sheets rotated through an angle of 900 relative to one another.

Referring to the drawings a variety of lap trench sheets generally referenced as reference numeral 10 are shown in Fig. 1 having raised portions 12 and channel portions 14. The channel portions 14 are joined to the raised portions 12 by web portions 16. At one end of the lap trench sheets 10 there is a trough formation 18. The lap trench sheets 10 are connected with each other by interfitting the trough formations 18 of adjacent lap trench sheets. When lateral force is applied, the lap trench sheets 10 connected in this way resist lateral movement by the engagement of the sides of the interfitted trough formations 18 with each other.

Interlock trench sheets 20 are shown in Figs. 2 - 6 and have raised portions 22 and channel portions 24 connected to the raised portions 22 by web portions 26.

At either side of each interlock trench sheet 20 in slight disalignment with respective web portions 26 there are part-spiral formations 28 and 30.

As shown in Fig. 3 the end 28a of the part-spiral formation 28 is disposed substantially in a horizontal position and the end 30a of the part-spiral formation 30 is disposed in substantially a vertical position.

To connect interlock trench sheets 20 together the part-spiral formation 30 of one interlock trench sheet 20 interfits with the part-spiral formation 28 of an adjacent interlock trench sheet as shown in Fig. 4. In this way the respective position of the ends 28a and 30a relative to one another provide a locking action at the formed interlock junction.

The part-spiral formations 28 and 30 allow rotation of the interlock trench sheets 20 relative to one another through an angle of 0 to 900 as shown in Fig. 5 and Fig. 6. This allows the interlock trench sheets 20 to be connected in the same plane or at angles to said plane such that connected trench sheets can be placed in corners when needed in the ground work application.

The part-spiral formations 28 and 30 inevitably encounter damage through use. However, as the partspiral formations 28 and 30 are positioned on web portions 26 they may be removed to convert the interlock trench sheet to a standard lap trench sheet for further use.

Advantages of trench sheets 10 and 20 are that the connecting mechanisms allow the trench sheets to be used in a ground work construction application with increased safety since forces applied to a single trench sheet in the construction are resisted at the connecting junction so that the integrity of the trench sheet construction is maintained. The trench sheets 10 and 20 are made from a light weight and high strength steel such as DOMES which has yield strengths from 200 - 740 N/mm2 and provides a high strength steel with excellent forming properties combined with good weldability and impact strength. This combination of properties offers the potential to either save weight or to increase strength with no weight penalty, making these trench sheets suitable for many ground work applications.

Improvements and modifications may be incorporated without departing from the scope of the invention.

Claims (11)

1. A trench sheet having connecting means for the connection of other trench sheets, wherein the connecting means allows the trench sheet to be connected to other trench sheets in the same plane or at an angle to said plane such that connected trench sheets can be placed in corners in a ground work application.

2. A trench sheet as claimed in Claim 1, wherein the connecting means is removable to convert the trench sheet into a standard lap trench sheet.

3. A trench sheet as claimed in Claim 1 or Claim 2, wherein the connecting means is a part-spiral formation at the sides of the trench sheet which allows adjacent trench sheets to be connected by the interfitting of respective part-spiral formations.

4. A trench sheet as claimed in Claim 3, wherein the part-spiral formation at the side of the trench sheet is adapted to interlock with tlie part-spiral formation of the adjacent trench sheet when the adjacent trench sheet is substantially at an angle from 0-900.

5. A trench sheet as claimed in Claim 3 or Claim 4, wherein the part-spiral formation is located on a web portion of the trench sheet.

6. A trench sheet as claimed in any one of the Claims 3 to 5, wherein the part-spiral formation is displaced out of alignment with the web portion such that when adjacent part-spiral formations interlock with one another the interlocking action is facilitated by an outer surface of the respective part-spiral formations abutting an end section of the web before said part-spiral formations are made to disengage with one another.

7. A trench sheet as claimed in any one of the Claims 3 to 6, wherein the part-spiral formation turns through an angle of at least 1800 such that the end of the part-spiral formation at one side of the trench sheet is disposed in a different direction to the end of the part-spiral formation at the other side of the trench sheet.

8. A trench sheet as claimed in any one of the preceding Claims adapted to connect to adjacent trench sheets respective connecting means, wherein there is a surface contact between the connecting means of one of said trench sheets and its said adjacent trench sheet.

9. A trench sheet as claimed in any one of the preceding Claims made from a light weight steel with high strength.

10. A trench sheet as claimed in any one of the preceding Claims can be arranged behind other connected trench sheets to form a box pile.

11. A trench sheet substantially as described or illustrated in the accompanying Description and Drawings.