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(11) | EP 0 396 421 A2 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Connection between panels in a trench-box |
| (57) A clip (364) engages flat members (224, 226) which are respectively welded to the
top of a base panel (200) and to the bottom of a top panel (202) on the outside faces
(200A, 202A) of the panels (200, 202) to prevent the base panel (200) from folding
inwardly, even though the base panels (200) of a trench-box (SB) are only interconnected
with each other by a single pair of struts (400) near the tops thereof. |
[0002] This invention is one of two inventions which are the subject of two co-pending patent applications both filed on the same day by the present applicant. The other patent application is as follows:-
patent application Serial No. 90 entitled "TRENCH-BOX PANEL" - reference 799P57729.
[0003] A trench-box is used to shore up the walls of an excavation and comprises panels which are spaced-apart from each other and are inter-connected by extendible and retractable struts. A deep excavation may require a pair of spaced-apart lower, or base, panels to be connected respectively to a pair of upper extension, or top, panels in order for the panels to extend the full depth of the excavation. It is usual for the base panels to be inter-connected with each other by one or two pairs of base-panel-struts and for the top panels to be inter-connected with each other by a further pair of top-panel-struts. Each base panel is required to be rigidly connected to its respective top panel in order for the two panels in combination to withstand the very great pressures of the earth walls of the excavation upon the panels.
[0004] It is an object of this invention to provide a means of inter-connecting a lower panel to an upper panel very rigidly indeed.
[0005] This invention provides a trench-box panel assembly as claimed in each of claims 1 to 4, to which reference is directed.
[0006] The invention will be described by way of example with reference to the drawings, wherein:-
FIG. 1 is an elevational view of the rear face (inner face) of a top panel (upper extension panel);
FIG. 2 is a plan view corresponding to Fig. 1;
FIG. 3 is an end view corresponding to Figs. 1 and 2;
FIG. 4 is an enlarged view of an end-post as seen in Fig. 3;
FIG. 5 is an elevational view of the end-post of Fig. 4;
FIG. 6 is an elevational view of the rear face (inner face) of a base panel;
FIG. 7 is an end view corresponding to Fig. 6;
FIG. 8 is a plan view corresponding to Figs. 6 and 7;
FIG. 9 is an enlarged view as seen in Fig. 7 of an end-post;
FIG. 10 is an elevational view of the end-post of Fig. 9;
FIG. 11 is an enlarged view as seen in Fig. 7 of a nose sub-assembly;
FIG. 12 is an elevational view of the nose sub-assembly alone of Fig. 7;
FIG. 13 is a section on 13-13 of Fig. 12;
FIG. 14 is an enlarged fragmentary view in side elevation of the top of the base panel and the bottom of the top panel, seen from the same directions as in Figs. 3 and 7, showing the two panels connected together;
FIG. 15 is a view on arrow 15 in Fig. 14;
FIG. 16 illustrates part of a spacer member in Figs. 14 and 15;
FIGS. 17, 18 and 19 are an elevational view, a side view and a plan view respectively of a peg member shown in Figs. 14 and 15;
FIG. 20 is a fragmentary perspective view of one side edge of one of the panels before attachment of the vertical angle member and vertical flat member to seal the horizontal cavities formed by the C-section members;
Fig. 21 is a fragmentary plan view of a side edge of a modified panel; and
FIG. 22 shows a trench-box embodying the invention, in use in an excavation in which a pipe is laid.
[0007] A trench-box SB (Fig. 22) embodying the invention comprises a pair of mutually spaced-apart base panels 200 interconnected by extendible and retractable struts 400 and a pair of mutually spaced-apart top panels 202 also interconnected by similar struts 400. Each top panel 202 is an upper extension of a respective one of the base panels 200, to which it is firmly and rigidly connected by panel-connecting means 308 (Figs. 14, 15 and 16) comprising panel-securing means 316 and panel-positioning means 318.
[0008] Each base panel 200 (Figs. 6 to 13) and each top panel 202 (Figs. 1 to 5) comprises an array of respective horizontal elongate "C-section" members 210, one on top of another and welded together. Each such horizontal C-section member 210 (see Figs. 11 and 20) comprises a horizontal base element 210a, a pair of mutually-facing vertical elements 210b, which respectively extend upwardly from inside and outside edges of the horizontal base element 210a, and a pair of flange elements 210c which extend inwardly towards each other from respective upper edges of the vertical elements 210b. Each horizontal C-section member 210 is arranged with its horizontal base element 210a lowermost and its flange elements 210c uppermost, so that adjacent horizontal C-section members 210 have the horizontal base element 210a of the upper C-section member 210 resting on, and welded at w to, the flange elements 210C of the lower C-section member 210, the welding w being continuous along their lengths, to define a horizontally-extending cavity 220. The cavity 220 is closed by the elements 210a, 210b and 210c except at the ends of the cavity 220.
[0009] Each base panel 200 and each top panel 202 also comprises a respective horizontal box-section member 222 resting upon, and welded at w continuously along its length to the flange elements 210c of the uppermost horizontal C-section member 210. A robust flat member 224 is welded at w continuously along its length to the top element 222a of the box-section member 222 of panel 202 A slightly wider robust flat member 226 (Fig. 17) is similarly welded to the top element 222a of member 222 of panel 200.
[0010] Each base panel 200 and each top panel 202 has a front face 200A, 202A and a rear face 200B, 202B formed by the vertical elements 210b of the C-section members 210 and corresponding vertical elements 222b of box-section members 222. Each panel 200, 202 also has side edges 200C, 202C formed by the ends of the members 210, 222.
[0011] A portion 226a of flat member 226 of base panel 200 projects forwardly of the front face 200A of base panel 200, that is, forwardly of the forward vertical elements 210b, 222b of members 210, 222 of panel 200.
[0012] The welding w between members 210, 222, 224 and 226 of panels 200 and 202 is illustrated by short hatch lines. Other welding w in panels 200 and 202 is similarly illustrated.
[0013] The top panel 202 has a second robust flat member 226 (Fig. 17) welded at w to the underneath of the base element 210a of the lowermost horizontal member 210 of the top panel 202. A portion 226a of flat member 226 of top panel 202 projects forwardly of the front face 202A of top panel 202, that is, forwardly of the vertical elements 210b, 222b of members 210, 222 of panel 202.
[0014] The base panel 200 has a nose assembly 204, welded at w to the underneath of the base element 210a of the lowermost horizontal member 210 of the base panel 200. The nose assembly 204 (Figs. 12 and 13) is formed by an elongate member 227, a robust nose bar 230, triangular stiffeners 233, end-plates 235 (shown in Figs. 7 and 11, omitted in Figs. 12 and 13) and a back-plate 241.
[0015] The horizontal C-section and box-section members 210, 222 of the base and top panels 200, 202 are all of a uniform length and are longitudinally staggered so as to leave spaces 234 (Figs. 1, 6 and 21) between the ends of alternate C-section and box-section members 210, 222 at each side edge 200C, 202C of each panel 200, 202, for a purpose described below. Except for the spaces 234, members 210 and 222 are welded together at w continuously along their entire lengths on both faces 200A (202A) and 200B (202B).
[0016] Two vertical, robust angle-members 236 and two vertical, flat members 238 are welded, at the two side edges 200C of panel 200, to the ends of the horizontal C-section and box-section members 210, 222 of the base panel 200, so as to seal the ends of horizontal cavities 220 inside the C-section and box-section members 210, 222 against the intrusion of water, which would otherwise corrode the members and which would also otherwise add considerably to the weight of the panel 200.
[0017] Similarly, two angle members 237 and two flat members 239 are welded to the ends of members 210, 222 of the top panel 202 at its two side edges 202C. Fig. 15 shows, with respect to the top panel 202, the sealing in this way of the cavity 220 of one C-section member 210 of the top panel 202. The sealing of all the cavities 220 in members 210 and 222 of panels 200 and 202 is effected in the same manner.
[0018] Each angle member 236 (237) has one wider element 236a (237a) and one, perpendicular, narrower element 236b (237b). The wider element 236a (237a) covers parts of the members 210, 222 on the front face 200A (202A), whilst the narrower element 236b (237b) extends across the side edges 200C (202C) from the front face 200A (202A) to the back face 200B (202B). Each flat member 238 (239) covers parts of the members 210, 222 on the rear face 200B (202B). Each flat member 238 (239) extends from, and is sealingly welded at w to, a distal edge of the narrower element 236b (237b) of angle-member 236 (237) and faces the wider element 236a (237a) thereof, as shown in Fig. 14 for members 237 and 239.
[0019] The strength of the panel 200 (202) is enhanced by the fact that some of the welds w between the C-section and box-section members 210, 222, on the one hand and the vertical angle members 236 (237) on the other hand are substantial welds in the spaces 234 between the alternate C-section and box-section members 210, 222 as shown.
[0020] Two end-posts 206, 206 are welded to the rear face 200B of the base panel 200 and two similar end-posts 207, 207 are welded to the rear face 202B of the top panel 202. Each end-post 206 (207) comprises two vertical flat members 228, 230 (229, 231) projecting perpendicularly from, and welded at w to, the respective flat member 238 (239), with strengthening webs 243 (245) extending between and welded to the members 228, 230 (229, 231).
[0021] A pair of upper strut-connectors 500b and a pair of lower strut-connectors 500b are secured by bolts and/or welding to the end-posts 206 at the rear face 200B of the base panel sub-assembly 200/5 and a single pair of strut-connectors 500b are similarly secured to the end-posts 207 at the rear face 202B of the top panel 202. Each strut-connector 500b fits between the vertical members 228, 230 (229, 231) of the end-posts 206 (207). The strut-connectors 500b are each designed to be connected to the adjacent end of the respective strut 400 so as to allow the strut to push and pull the base panel or top panel respectively and also to allow the strut to pivot universally, relative to the base panel 200 or top panel 202, up to 5° from the vertical in any direction.
[0022] Additionally, leaf-spring end-connectors 214 are welded to the end-posts 206 (207) between the members 228, 230 (229, 231), for connecting the panel 200 (202) to the struts 400 via leaf-springs. Each leaf-spring end-connector 214 comprises a part-cylindrical portion 214a and a lateral web 214b, welded to each other and to the end-post members 228, 230 (229, 231) and to the vertical flat member 238 (239) of the panel 200 (202). The part-cylindrical portion 214a is cylindrical except for a slot 214c, either at the top of portion 214a to receive the bottom end of a leaf-spring, or at the bottom of portion 214a to receive the top end of a leaf-spring, the leaf-spring extending substantially vertically in either case from a strut 400.
[0023] The panel-securing means 316 (Figs. 14 to 16) comprises, firstly, two elements 340, each welded at w to, and extending between, the tops of members 228, 230 of a respective one of the two end-posts 206 of base panel 200. Secondly, the panel-securing means 316 comprises two elements 342, each welded at w to, and extending between, the bottoms of members 229, 231 of a respective one of the two end-posts 207 of the top panel 202.
[0024] Thirdly, the panel-securing means 316 comprises a horizontal, generally elongate spacer member 360, two nuts 344 and two bolts 346. An elongate spacer element 361 of member 360 extends between and is abutted by the flat member 226 at the top of base panel 200 and by the flat member 226 at the bottom of top panel 202 so as to space flat members 224 and 226 apart. A flat element 362 is welded to the inside end face of spacer element 361 and is abutted by inside edges of flat members 226, 226 as shown in Fig. 14. A horizontal, elongate, channeled clip member 364 is bolted to spacer element 361 by bolts 366 at intervals therealong. Lower and upper wings 364a and 364b of clip member 364 abut the front faces 200A and 202A of base panel 200 and of top panel 202 respectively, whilst the portions 226a, 226a (which project forwardly of the faces 200A, 202A, see above) of flat members 226, 226 of panels 200, 202 respectively are received in a channel 364c of clip member 364, between wings 364a, 364b.
[0025] The spacer member 360 also comprises two generally elbow-shaped elements 363, welded to spacer element 361 near the ends thereof and projecting laterally thereof. Each elbow-shaped element 363 extends between, and is abutted by, a respective pair of the elements 340, 342, being clamped therebetween by a nut-and-bolt 344, 346.
[0026] The panel-positioning means 318 comprises two pegs 348, each welded at w to the members 229, 231 of a respective one of the two end-posts 207 of top panel 202 and poking down between the members 228, 230 of end-posts 206 of base panel 200. More particularly, each peg 348 comprises two spaced-apart peg-elements 348a, 348a connected together by a web 348b, which is welded to them both at w as shown in Figs. 17 and 19. Upper portions 348c of peg-elements 348a are welded at w to members 229, 231 respectively. Lower portions 348d of peg-elements 348a are relieved on their faces at 348e and also formed with tapered edges at 348f, to facilitate entry between members 228, 230 of end-posts 206.
[0027] The pegs 348 are located, at shown in Fig. 14, between the elements 340, 342 of the panel-securing means 316 on the one hand and the vertical flat members 238, 239 of panels 200, 202 on the other hand.
[0028] The method of making each base panel 200 and top panel 202 is described in the specification No. of patent application No. 90 entitled "TRENCH-BOX PANEL" - reference 799P57729.
[0029] Fig. 22 shows the trench-box SB in an excavation in which a pipe P is being, or has been, laid. Whereas the top panels 202 are interconnected by the usual single pair of struts 400, the base panels 200 also are only interconnected with each other by a single pair of struts 400, these being near the tops of the base panels 200, leaving ample space underneath for the pipe P. It will be appreciated that the pressure of the earth walls of the excavation upon the base panels 200 results in very great leverage being exerted upon the connection between each base panel 200 and the corresponding top panel 202. The clip member 364, by the engagement of flat members 224, 226 in channel 364c, holds the base panel 200 outwardly against the excavation wall and prevents base panel 200 from folding inwardly relative to the top panel 202 about its connection thereto. The pressure of the excavation wall on the clip member 364 helps to hold the clip member 364 onto panels 200, 202.
1. A trench-box panel assembly comprising a pair of lower panels (200) and a pair
of upper panels (202), each upper panel (202) being mounted above a respective one
of the lower panels (200), a horizontal bottom edge of each upper panel (202) being
connected to a horizontal top edge of the respective lower panel (200) by an elongate
horizontal clip member (346) which extends along the edges (224, 226) of both panels
(200, 202) on the outsides of the panels and which interlocks therewith to restrain
mutual separation of the edges on the outsides of the panels, and adjustable struts
(400) extending between the pair of lower panels (200) and between the pair of upper
panels (202).
2. An assembly as claimed in claim 1, wherein the struts (400) extending between the
lower panels (200) are near the tops of the lower panels (200), leaving a strut-free
space between bottom halves of the lower panels (200).
3. An assembly as claimed in claim 1 or 2, wherein two wings (364a. 364b) of each
clip member (364) abut front faces of the respective upper and lower panels (200,
202).
4. An assembly as claimed in claim 3, wherein portions of flat members (224, 226)
are received in a channel between said two wings (364a, 364b), said flat members (224,
226) being located at said edges of said panels (200, 202) and welded to other parts
of said panels.
5. An assembly as claimed in any preceding claim, wherein each clip member (364) is
secured to an elongate spacer member (360) extending between the respective upper
and lower panels.