This invention relates to shoring devices for trenches and other open excavations employed in construction industry.
This invention relates to devices for shoring open excavations. The device includes a pair of shoring panels held vertically apart and parallel to each other against sidewalls of excavation by a pair of strutting assemblies. Each shoring panel has laterally, on either end, a vertical guide edge and lengthwise two identical cutting edges of triangular cross section. The cutting edges are inversely arranged one on the top and the other at the bottom of the panel and opposite relative to sidewall of excavation. The panel is therefore versatile and is used all ways, inside out or upside down. Each strutting assembly has a pair of vertical struts held against each other by at least one horizontal strut that is fastened by pin or bolts onto vertical struts. Each vertical strut is provided lengthwise with a circular guide channel encompassing the guide edge of shoring panel and interlocking with it, so that shoring panels slide independently from each other, while the strutting assembly can adjust different pipe culverts.
The components of this shoring device are assembled together during first stage of excavation, up to 4 ft. deep, and create altogether a two side wall box. Afterward, the panels are pushed down one at time and independently to each other as excavation progresses. If depth of excavation is superior to height of the panel, another such shoring device is stacked above the previous one. The removal from the ground of such shoring device is easier consisting of simply removing the strutting assemblies first and the panels afterward.
There are many shoring devices used for securing the walls of open excavations and the working space inside it. One type of such shoring devices, commonly called trench shields, have usually two panels held by individual spreaders pinned or bolted onto the extremities of each panel via flanges or fixed connectors. The panels are usually provided with a cutting edge at the bottom part to facilitate penetration into the ground. The majority of these devices are rigid in a sense that they do not allow relative movement between spreaders and panels and most of the time their installation is achieved after excavation.
Another type of shoring device, commonly called slide rail shoring system, has a plurality of pairs of opposite rails or supporting columns spaced along the trench so that each pair is supported by a strutting frame which slides within opposite rail supports. Each rail support is provided on either side with guide channels where edges of large shoring panels slide within so that every two adjacent rails are connected with at least one shoring panel. This type of shoring device is currently used in the construction projects despite aversion in costs, weight and structural damages during utilization.
Knowing shoring device that has panels sliding vertically within excavation without using vertical support columns is disclosed in U.S. Pat. No. 6,224,296 (Fukumori). This device uses two pairs of large shoring panels. The first pair of panels, which shores the upper part of trench pressing against the excavation walls, is fixed at ground level. The second pair of panels slides within first pair shoring thereby the lower part of excavation. Both pairs of panels are connected and use sets of rigging to control the installation and removal of this device. Such device perform poorly in deep excavation and requires accurate installation regarding the space between first pair of panels their parallelism, etc . . . . The removal of the panel is also associated with damages of guiding pair of panels.
U.S. Pat. Nos. 3,910,053 and 4,657,442 (Krings), Nos. 5,310,289 and 5,503,504 (Hess et al.), Nos. 6,164,874 (May) disclose various slide rail shoring system, all of them including multiple pairs of columns, spreader systems and large shoring panels. The support columns and the spreader systems used with these shoring systems are very heavy and are often hammered to push it down which often results with strong damages and heavy costs in maintenance.
Substantially, the intent of present invention is to provide a shoring device of type described above that allows shoring panels to slide independently to each other so that the device could be lowered progressively as excavation progresses while supporting the excavation walls.
Pursuing this objective and others that will be explicit subsequently, one important aspect of the present invention resides on design of a strutting assembly that slides vertically formolckingly along the guides of shoring panels accommodating different pipe culverts and securing the soils surrounding the excavation while shielding the working space inside it.
Another aspect of this invention is the introduction of a shoring panel having two identical cutting edges fixed lengthwise one on the top and the other at the bottom of the panel. Thus, each panel could be used upside down or inside out according to the need of the user. Yet stacking of such devices over each other is considerably simplified as the cutting edge of the upper panel is supported, vertically and horizontally, by the cutting edge of lower panel eliminating thereby the need of using heavy arches to support the load on upper panels. Moreover, a major aspect coming with this invention relates the removal of such shoring devices when stacked over each other. As the contact between bottom and upper panel is made along the inclined plan defined by the cutting edges, it is possible to remove the bottom panel first and the upper panel afterward by just lifting preliminary the strutting assembly on the upper panels.
The new features considered as characteristic for the invention are set forth in the appended claims. Other advantages of the invention will be appreciated in view of the following description and drawings.
Referring to the drawings where like numerals indicate like elements, various embodiments incorporating the new features of the present invention are illustrated. The shoring device has one pair of panels and one pair of strutting assemblies.
The figure
As shown in the
As shown in
As shown in
As shown in
As showing in the
While the invention is illustrated and described in a trenching application it is not intended to be limited to the details shown since some various modifications or structural changes would not change the basic structure and principle of present invention.