1. Field of the invention
The present invention is generally directed to a system for temporarily shoring up an excavation site. More particularly the invention is directed to a reinforcing assembly for a corner connection used in a reinforcing arrangement that supports sheet piling in an excavation site.
2. Description of the Prior Art
In a typical excavation site, workers are exposed to numerous hazards. The most common hazard is having the walls of the excavation site cave in on the workers, thus causing serious injury. Often due to soil conditions and wetness, the sides of a construction site will simply collapse. Water is a particularly dangerous hazard because it is so heavy and can destroy shoring, which has not been properly reinforced. Realizing this problem the government, at both the federal and state level, has set up specific requirements for all excavation sites to avoid the problem of cave-ins. For example the United States Department of Labor and, more specifically, the Occupational Safety and Health Administration (OSHA) requires that excavation sites be prepared with some type of shoring. Additionally many companies are now aware of the problems involved in a typical excavation site and have developed internal policies requiring shoring for any excavations they contract to have completed.
A good example of a typical excavation project is found in replacing underground storage tanks for a gasoline station. Typically, in such an operation, sheet piling is pounded into the ground in a generally rectangular configuration around the work site. The piling has to be driven extremely deeply into the ground and arranged to provide sufficient support against potential cave-ins. Typically the sheet piling has to be driven so deep that half its total height remains underground after the excavation has been completed. Use of such large amounts of material is quite expensive. After the sheet piling has been installed, the workmen then remove the dirt and fill material from within the rectangular shoring. During the work of removing the old storage tanks and replacing them with new storage tanks the shoring provides protection to the workmen against potential cave-ins. Once the storage tank replacement operation has been completed the shoring can either be completely removed or simply cut down We to a safe distance below ground and then left in place. Such a method of shoring an excavation site is extremely expensive.
Various solutions have been proposed in an attempt to cut down on the costs of shoring an excavation site. For example U.S. Pat. No. 5,154,541 discloses a modular earth support system. Specifically, the patent teaches using panels placed around an excavation site and interlocked with one another to form a generally rectangular shoring configuration. Once the panels are in place, reinforcing beams are placed behind the panels to ensure the weight and force of the dirt behind the panels does not cause the panels to fail. The main drawback of using such a system is that standard I-beams cannot be used. Rather, special beams that are cut exactly to size and additionally have a customized end configuration must be used. Such beams are particularly expensive; especially considering a large number of beams of varying sizes would have to be kept available for differently sized excavation sites.
Another proposed solution to reducing the high cost of shoring excavation sites is found in U.S. Pat. No. 4,685,837. This patent proposes using panels as shoring members in an excavation site and uses laterally extending braces to reinforce the panels. The braces are connected to one another by a bracket. Alternatively, the braces maybe connected to each other by means of a connection in which one brace has a pair of tabs welded thereto with each tab having an aperture formed therein. The apertures align with a hole in a second brace and a pin is placed though the apertures to complete the connection. In either case there is no provision to adjust the length of the braces and connectors and they must be custom made for each different sized excavation site.
Numerous other proposed solutions are available including using wooden shoring which is a custom made to a particular excavation site. Such shoring is used only at the designated site and then disposed of. As a result this approach is prohibitively expensive. Also wooden shoring is not as durable as its metal counterparts. Often water along with regular wear and tear at the construction site can destroy the shoring during the construction job.
Perhaps the best solution proposed so far is set forth in U.S. Pat. No. 6,416,259 which is incorporated herein by reference. In that patent a corner connection for temporary shoring is shown as being used in an excavation site. Specifically, the corner connection is used to secure I-beams together at corners within the excavation site. Typically, four I-beams are connected together to form a rectangular frame that is suspended within the excavation for bracing the shoring walls thereof. The corner connection itself comprises mating socket or connecting members that are placed over the ends of I-beams to be fastened together. Some portions of this prior patent are summarized below in the discussion of
Turning now to
A double tab type connector 30 shown in
As can clearly be seen in
Turning now to
Essentially each box type connector 29′, 30′ has a box-like main body 40′, 70′ that has been lengthened along with its corresponding panels 50′, 51′, 55′, 56′, 80′, 81′, 85′, 86′ to provide room to support a pair of extra tabs 101, 102, 103, 104 each tab has an aperture (only two shown) 106, 108 formed therein. A reinforcing bar 120 having a tab 130, 131 located at each end is provided to reinforce the two box type connectors 29′, 30′. The tabs 130, 131 located at the end of reinforcing bar 120 each have an aperture (not shown) located therein which will cooperate and align with the apertures 106, 108, formed in the extra tabs 101, 102, 103, 104 of each box type connector 29′, 30′. A pin 100 may then be placed in the respective apertures once they are in proper alignment to hold the reinforcing bar 120 in place.
However even with this reinforcing bar 120 in place the maximum permissible load may be insufficient and the expense of using heavier materials is always a factor.
Based on the above, therefore there exists a need in the prior art of excavation shoring to provide a system wherein shoring can be provided at an excavation site in an inexpensive and reusable manner that does not suffer the disadvantages of the prior art discussed above. More specifically there exists in the art a need to provide a connector for interconnecting various beams used to reinforce shoring in a manner which may allow much greater loading than previously has been available but still uses the same parts as used in previous shoring systems.
Specifically, a corner connection used to secure I-beams together at corners within the excavation site is provided with a reinforcing assembly that allows for greater loads. Typically, four I-beams are connected together to form a rectangular frame that is suspended within the excavation for bracing the shoring walls thereof however; any polygonal shape may be used. The corner connection itself comprises mating socket or connecting members that are placed over the ends of I-beams to be fastened together.
One of the connecting members includes an outwardly extended tab while the other includes a pair of outwardly extended tabs. The first outwardly extending tab fits between the two extending tabs of the corresponding connecting member. All of the tabs are provided with apertures that are placed in alignment when the connection is made so that a bolt or pin can be passed through the apertures to secure the two connectors together. An additional set of tabs is provided on the connecting members that is also provided with apertures. A reinforcing assembly is provided and includes a reinforcing bar with tabs. A first spacer bar is attached to the reinforcing bar and one connecting member and a second spacer bar is attached to the reinforcing bar and an adjacent connecting member. The spacer bars, the reinforcing bar and the connection members are all connected with tab/pin connections. Advantageously the reinforcing assembly can use the existing second set of tabs located on the prior art connectors.
The socket members also include a large eyelet for receiving a chain or other elongated supporting member that is typically used to suspend the resulting I-beam frame at a desired height within the shoring walls.
Additional objects, features and advantages of the present invention will more readily be apparent from the following description of the preferred embodiment thereof, when taken in connection with the drawings wherein like reference numerals refer to correspond parts in the several views.
Referring now to
The panels of piling 219 have interlocking edges and thus can provide support for each other once they are in place. Also the panels 219 are formed in an undulating pattern for added strength. Typically such panels 219 are made of relatively thick and expensive sheet metal. It is important to note that using large quantities of such a sheet metal is extremely expensive. Furthermore, using prior shoring methods, the sheet metal was often left at the excavation site 205 at the conclusion of the construction job. As will be discussed more fully below, with the subject method, the amount of sheet piling 219 used is not only reduced, but less sheet piling 219 is required initially because the sheet piling 219 only has to extend as deep as the excavation hole 206.
A reinforcing structure 226 is provided behind the interlocking sheet piling 219. The reinforcing structure 226 includes the set of I-beams 220-223 that interact with the set of corner connections 211-214. Such a structure 226 is needed in order to prevent the sheet piling 219 from buckling under the weight of the earth surrounding the sheet piling 219. This is particularly true when the earth is wet or particularly loose. The corner connections 211-214 are designed to receive the ends of the I-beams 220-223 to form a rectangular structure. While a rectangular shape is shown here and is probably the most common configuration used it should be kept in mind that any polygonal configuration of three or more sides could be used and not depart from the spirit of the invention.
Under normal conditions the reinforcing structure 226 would simply be suspended by a chain or other mechanism (not shown) at a desired height within the excavation hole 206. If however, the sheet piling 219 starts to buckle under the weight of wet earth it will immediately engage with the reinforcing structure 226. As pressure is placed on the I-beams 220-223 and corner connections 211-214 they will only give a small distance before applying an enormous normal force that will stop the sheet piling 219 from any further buckling.
Turning now to
Optionally a gusset 262 is formed between the side panel 256 and the tab 232 for added strength. An additional gusset (not shown) may be formed between the tab 232 and the end panel 257. Preferably an eyelet 269 is formed on the top panel 250. The eyelet 269 is designed to receive a chain or other elongated supporting member (not shown) used to support the I-beams 220-223 and corner connections 211-214 at a desired height within the excavation hole 206. The eyelet 269 is completely optional as the chain could simply be placed around one of the I-beams 220-223 to provide support.
A double tab type connector 230 shown in
Optionally a gusset 292 is formed between the side panel 286 and the top tab 234 for added strength. Webs (not shown) may be formed between the two tabs 234, 236 in order to further increase their strength. An additional gusset (not shown) may be formed between the top tab 234 and the end panel 287. Preferably an eyelet 295 is formed on the top panel 280. The eyelet 295 is designed to receive a chain or other elongated supporting member (not shown) used to support the I-beams 220-223 and corner connections 211-214 at a desired height with the excavation site 205. The eyelet 295 is completely optional as the chain could simply be placed around the I-beams 220-223 to provide support.
As can clearly be seen in
As can best be seen in
The reinforcing assembly 330 includes a reinforcing bar 320, a first spacer bar 322 attached to the reinforcing bar 320 and the first shoring beam connector 229 and a second spacer bar 324 attached to the reinforcing bar 320 and the second shoring beam connector 230. The reinforcing bar 320 is formed of a standard I-beam that has had its ends cut at 45 degrees so as to form the overall temporary shoring 218 into a square configuration. As mentioned above other shapes and angles could be used. The reinforcing bar 320 will preferably be 8 feet or 12 feet long but other sizes may be used as desired. The spacer bars 322, 324 are simply rectangular flat pieces of steel. The spacer bars must be sized based on the length of the reinforcing bar 320 and the angle of the corner connection. As such this length is set by the geometry of the temporary shoring 218.
A first fastening assembly 335 includes the first tab 301 that extends laterally from the main body portion 240 of the first shoring connector 229. The first tab 301 has an aperture 306 located therein adapted to receive a first connecting pin 336. Optionally the first fastening assembly may also include the second tab 302 having aperture 307 aligned with aperture 306 and adapted to receive the first connecting pin 336. A second fastening assembly 340 includes the first tab 303 extending laterally from said main body portion 270 of the second shoring beam connector 230, and has aperture 309 located therein adapted to receive a second connecting pin 346. Optionally the second fastening assembly 340 may also include a second tab 304 having an aperture 309 aligned with the aperture 308 and adapted to receive second connecting the pin 346.
The reinforcing bar 320 further comprises a first tab 350 with an aperture 351 adapted to receive a third connecting pin 352 located at a first end 353 and a second tab 354 with an aperture 355 adapted to receive a fourth pin 356 located at a second end 357. Optionally third and fourth tabs 358, 359 may be added to the reinforcing bar 320 and be aligned with first and second tabs 350, 354 respectively.
The first spacer bar 322 further comprises an end 360 with an aperture 361 located therein adapted to receive the first connecting pin 336, a second end 363 with an aperture 364 located therein is adapted to receive the third pin 352. When the optional tabs 302, 358 of the first corner connector 229 and the reinforcing bar 320 are used, the ends 360, 363 of the spacer bar 332 will fit between the tabs 301, 302 of the first corner connector 229 and the tabs 350, 358 of the reinforcing bar 320.
The second spacer bar 324 further comprises a first end 370 with an aperture 371 located therein adapted to receive the second connecting pin 346. A second end 373 with an aperture 374 located therein is adapted to receive the fourth pin 356. When the optional tabs 304, 359 of the second corner connector 230 and the reinforcing bar 320 are used the respective ends 370, 373 of the spacer bar 324 will fit between the tabs 303, 304 of the second corner connector 230 and the tabs 354, 359 of the reinforcing bar 320.
The reinforcing bar 320 has a hook 380, 382 attached to each end 384, 386 and each said hook 380, 382 is adapted to be connected to a respective shoring beam 221, 220. The hooks 380, 382 are formed of a main plate 390, 391 welded to each end 384, 386 of the reinforcing bar 320 and an additional two smaller plates 394, 395, 396, 397 are welded to the main plates 390, 391 to form a hook configuration. The hooks 380, 382 mate with the top web of the respective I-beam shaped shoring beams 221, 220. Additional lower hooks 398, 399 may be mounted to the main plates 390, 391 but they are completely optional because the weight of the reinforcing bar 320 is sufficient to keep it in place.
In operation, typically the entire temporary shoring assembly 218 arrives on a truck. Initially the I-beams 220-223 are arranged in a rectangular or other polygonal shape around the perspective excavation site. Next the connectors 229, 230 such as shown in
First the reinforcing bar 320 is placed on the shoring beams 221, 220 so that the hooks 380, 382 seat on the top web (not separately labeled) of each shoring beam 221, 220. Next the spacer bars 322, 324 are placed so that the apertures 361, 364, 371, 374 on the first and second ends 360, 363; 370, 373 of each bar 322, 324 align with the appropriate apertures 306-309, 351, 355, of the corner connectors 229, 230 and reinforcing bar 320. At this point the optional lower hooks 398, 399 may be installed. The reinforcing structure 226 formed of the I-beams 220-223 and corner connections 211-214 now defines the edge of the excavation site 205. The sheet piling 219 is driven into the ground around the reinforcing structure 226.
Previously, the sheet piling 219 would have to be driven 2 ft. into the ground for every 1 ft. deep into the ground the excavation site 205 would extend. The cost of using so much sheet piling 219 is extremely expensive. With this new invention the sheet piling 219 need only extend slightly below the bottom of the excavation site 205.
Once the sheet piling 219 is in place, the dirt and other material within the excavation site's perimeter is then removed. The reinforcing structure 226 is then lowered to an appropriate height. The reinforcing structure 226 is held at that height by chains that extend to the eyelet on each box connector. It should be noted that the reinforcing structure 226 would not actually be under load until and if the sheet piling 219 starts to buckle under the load of dirt or water located behind a sheet piling 219. If the sheet piling 219 starts to buckle the corner connections 211-214 will take that load and be forced tighter unto their respective I-beams 220-223. Once any tolerance between the I-beams 220-223 and corner connections 211-214 is taken up the reinforcing structure 226 will then prevent any further movement of the sheet piling 219 and also prevent a cave in. When pressure is applied to the main I-beams 220-223 from the walls of the excavation hole 205 as they try to collapse the spacer bars 322, 324 keep the reinforcing bar 320 in place and stop it from moving away from the corner connection 211. The reinforcing bar 320 then takes most of the load, much more of a load than could be handled by the corner connection 211 on its own. Workers can then move about the excavation site 205 and safely perform whatever task is necessary. For example, the workers could remove old storage tanks (not shown) that may need removing and replace them with a new set of storage tanks (not shown). Additionally, other structures may be formed within the excavation site 205. For example a slab of concrete may be poured at the bottom of the excavation site 205 to aid in supporting storage tanks. Additionally, gravel or other fill material may be placed around the tanks as is needed. All the while, the workers will be safe from any potential cave in.
Once the excavation site 205 is ready to be refilled, typically a corner sheet of piling 219 is removed so as to enable the workers to remove the corner connections 211-214. Once one set of corner connectors is removed, the rest of the reinforcing structure 226 can easily be removed from the excavation site 205 and used again. One of the great benefits of the instant invention is that a much greater load can be supported by the overall temporary shoring 218. Additionally, with the use of the reinforcing assembly 330 even larger holes may be shored. Indeed holes with sides of up to 60 feet per side may be shored which much greater than can be shored without the reinforcement assembly 330.
Although described with respect to preferred embodiments of the invention, it should be understood that various changes and/or modifications could be made to the invention without departing from the spirit thereof. Therefore, the specific embodiments disclosed herein are to be considered illustrative and not restrictive. Instead, the invention is only intended to be limited by the scope of the following claims.