Not applicable.
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Not applicable.
While on a jobsite I witnessed a problem that persists between many other jobsites. Workers and equipment must travel through and work within foundations after the grade beams are dug. This presents a mobility problem. The equipment is needed to haul things into the areas where workers are present, or to dig and backfill trenches for utilities. There are cases when the grade beams are poured and there is then rebar that sticks out of the concrete. Rebar is bent and tied into shapes that have been designed and approved by structural engineers. It must maintain its proper shape. In these cases, the rebar gets smashed down by equipment tracking over it to get where it is needed. The rebar is then required to be repaired. This repair work is in excess of what contractors bid for and budget for when it comes to labor hours. If there were something, they could use to cross over these grade beams without ruining them it would prevent a lot of wasted capital and time. This something should be strong enough to carry the weight of equipment and people.
Based upon the problem outlined in section [005], I decided that the simplest solution would be to design a tiny lightweight bridge that could be moved around to different positions within a slab work area. This would not be too difficult a task using standard structural shapes. Since it needs to be portable and compact, I decided to use a truss design. To further reduce the weight, I decided to use aluminum extrusions as the material of construction. Based on my experience I decided that I would design one standard version for a specific weight load that would cover most applications. If a customer needs something stronger it will need to be engineered and built for their specific need. Customers may also use the invention for crossing other things such as small ditches, pipes, and electrical lines so long as they fit under the Jobridge, in the designated pass through for obstacles, without touching it. It shall have a rectangular section through the center that is open for pass through of obstacles.
The Jobridge is a new invention that is intended to make moving light equipment, such as skid steers and miniature excavators, within a foundation work site easier. By using a Jobridge, a contractor can effectively reduce or eliminate damage to the foundation grade beam trenches, steel reinforcements, plumbing, and electrical conduits. This will prevent the contractor from having to spend time and money they did not budget for on repairs. It is called the Jobridge because it behaves like a tiny bridge and is used on jobsites.
There is but one similar product that I am aware of. It is called the “Brahman System(s).” However, the scope of use is different. The Brahman is a device used in road crossings when there are hoses or electrical wires going over the road during construction or temporary re-routes of fluids or electricity. It is made from steel and is rated for much heavier loads. The Brahman cannot accomplish what the Jobridge can on a construction site. With a Jobridge a piece of equipment can cross over form boards without having to remove them. Then a mini excavator could be used to lift the Jobridge and move it to another place inside the forms where the equipment needs to cross over another obstacle. The Jobridge allows small equipment to play leapfrog with obstructions on a job site, primarily with new foundation construction phases. The Brahman has a small trough going through the center with a lid for the hoses or electrical wires to pass through it. The Jobridge has a raised center section allowing obstructions to pass under it or for the Jobridge to be placed over the obstruction.
To fabricate the Jobridge, one will need a welding table or jig that is flat, level with grade, and square. The table will need to be at least 8 feet in length or width. One will also need a welding machine that is capable of welding aluminum. The craftsman will also need tools to measure, level, cut, clamp, sand, and grind the work pieces. Once fabricated the Jobridge will need to be put in a spray booth and coated with a rubberized non-slip coating that is safety yellow in color. This is not meant to be an exhaustive list of tools and equipment, but more of an advisory that the Jobridge should be fabricated by skilled professionals that have this equipment and use it regularly.
The fabrication will need to start with building the four trusses. I will describe assembly of one truss, and this will be applicable to all four. Start with two aluminum 6061 T6 AISC C3×3.5 33 in long. Place them with the open side down on the work surface. They must be parallel to each other and the inside ends must be 30 in apart. This is shown in
Then, on each c-channel add the vertical members 11, 10, 9, and 8. There will be two of each, one for each side. These members are aluminum 6061 T6 AISC 2×1.5×3/6 rectangular tubes. Their locations can be seen in
Now add member 12 between the two, vertical member 8s. Member 12 is made from the same rectangular tubing as the member 8s and is 30 in long. Member 12 must be squared and held 90° from the member 8s. Member 12 must also be held flush with the tallest edge of the member 8s. Member 12 is to be welded on each end to the member 8s with full penetration welds.
Installing the two, part 14s may seem intimidating, however it is not difficult. Part 14 is an AISC L 1.5×1.5×3/16 6061 T6 aluminum angle. Use the cut length provided in the table to cut the pieces. To figure the angle cuts you will place them on top of the member 12 and 8s. Position them so that they are 20° from the horizontal member 12. Mark the angles you need to cut to make the pieces fit. Now weld them on each end. One end to member (part) 12 and one end to part 8.
A similar process will be used to install the two, part 13s. Part 13 is an AISC L 2.5×1.5×3/16 6061 T6 aluminum angle. Cut the two pieces to the length shown. Place them such that the inside surfaces are contacting all of the vertical tubes. The end that is over part 8 will need to be flush to the edge of part 8 that is welded to part 14. Mark the angles needed on each end of the part 13s. The angle on the end contacting part 7 should be a 20° angle as measured from the inside surface of the short leg of the L shape. See
Next install parts 15, 16, 17, and 18. There are 2 of each. The cut lengths of each are shown in the parts list. These parts are all AISC L 1.5×1.5×3/16 6061 T6 aluminum angles. These parts will complete the truss by adding reinforcement to the vertical members. In a process similar to the other angled pieces, place them on top of the space you will put them. They will partially rest on top of the vertical members, part 13 and part 7. The ends will need to go from corner to corner diagonally, or as close as they will reach. Mark the angles that need to be cut on the ends. For part 18, the piece will go from the corner of where part 11 meets part 7 to the center of that section of part 13. These pieces will be welded to the vertical members, part 7, and part 13 where they touch respectively. The welds shall be full penetration where possible, but otherwise they will be fillet welds.
Once 4 trusses have been made, it is time to begin building the overall assembly. Stand the 4 trusses up vertically such that they are resting on both sides of the c channels as shown in
There are 11 more, part 2s. These will be welded across the top of the trusses. They will all be parallel with each other and perpendicular to the trusses. The locations are shown in
Once the part 2s are done add the part 5s. Each part 5 is welded to the underside of the part 2s attached to parts 12 and 13. They are located between the trusses and also weld to the trusses. This can be seen in
Now parts 3 and 4 can be added. There is one, part 3 and two, part 4s. Part 3 can be seen in
Part 6 is the last part to be added on. The two, part 6s are the lifting lugs. It can be seen in
The last step in construction is the coating. The Jobridge is to be painted safety yellow with a high durability coating. The top surfaces shall be coated in safety yellow rubberized coating such as Line-X, Rhino Liner, or equivalent. Striping with black chevrons is also acceptable.
To use the Jobridge, one will need a mini excavator or skid steer weighing 12,000 lbs or less. If using a skid steer, it must have forks or another attachment for lifting things. The outside dimension of the tracks or tires must be 8 ft or less. The excavator or skid steer will be referred to as “the equipment” or “equipment.” Use the lifting lugs to attach the rigging of your choice. It may be nylon straps, cables, chains, or ropes. Attach the rigging to the bucket of the mini excavator or the lifting point on the skid steer attachment. Use the equipment to lift the Jobridge. Track over to the obstacle that you need to cross. Slowly lower the Jobridge over the top of the obstacle until it is contacting the ground on both sides of the obstacle. Detach the rigging from the equipment and the Jobridge. Track over the Jobridge with the equipment carefully, making sure not to go off the edge of the Jobridge. Once the equipment is on the other side of the obstacle and no longer contacting the Jobridge, it can be rigged for lifting again and either moved out of the way or used again to cross another obstacle.
Notice: There is a risk for equipment roll over while using this product. The user assumes all responsibility for damage to equipment, injury, or death in the use of the Jobridge. A properly sized piece of equipment will reduce the chance of this happening. Further reduction to risk will be achieved by using a competent, trained, and certified operator. The use of a flag man is highly recommended while using the Jobridge.