LARGE STRUT SYSTEM DOWNTOWN SAN FRANCISCO

Shimmick Construction, out of Oakland, CA, having worked with C. H. Bull in the past on bridge jobs and other high tonnage jacking jobs called us for a new application. C. H. Bull is known as a solutions company when it comes to high tonnage jacking and other areas like fall protection. Stan Sheppard, our in house jacking expert, worked with the Shimmick engineers to design a system to stress large diameter horizontal steel supports which were needed at three levels of the large foundation being excavated for a new building.

A unique application needing lateral forces not vertical forces on compression struts

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One of many large diameter pipes in place

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A second support pipe in place parallel to the first pipe set

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The two “wagon looking” items are custom jack cradles

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These struts had to handle a lot of force (up to 700 tons) because the excavation was surrounded by high rise buildings.

Custom jack cradles each holding two 350 ton jacks
And together applying 700 tons of force to the struts.

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Four (4) 355 ton jacks with 4” stroke, four (4) 660 ton jacks with 3” of stroke and four (4) 660 ton jacks with 6” of stroke were mounted into special jacking fixtures that fit around the pipe. These were designed so once the strut was jacked to the pre-determined force the struts could be secured in place and the jacking fixtures could be picked by a crane and moved to the next strut.

Two of the pumps used to extend the jacks. There we also a number of manifolds and 100’s of feet of hoses.

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C. H. Bull also supplied to the job all of the hydraulic hoses, manifolds, valves, gauges and two – 10 HP pumps with 20 gallon reservoirs.  All of the jacks where also calibrated to the gauges to insure accurate measurements of the forces applied. Stan Sheppard was at the job site consulting to assure the systems were being set up and operated correctly. This was another unique application where working with our customer we were able to engineer a successful solution.