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Update of anchoring procedures for the ALS floor

Update of anchoring procedures for the ALS floor. 09/19/2007. Why now?. Retrofit of beamlines often replace equipment leaving behind abandoned shells/anchors/studs Review of HILTI Technical Guide and phone calls to HILTI highlighted some issues

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Update of anchoring procedures for the ALS floor

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  1. Update of anchoring procedures for the ALS floor 09/19/2007

  2. Why now? • Retrofit of beamlines often replace equipment leaving behind abandoned shells/anchors/studs • Review of HILTI Technical Guide and phone calls to HILTI highlighted some issues • Drawings for HDI anchor details often used in BOM were incorrect

  3. Non “Greenfield” installation • Removed old 4.0.2 switchyard assembly • Found ~40 cutoff studs or shells – • Eng. Note didn’t discuss this situation • 4” no-go zone for new shells was default • Concrete patch (which sounded hollow) filling in old wire trench under shield wall • Steel plate for shield door

  4. Hilti Information • Table for derating of HDI anchors • Copies for all • Will be added to new version of Engineering Note M7696 • Multiple derating factors are multiplicative • Abandoned shells / studs need minimum of 3 diameters (of loaded shell) clearance for loaded shell to be fully rated • Conversation with HILTI and testing done at HILTI • “Effect of Abandoned Holes on Capacity of Wedge Bolts”

  5. For ½” HDI shells, need 7” between loaded shells and 6” from edge to be fully rated. Between 4” and 7” (or 6”) there is a derating factor; below 4” isn’t allowed. Derating factors are per shell / edge and are multiplicative.

  6. Engineering Documentation • Engineering Note M7696 “Concrete Floor Anchor Applications” controls our work for installing equipment at the ALS. • Version A is most current but needs revisions based on the information presented here • Does not reference anchor detail drawings • Basic method for calculating seismic loads – uniform loading, symmetric, no derating • In Work Manager: • 26D412 : Anchor detail for HILTI ½” HDI • 26D409 : Anchor detail for HILTI HIS (epoxy) • Often are called out in BOM for installation drawings along with the Engineering Note M7696 • Current versions are incorrect; new versions are being made

  7. Seismic Calculations • Dave Plate has a spreadsheet for basic calculations – best place to start • For more complex situations (e.g. derated bolts) need to check all scenarios • Examples from MERLIN • Can have OSD calculate CG but need to have correct density for parts.

  8. New anchor Trench edge 2.13” 1.88” 6” (cutaway of floor) 4” What is rating of new ½” anchor for tension and shear during a seismic event? From Eng. Note: ½” HDI has a load of 2380 lbs in tension and 1780 lbs in shear. (takes into account 33% increase in load for short-term loading)

  9. 4” 6” 4” Note: Abandoned shell has no effect as 3x diameter away (1/2” HDI has .625” diameter) Load = 2380 lbs x .5 (for 4” a-a) x .83 (for 6” a-a) x .8 (for 4” a – e) = 790 lbs in tension = 1780 lbs x .5 (for 4” a-a) x .83 (for 6” a-a) x .65 (for 4” a – e) = 480 lbs in shear

  10. Takeaways • Use revised anchor detail drawings in BOM / drawing notes (let me know if you are using a different anchor detail). • If a new shell/anchor is placed too close to existing anchor (e.g. a utility pole or a stand for another beamline), must derate both anchors and recalculate seismic. • Careful of edges – concrete patches, trenches, steel plates in floor, etc.

  11. Takeaways cont. • Keep loaded ½” HDI anchors > 4” away from each other and edges at absolute minimum; 7” is necessary to be fully rated. • Stay > 2” away from abandoned shells- • Possible to core out abandoned shell / stud and grout – then need 1.5 diameters for fully rated. • Visit and revisit location to make sure everything is captured in your model – will save rework later • For installations in non-Greenfield areas, consider adding extra anchor holes in base.

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