Design & Construction of Barrier Cable Systems Presented by: Carlos Banchik, P.E. Innova Technologies Inc.

Transcription

1 Design & Construction of Barrier Cable Systems Presented by: Carlos Banchik, P.E. Innova Technologies Inc. Co-Author: Peter Scoppa, P.E. Suncoast Post-Tension, Ltd.

2 Topics : Code Requirements (International Building Code (IBC) 2009) Design (Post Tensioning Manual 6 th Edition 2006, PTI & Technical Notes No.14, Design of Prestressed Cable Barrier Systems, 2004) Material Specifications Specification for Seven-Wire Prestressing Steel Strand for Barrier Cable Applications 2007 Stressing & Finishing Details Maintenance & Repair

3 Code Requirements: International Building Code (IBC) 2009 Chapter 4 Special Detailed Requirements Based on Use and Occupancy Pedestrian Protection Vehicular Restraint Section Pedestrian Guards shall comply with Vehicle guards shall comply with IBC and 1013 Section Vehicle Guards shall be 33 tall and shall comply with loads in

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5 Code Requirements: International Building Code (IBC) 2009 Chapters 10 and 16 Chapter 10- Means of Egress (Geometry) Chapter 16 Structural Design (Loads) Height Opening Size Pedestrian Loads Vehicle Impact Loads

6 Code Requirements: Chapter 10 Means of Egress (Geometry ) Section 1013: Guards Where Required. > 30 to floor or grade below Height. >= Opening Limitation. Typically 4 max.

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8 Code Requirements: Section 16 Structural Design (Loads) Section 1607: Live Loads Pedestrian Distributed 50 lbs/ft applied on any direction Pedestrian Concentrated 200 lbs applied on any direction Vehicle Concentrated 6,000 lbs horizontally 1 st Condition: 1-6 above floor 2 nd Condition: 2-3 above floor Assume load applied in1 sqft. If larger loads are expected, use them

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10 Design: Post Tensioning Manual 6 th Edition 2006, PTI & Technical Notes No.14, Design of Prestressed Cable Barrier Systems, 2004 Impact loads create cable loads/tensions Check Resultant tension in cables Transferring cable load to supporting members Check deflections Use intermediate anchors to limit deflections

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13 Impact loads create cable loads/tensions Check Resultant tension in cables T 2 EA MV = + L N F 2 e

14 Transferring cable load to supporting members

15 Check deflections Use intermediate anchors to limit deflections a Pl L = 8AE

16 Material Specifications:

17 Material Specifications: Type of Cable - diameter, grade Corrosion Protection - galvanizing, epoxy, other Anchorages - P-T style anchors, donuts and adjustable anchors

18 Stressing and Finishing: Stress to minimum of 3 kips - after losses (minimize sag to 1/4, increase for column spacing> 18 ) Back-stress all anchorages Seal back side of column Cut excess tendon tail Patch pocket or cap donut

19 Details:

20 Details Cont d Steel Bracket with Threaded Barrel Anchors

21 Details Cont d Surface Mounted Barrel Anchors Required to Avoid Heavy Column Reinforcing Round Bearing Washer Slide-On Cap

22 Details Cont d From the files of what NOT to do: Expansion Joint Columns Extend Through Joint?

23 Details Cont d Intermediate Anchorages Used to Reduce Deflection Barrel Anchor Round Bearing Washer

24 Details Cont d Bracket used on Intermediate Concrete Column Where Sleeve Holes Were Missed or Out of Alignment Bracket Bolted to Column

25 Details Cont d Bracket used on Intermediate Concrete Column Where Sleeve Holes Were Missed or Out of Alignment Attached Using Barrel Anchors

26 Details Cont d Bracket used on Intermediate Concrete Column Where ONE Sleeve Hole Was Missed or Out of Alignment Bracket Attached to Column Using Adjacent Cables and Barrel Anchors Anchor used to fix bracket to Column Anchor used for Missing Sleeve

27 Details Cont d Use of Fixed-End Grabbit Anchor to Fix Missing Sleeve Slotted Plates Used to Hide Threaded Shank

28 Details Cont d Cables Interrupted By Piping or other Obstructions Saddle Clamps Barrel Anchor Saddle Clamps can be used in this application provided that the interrupted cable is not used for vehicle impact, in which case barrel anchors that have been back-set should be used. Load must be recalculated.

29 Details Cont d Horizontal Spacing to Accommodate Vertical Drains/Piping

30 Details Cont d Vertical Light-Wall Application

31 Maintenance Repair Checking tension Repair of coatings Check gripper marks Pulled out cables Repair of corrosion protection adjustable anchors (grabbits) allow for retensioning Use qualified coat to verify backseating of wedges internally stressed grabbit assembly replacement of cable Used Qualified Coating

32 QUESTIONS? THANKS!