barrier cable installation

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.


Topics : • Code Requirements (International Building Code (IBC) 2009)

• Design (Post – Tensioning Manual 6th 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


Code Requirements: International Building Code (IBC) 2009 Chapter 4 Special Detailed Requirements Based on Use and Occupancy

Pedestrian Protection

Section §406.2.3 Pedestrian Guards shall comply with §1013. Vehicle guards shall comply with IBC 406.2.4 and §1013

Vehicular Restraint

Section §406.2.4 Vehicle Guards shall be 33” tall and shall comply with loads in §1607.7.3


Code Requirements: International Building Code (IBC) 2009

Chapters 10 and 16

Chapter 10- Means of Egress (Geometry)

Height Opening Size

Chapter 16 – Structural Design (Loads)

Pedestrian Loads

Vehicle Impact Loads


Code Requirements:

Chapter 10 – Means of Egress (Geometry )

Section 1013: Guards

1013.1 Where Required. > 30” to floor or grade

below

1013.2 Height. >= 42”

1013.3 Opening Limitation.

Typically 4” max.


Code Requirements: Section 16 – Structural Design (Loads)

Section 1607: Live Loads

1607.7.1 Pedestrian Distributed 50 lbs/ft applied on any direction

1607.7.1.1 Pedestrian Concentrated

200 lbs applied on any direction

1607.7.3 Vehicle Concentrated 6,000 lbs horizontally 1st Condition: 1’-6” above floor 2nd Condition: 2’-3” above floor Assume load applied in1 sqft. If larger loads are expected, use them


Design: Post – Tensioning Manual 6th 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


22

eEA MVT FL N

= +

Impact loads create cable loads/tensions Check Resultant tension in cables

Design & Construction of Barrier Cable Systems Transferring cable load to supporting members


1

2 3

8Pl La

AE

=

Check deflections Use intermediate anchors to limit deflections


Material Specifications:


Material Specifications:

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


•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

Stressing and Finishing:


Details:

Design & Construction of Barrier Cable Systems Steel Bracket with Threaded Barrel Anchors

Details Cont’d

Design & Construction of Barrier Cable Systems Surface Mounted Barrel Anchors – Required to Avoid Heavy Column Reinforcing

Slide-On Cap

Round Bearing Washer

Details Cont’d


Expansion Joint Columns – Extend Through Joint?

Details Cont’d From the files of what NOT to do:


Intermediate Anchorages – Used to Reduce Deflection

Round Bearing Washer

Barrel Anchor

Details Cont’d

Design & Construction of Barrier Cable Systems Bracket used on Intermediate Concrete Column Where Sleeve Holes Were Missed or Out of Alignment – Bracket Bolted to Column

Details Cont’d


Bracket used on Intermediate Concrete Column Where Sleeve Holes Were Missed or Out of Alignment – Attached Using Barrel Anchors

Details Cont’d

Design & Construction of Barrier Cable Systems 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

Details Cont’d


Use of Fixed-End Grabbit Anchor to Fix Missing Sleeve

Slotted Plates Used to “Hide” Threaded Shank

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.

Details Cont’d

Horizontal Spacing to Accommodate Vertical Drains/Piping


Details Cont’d

Design & Construction of Barrier Cable Systems Vertical Light-Wall Application

Details Cont’d


Maintenance

Checking tension

adjustable anchors

(grabbits) allow for re-

tensioning

Repair of coatings

Use qualified coat

Check gripper marks

to verify back-seating of

wedges

Repair

Pulled out cables

internally stressed grabbit

assembly

replacement of cable

Repair of corrosion protection

Used Qualified Coating


QUESTIONS?

THANKS!

barrier cable installation

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