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What is Tru-Frame®?

Tru-Frame is a revolutionary cost-saving "special truss moment frame" system.

Cost Savings

One of the most exciting aspects of this system is the dramatic cost savings to material, shop fabrication and erection.

  • Material & Shop Fabrication Savings

    On the material side, we are utilizing the fact that an open web steel joist typically weighs about 20% less than a wideflange beam capable of carrying the same gravity loads. In addition to the weight savings is the fact that fabrication costs for open web framing are about 20% less than fabrication cost of wideflange beams.

    As an example:

    • 100 tons of wideflange framing x $1,200/ton = $120,000
    • 80 tons of open web framing x $1,000/ton = $80,000
    • Net Savings = $40,000

    The combination of less weight per square foot of building area and less cost per pound can produce overall savings of the material by as much as 30%.

  • Erection Savings

    The field labor savings are even more dramatic. As a result of the Northridge Earthquake, new codes have been implemented by U.B.C. that require conventional moment frames to have additional requirements such as cover plates added at all flange-to-column connections.

    Sketch 'A' showing full-penetration and fillet welds.As you can see in sketch on the left, this substantially increases the quantity of weld passes required to complete the full penetration weld. On some projects such as hospitals or municipal buildings, inspection procedures require cool down, ultrasonic testing and preheat between every pass, requiring days to complete one connection.

    Sketch 'B' showing bolted connections.The Tru-Frame connection shown in the sketch to the right requires only a simple bolted detail at the top chord and a single pass fillet weld at the bottom chord without preheat or ultrasonic testing, reducing the labor costs as much as 90%. This is achieved by moving the inelastic deformation to a special link element at the midspan of the truss.

    The combination of material, shop fabrication savings and erection savings can produce a cost reduction in the range of $5.00 per square foot.

Time Savings

There are multiple areas where time is saved by the use of this system:

  • Design

    Shop drawing time is dramatically reduced since the drawings are prepared in conjunction with the development of the contract documents. This can save on the average of four to six weeks in the overall schedule.

  • Fabrication

    Fabrication time is cut in half for open web framing versus conventional wideflange frames due to the split responsibility between the steel fabricator just providing the columns and the joist manufacturer fabricating all the horizontal framing. Considering the average capacity of our joist manufacturer is about 300 tons per day our fabrication durations are measured in days rather than weeks.

  • Erection

    Erection time savings can vary based on quantity and size of frames along with inspection requirements. The minimum savings should be 20% with a potential reduction of as much as 70% if inspection is requiring ultrasonic testing of each pass of a wideflange moment connection. On a standard commercial office building of approximately 100,000 square feet there would be at least a two week reduction in the erection schedule.

Reduced Footings

As a result of reducing the overall structure weight, by as much as 35%, there will be a reduction in base shear requirement and footing size. This saves costs in excavation, reinforcing, and concrete.

Inspection

The standard moment frame design requires 100% visual inspection and ultrasonic testing which is eliminated when using the Tru-Frame® system. Since all the Tru-Frame® connections are either "Tension Control" bolts or single pass fillet welds they can be visually inspected any time after completion without need for additional testing.

UBC & IBC Approval

A supplement to the 1994 Uniform Building Code, the Special Truss Moment Frame is now incorporated into the 1997 Edition. Design provisions for the "Special Truss Moment Frame" have also been incorporated into the 2000 International Building Code.

System Comparison Chart

  Moment Frame Brace Frame Tru-Frame®
COST Steel (lbs per sq. ft.) Good Better Best
Fabrication Speed Good Better Best
Erection Speed Good Better Best
Fabrication Steel Cost Good Better Best
Engineering Cost Better Better Best
Fireproofing Cost Best Better Good
Inspection Cost Good Better Best
TIME Detailing/Approval Good Better Best
Procurement Flexibility Good Better Best
Fabrication Good Better Best
Erection/Welding Good Better Best
Inspection Good Better Best
OTHER CONCERNS Bay Size/Span Better Good Best
Floor-to-floor Better Best Better
Building Height Better Best Better
Post-Earthquake Modification Good Better Best
Exterior Skin Options Best Best Best
Line-of-Sight Best Good Best