2000 NOVA Award Winners

Rapid Deployment Crane Barge
Lock-Up Device for Dynamic Loads
Mobile Parapet for Unguarded Roof Edges
Friction Pendulum Seismic Isolation
Steel-Free Concrete Bridge Decks

2000 NOVA Award Finalist

Steel Curve Guides for Steel & Wood Studs

NOVA AWARD WINNER

Rapid Deployment Crane Barge
The Rapid Deployment Barge (RDB) is an integrated barge and crane that is transported overland as a single trailer unit without disassembly. The barge’s most obvious and innovative feature is its fold ability for mobilization/demobilization and transport. 
      Individually sealed compartments form the 4' deep by 12' wide by 40' long center hull. Attached to each of its two sides by hinges are additional 4' x 4' flotation sections, each of individually sealed compartments. Mounted on the center hull deck is a John Deere 490 hydraulic backhoe/ excavator/ crane. With its multiple boom tips, the crane is the prime construction tool during construction operations, and it is the prime assembly/disassembly tool during mobilization and demobilization. 
     In operation, it is a 20' by 40' shallow draft barge with an integrated backhoe/ crane for pile driving, dredging, and other river and lake marine construction tasks. For transport between projects, the side flotation sections fold up and ride on top of the center hull. A  3-axle wheel assembly is attached to its stern, and the barge becomes a 12' by 40' trailer that is easily towed by any semi-tractor on regular roads and highways without special permit.      
     The barge was designed and fabricated from the ground up as a self-contained rapid deployment barge that provides an integrated set of marine construction tools that are particularly practical and efficient for small projects. Its owner reports that it reduces mobilization and transport costs by 75% of labor and 85% of cost, and it has opened new markets in light marine construction.

Contact: Trident Dock & Dredge, Inc.
204 Church St.
P. O. Box 899
Watervliet, Michigan 49098
Phone: 616-463-4072
Fax:      616-463-8874

Folded for Transport

Overland Transport

Driving Piles

Pulling Piles

Mechanical Dredge

Mr. Schmitt 
(click figures to enlarge)

Lock-Up Device
The Lock-up Device (LUD) is a temporary rigid link between a bridge deck and its supporting abutments and piers. Fast acting and short duration forces, such as seismic or truck or train braking or collision, are transferred to and shared among the supports. But the LUD moves with the bridge deck under slow acting forces from thermal, shrinkage, or creep. The LUD is used in new structures and strengthening existing bridge substructures, especially in seismic retrofitting. 
     The LUD is a piston-in-cylinder device similar to a large damper (like a shock absorber in a car). The space inside the cylinder (not occupied by the piston) is sealed and filled with a special compound. Piston diameter is slightly smaller than the inside diameter of the cylinder creating an annular space between them. This annular space allows the compound to squeeze its way through and flow from the cylindrical space in front of the piston to the cylindrical space behind the piston and vice versa, which permits the piston to slide back and forth inside the cylinder. The physical properties of the compound and the design of the LUD make this type of back-and-forth piston travel possible only for slow-acting phenomena such as the expansion and contraction of structural members due to changes in ambient temperature.
     When the LUD is subjected to fast-acting forces such earthquakes, it locks up (the piston does not slide within the cylinder) and the device acts like a rigid body. Unlike a shock absorber, the LUD absorbs no energy; instead it transmits sudden loads between its ends.

Contact: Colebrand Advanced Engineering
18-20 Warwick St.; Regent St.
London, England
Phone: +44 171 439 1000
Fax:     +44 171 432 0171 
or 
2401 Pennsylvania Ave. N.W.; Suite 604
Washington, DC 20037
Phone: 202-496-1654
Fax:     202-496-1656.
Website: www.colebrand.com
Email: adeng@colebrand.com

Mekong River Road
  Bridge, Thailand

Applications

Mr. Townsend and Mr. Bromage 
(click figures to enlarge)

Mobile Parapet for Unguarded Edges
The Mobile Parapet Barrier is a rolling guardrail that provides fall protection to construction and maintenance workers near edges of flat roofs. The Barrier is 8' square with four hard rubber casters. It is easily folded for transportation, and easily set up into its locked, open position. Assembly or disassembly takes less than a minute. Workers set up the Barrier well back from the roof edge where fall protection is not required, and "walk" or roll the Barrier from inside the safe (and legal) confines of the Barrier to the work site near the roof edge.
     Mobile Parapet Barriers are used exclusively on General Motors Corporation facilities, which includes many buildings throughout the country. The Barriers are so inexpensive they are left on the roof of some large facilities rather than dealing with transportation and hoisting. The Barrier has protected workers cleaning clogged roof drains, servicing perimeter light fixtures, changing filters in exhaust stacks, hoisting and lowering materials, and signaling crane operators
     The Barrier requires at least a 4" high parapet. Two 50-pound detachable counterweights at each of the two corners away from the roof edge resist overturning. Height, post, and midrail spacing comply with OSHA. Railings and posts safely resist a 200-pound load plus safety factor in any direction at any location on either front or side panels. 

Contact: Arthur M. Schlachter, P.E.
Worldwide Facilities Group
General Motors Corp.
485 W. Milwaukee Ave.
Detroit, Michigan 48202
Phone: 313 556-2562
Fax:     313-974-8784.

Mr. Schlachter 
(click figures to enlarge)

Friction Pendulum Seismic Isolation
Friction Pendulum Seismic Isolation Bearings isolate buildings or structures from ground motion during the earthquake. They use the characteristics of a pendulum to “swing and return” to absorb the energy and allow the ground to shake without damaging the structure. Attached to columns or foundation, these bearings support the loads of a structure and allow it to move sideways during the earthquake.
     The patented technology has been applied to seismic retrofitting and new construction on 26 projects with total project volume of $1.6 billion including some of the world’s largest seismically isolated buildings, bridges, and industrial tanks. They are less expensive to install than elastomeric bearings, and they are effective and economical for small buildings and chemical tanks. For retrofitting, the bearings allows the designer and contractor to keep the original structure without having to add shear supports to walls, columns, and connections, which, in many cases, are costly, difficult, and undesirable. Adding the bearings at the base minimizes the need to modify the shape and appearance, while providing protection against the earthquake.For new construction, the bearings increase the reliability and safety of a facility that may save not only repair costs and lives but can also maintain mission-critical functions.

Contact: Dr. Victor Zayas
Earthquake Protection Systems, Inc.
2801 Giant Hwy., Bldg. A
Richmond, California 94806
Phone: 510-232-5993
Fax:     510-232-6577.

Operation

San Francisco Airport

Hayward City Hall

Dr. Zayas 
(click figures to enlarge)

Steel-Free Concrete Bridge Deck
Steel-free concrete replaces reinforced concrete in bridge decks and similar structures in marine environments and in northern climates having snow and ice. Its main benefit is elimination of the source of deterioration, the steel reinforcing bars in slabs exposed to deicing salts. Eliminating corrosion makes concrete deck slabs virtually maintenance-free, which makes life cycle costs of steel-free concrete decks much lower than reinforced concrete decks.
    Shear connectors make the steel-free concrete deck composite with the steel girders that support it. Top flanges of girders attempt to displace outward when a truck drives across the deck. External transverse steel straps below the bridge deck and between the bridge girders prevent this outward displacement by providing a lateral restraining force to the girder and concrete deck. In response, compressive membrane forces develop in the concrete deck. Ultimate load can be greater than the load at which the same deck would fail if it were reinforced conventionally. In fact, the tension capacity of the steel straps in the steel-free deck replaces conventional reinforcing steel. The external steel straps can be inspected and maintained in a similar fashion to steel girders.

Contact: Dr. Aftab A. Mufti, P.Eng.
Nova Scotia CAD/CAM Centre
Dalhousie University
P. O. Box 1000
Halifax, Nova Scotia B3J 2X4; Canada
Phone: 902- 494-6035
Fax:     902-422-8380
Email: cad.cam@dal.ca.

Salmon River Bridge



Cross-Section
 
Chatham Bridge

Dr. Bakht, Dr. Mufti, and Dr. Jaeger 
(click figures to enlarge)

Steel Curve Guides for Stud Walls
Flex-C Trac (FCT) is a segmented, pivoted track for framing curved walls, columns, arches, S curves, and irregular and compound curves vertically or horizontally using standard channel and stud construction. FCT is a segmented, ten-foot long U-channel shaped piece of sheet metal with a metal strap threaded through each side of the U-channel. Segments are pivotally connected, allowing the channel to be shaped easily by hand to match any desired curve. Self-drilling screws are installed into the sides of the channel, through the metal strap to make the curved channel rigid and ready for installation. 
     For a curved wall, one curved piece of FCT is fastened to the floor and a mirror image curved piece is fastened to the ceiling, using conventional nails, screws, or powder-actuated fasteners. Next, typical metal or wood studs are inserted into the U-shaped channel of the FCT, between the top and bottom sections. The assembled frame is then covered with normal wall coverings such as gypsum board, flexible wallboards, wood, or lath and plaster. A curved ceiling simply requires that the assembly method be implemented sideways. 

Contact: Franklin L. Wheeler
Flex-Ability Concepts
P. O. Box 7145
Edmond, Oklahoma 73083
Phone: 405-302-0611
Fax:     405-302-0645.

(click figures to enlarge)

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This page written 05/02/2000 by RICarr