YIJUN ZHANG, Ph.D, PE
CABLE BRIDGE CONVEYOR, LLC. CONVEYOR DYNAMICS, INC. 1 CABLE BRIDGE CONVEYOR What Is It
. Conventional trough or pipe conveyor supported by suspension bridge. . The suspension bridge uses steel cables as main tension members to support loads. . Span of 200m~600m between supports are typical; longer span is also possible depending on wind conditions. . Suitable for crossing valleys, rivers, forests, structures and other difficult terrains, with minimal footprint and environmental impact.
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3 CABLE BRIDGE CONVEYOR Conveyor on Suspension Bridge
. Suspension bridges were built to support conveyors crossing Columbia river during hydropower dam construction in 1930s.
4 CABLE BRIDGE CONVEYOR Conveyor on Suspension Bridge
. Similkameen ore conveyor bridge in BC, Canada, built in 1980. . 404m span, 174m high truss tower; 1600 tph copper ore.
5 CABLE BRIDGE CONVEYOR RopeCon by DoppelMayr
. Ropecon by DoppelMayr, a conveyor with a special flex wall belt. . Instead of using idlers, Ropecon belt has fixed axles in belt with wheels moving on steel cables,
6 CABLE BRIDGE CONVEYOR Tacoma Narrow s Bridge
. Old Tacoma Narrows Bridge is 850m long, 12m wide, steel girder construction, commissioned in 1940. . 2nd order twisting motion at 0.2 Hz modal frequency, from wind vortex shedding.
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Limitation of Current Long Span Conveyor Solutions
. Conventional suspension bridge requires high truss towers. . Conventional suspension bridge uses arrow bridge deck that is close to the conveyor belt width. . Weak torsional stiffness from narrow deck, prone to wind- induced dynamic instability. . Ropecon from Doppelmayr is single-source supply and requires special belt, which is not compatible with conventional conveyor. . Ropecon can’t accommodate horizontal curves.
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9 CABLE BRIDGE CONVEYOR Improved Simple Suspension Bridge
. Bridge decks are directly mounted on steel cables. . Extended deck beam with stabilizing cables at the end. . No high towers required.
10 CABLE BRIDGE CONVEYOR Improved Simple Suspension Bridge
. Started in 1970s, now commonly used in hydropower dam construction to cross rivers. . Long span, quick construction and low cost. . Estimated >50 installations; longest span >400m 11 CABLE BRIDGE CONVEYOR Construction of Suspension Bridge
12 CABLE BRIDGE CONVEYOR London Millennium Bridge
. The London Millennium Bridge uses a similar but not identical design.
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14 CABLE BRIDGE CONVEYOR Cable Bridge Conveyor
. Conventional trough or pipe conveyor is supported by simple suspension bridge. . Conveyor belt line is in concave curve in the center, and convex curve near the support point. 15 CABLE BRIDGE CONVEYOR Cross Section View
Stabilizing Cable
Bridge Deck
. Typical conveyor structure can be supported by the bridge
16 CABLE BRIDGE CONVEYOR Isotropic View
. Conveyor structure is supported on deck beam. . Deck beam supported by steel cables, with stabilizing cables at the two ends. 17 CABLE BRIDGE CONVEYOR Maintenance Vehicle Option
Temporary walkway
. Using modified ATV as maintenance vehicle to replace walkway can save structural cost and increase the efficiency of maintenance. . Temporary walkway can be transported by the maintenance vehicle and
installed on CBC if needed. 18 CABLE BRIDGE CONVEYOR Pipe Conveyor Option
Temporary walkway
. Tubular pipe conveyor with frame panel arrangement, is also compatible with Cable Bridge Conveyor
19 CABLE BRIDGE CONVEYOR Side View –Near Support
Conveyor Belt line
Bridge line
. The conveyor belt line near support points is in convex curve. . The convex curve is controlled by the leg height of the conveyor structure. . The bridge cables can go over support with curve radius 35X ~ 40X cable diameter
20 CABLE BRIDGE CONVEYOR Side View –Center
Conveyor Belt line
Bridge line
. The conveyor belt line in the center is concave curve, fitting closely to the bridge line. . The arc lengths and radii of the convex and concave curve are related to the bridge line, which is also related to the span and sag. . The belt radii are designed to control belt tension and safety factor. 21 CABLE BRIDGE CONVEYOR Versatility from Long Span
. For CBC with 360m span and 40 sag ratio, transporting 2500T/H material, bridge structural weight is ~200kg/m or 134lb/ft.
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Finite Element Analysis
. Finite Element Model is used to study displacement (left figure) and stress (right figure)in the bridge structure.
23 CABLE BRIDGE CONVEYOR Modal Analysis
2nd Mode Freq=0.55
1st Mode Freq=0.37
3rd Mode 4th Mode Freq=0.57 Freq=0.70
. Vibration Analysis is done to study the modal frequency of the bridge structure. . Wind tunnel testing will be done during detail engineering stage. 24 CABLE BRIDGE CONVEYOR Summary
. Cable Bridge Conveyor is a new type of bridge based, elevated, long span conveyor. . Good solution for crossing rivers, valleys, structures. . Minimal structural footprint to protect environment . The bridge design is a mature technology with >50 installations. . Conventional trough and pipe conveyor can be used. Can accommodate horizontal curves. . Licensing is available from Cable Bridge Conveyor, LLC. US and multinational patents pending. . Overland conveyor design is available from Conveyor Dynamics, Inc.
25 Thank You
CABLE BRIDGE CONVEYOR www.cablebridgeconveyor.com [email protected]
1-866-771-2258
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