Bridge Weighing

 

Port Mann Bridge – British Columbia, Canada

Using a custom designed system consisting of 10 x 900 ton hydraulic cylinders and 10 x 900 ton resistance loadcells, we were able to accurately weigh the individual bridge sections

Precision Weighing

With over 50 years experience in the industry we have the capability to weigh any structure whether it be a bridge, building or stadium, accurately and precisely.

Computer controlled lifting and lowering system

  • Personal computer based control unit with user-friendly Windows interface
  • Digital control of the lifting process accurate to + – .04” [1mm] between leading and lagging lifting points
  • Multiple lift point capability, from 2 to 24 points
  • Data recording, graphic presentations and print-out capability
  • Automatic stop at pre-set stroke or load limit

Setting new standards in precision and control

  • Accuracy 
    – Digital control of the lifting process accurate to + – .04” [1mm] between lifting points 
    – Real time, on screen monitoring provides complete lift status 
  • Safety 
    – Digital control programmed for “Fail-Safe” operation 
    – Actual load movement is measured 
    – Pilot-operated check valves automatically hold cylinder pressure in the event of hose failure 
  • Serviceability 
    – Worldwide network of Enerpac Authorized Service Centers 
    – Uses easy-to-service, standard Enerpac components 
  • Ease of Operation 
    – One person operation 
    – PC-based controller runs in Windows environment 
    – Point-and-click mouse control 
    – Multi-lingual data screens available 
    – Standard Enerpac 10,000 psi single- and double-acting cylinders

Calibrated Flat Jacks & Weighing

A flat jack which has been pre-opened, fitted with a pressure gauge or transducer, sealed and then calibrated in a press can be used as a robust, accurate load cell. This load cell can be placed in tandem with a standard flat jack of the same size.

The twin jacks are then installed beneath a structure at weighing positions. The weight of the structure taken by inflation of the standard flat jack registers a pressure in the calibrated flat jack which, by reference to its calibration graph, provides an accurate weight.

Using this principle, offshore structures ranging from modules of several hundred tonnes to complete integrated decks of over 30,000 tonnes to an accuracy of +/- 1%. Where necessary for lighter structures, an arrangement is available with greater accuracy.

The twin jacks are then installed beneath a structure at weighing positions. The weight of the structure taken by inflation of the standard flat jack registers a pressure in the calibrated flat jack which, by reference to its calibration graph, provides an accurate weight.

Using this principle, offshore structures ranging from modules of several hundred tonnes to complete integrated decks of over 30,000 tonnes to an accuracy of +/- 1%. Where necessary for lighter structures, an arrangement is available with greater accuracy.

– Known Forces
– Precise Control
– Low Height For Limited Access Situations
– Low Bearing Stresses
– Out Of Parallel Tolerance  
– Between Jacking Surfaces
– Temporary, Removable Jacks
– Permanent, Sacrificial Jacks
– Structural Lifting
– Underpinning
– Control Of Thrust Forces
– Maintenance Of ConstantThrust 
– Adjustment Of Support  Reactions
– Pretressing
– Structural Pre-Loading
– Loading Of Seismic Isolators
– Arch De-Centering
– Control Of Settlement
– Measurement Of Forces
– Weighing Of Offshore Structures
– Permanent Shimming

Freyssi Flat Jack Chart

Using a combination of 10 x 800 Ton Hydraulic Cylinders & 10 x 800 Ton Loadcells the new bridge sections were accurately weighed to within 2% of theoretical loads. After the weight of each section was verified the bridge sections were then loaded into place.

WB Equipment Corp.