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Client: Panama Canal Authority

Location: Balboa, Republica de Panama

 
During 2013 Arc Surveying & Mapping, Inc (Arc) was contracted by the Panama Canal Authority (ACP) Locks Division to perform surveys required to evaluate structural damage caused to the north guidewall support piling by waterborne termites.  A portion of the piling, driven into the subsurface over 100 years previous, became exposed to open water as sediment under the structure eroded exposing piling to termites.  Termites ate completely through many piles and severely destroyed the integrity of others, causing the supported concrete deck to crack as is subsided.  ACP divers identified some of the damage by feeling the pile and drawing their findings as best they could.  The murky waters of the Panama Canal obscured vision and constant ship traffic transiting the locks limited diver accessibility.  Arc and ACP developed a plan that would provide canal engineers with sufficient detail to understand the extent of damage and generate construction repair drawings and specifications:

  • Establish/verify horizontal and vertical control in the appropriate datum

  • Perform a terrestrial laser scan of the above water surface of the guidewall

  • Perform a high resolution multibeam swatch survey around the guidewall

  • Generate a 3D computer model of the structure from 100 year old drawings

  • Perform a Blueview sonal scan under the guidewall locating damaged piling

  • Combine all survey data into an interactive 3D MicroStation model

  • Generate maps illustrating erosion areas

  • Provide a cubic meter quantity of fill required to fill the voids

Terrestrial laser scanning of the above water portion of the lock wall was accomplished utilizing a Riegl VZ400 capable of collecting 122,000 georeferenced measurements per second with 5mm accuracy/3mm repeatability at a range of 600m (1,968 ft.).  The Bathymetric survey of the underwater portion of the northern guidewall was performed by ACP utilizing a Reson 7125 SeaBat multibeam swath system.  A Blueview Sonar Scanner MB1350 with a range of 90 ft. operating at 1.35 MHz with 256 beams and a time resolution of 0.015m was lowered from the guidewall and placed under the guidewall by divers to locate the deteriorated wooden pile.