Photo Credit © Amar Ramesh

Services provided for the general contractor

  • Mentor existing survey teams, offering strategic guidance, methodology development, implementation, refinement and task specific training (if required)
  • Perform independent survey audits for existing methodology, control networks and permanent survey records archive
  • Develop QA systems for all geometry control related data, including instrument calibration
  • Determine all T0 pre-camber, over-height, over-length co-ordinate requirements for setting out
  • Design Microsoft Excel spreadsheets to post-process set-out and as built survey data
  • Liaise with the finite element modeling engineer, to select suitable construction stages for as-set / as-built cross-check survey measurement comparisons
  • Determine environmental influences for structural deformation, and derive the true construction errors, from observed deflections
  • Assist structural steel fabricators with welding method optimization, to increase productivity, maintain geometry control specifications and minimize heat induced distortions / locked in stresses
  • Oversee geometry control QA issues pertaining to structural steel fabrication, trial assembly & erection
  • Oversee geometry control issues pertaining to pre-cast concrete deck segment casting
  • Make periodic site visits to observe existing survey measurement procedures



Photo Credit © Hufton + Crow

Services provided for the fabrication sub-contractor

  • Review all methodology submission requirements from the general contractor, pertaining to field procedures for surveying, geometry control, QC inspection, QA documentation
  • Assist with methodology preparation / revisions – during the procedural approval process
  • Perform risk-assessment on existing methodology for fabrication / trial assembly, including weld heat induced deformation control and temporary support subsidence.
  • Offer suggestions for method improvement – to decrease potential errors, minimize costs and optimize fabrication schedule
  • Establish true ‘technology transfer’, for industry standard surveying techniques, including customized software for post-processing of raw field data, in-house periodic equipment calibration programs and optimized survey targeting devices

Services provided for the supervision engineer

  • Review all methodology submissions from the general contractor, pertaining to field procedures for surveying, geometry control, QA documentation, fabrication
  • Review all set out survey data, prior to concrete placement or steel fabrication fit-up
  • Review all as-built survey data, including deflections and environmental data, to determine construction errors and corrective actions
  • Review periodic settlement / elastic shortening survey data of pile caps
  • Make periodic site visits to observe existing survey measurement practices and procedures
  • Manage the QA systems pertaining to structural steel fabrication and trial assembly survey data
  • Manage the QA systems pertaining to pre-cast concrete deck segment casting



Photo Credit © Ted(bobosh_t) CC License

Services provided for the designer

  • Establish realistic survey measurement tolerances for all components of the cable stayed pile caps, pylons, deck assemblies and cable anchorages. Based on estimates of survey measurement accuracy and standard deviations, derive fabrication tolerances for the permanent works structural steel and as-set tolerances for concrete shutter positional accuracy
  • Assist with preparation of the survey specifications for the tender document bid package
  • Help establish accuracy requirements for trial assembly of the deck / pylon components and identification / control of all environmental influences during as-set surveys
  • Establish minimum requirement guidelines for the Contractor’s proposed geometrical control methodology, construction and survey measurement error identification and mitigation, including definitions of T0, T1 and T (reference) co-ordinate systems
  • Review various cable stayed span design proposals for constructability, analyzing schedule time against costs and the range of achievable accuracies against relative survey equipment capital expense.
  • Work with the structural engineer in charge of the finite element analysis model, to match suitable construction stages against the most advantageous opportunities for accurate confirmation surveys, free of environmental factors
  • Work with the erection engineer to devise (at least) one possible surveying / geometry control methodology, to demonstrate to the client that the project is buildable, to the accuracy tolerances specified in the tender documents.



Photo Credit © Amar Ramesh

Services provided for the owner/concessionaire

  • Perform value engineering on proposed designs and construction methodologies, highlighting the issues pertaining to construction, surveying and geometry control, with respect to cost, schedule, achievable levels of accuracy and risk.
  • Work with the designer to refine elements of the design, to reach a buildable structure, with cost savings shared among all parties
  • Work with the general contractor, to improve erection methodology and reduce cycle times, thus reducing costs.
  • Ensure that the supervision engineer and the general contractor are adhering to the QA documentation procedures for geometry control related data
  • Analyze the survey / geometry control data submitted to the supervision engineer – as part of the QA review procedure.
  • Make random, unscheduled site visits, to ensure approved survey methodology is being followed
  • Be available on site (rapid response) to troubleshoot any unforeseen problems that arise, with respect to survey methodology, geometry control or unexpected structural behavior
  • Assist with implementation of the structural health monitoring system, with regards to GPS receivers, accelerometers, anemometers and data collection interface software
  • Design the periodic survey measurement monitoring procedures for the duration of the concession period