Services · 03
As-built surveys & construction site base maps
Engineering-geodetic measurement and mapping across the design, construction and operation of buildings, utilities, roads and railways.
What this is
Geodetic work on a construction project runs in three stages: producing the base mapping the design is drawn on, setting that design out on the ground and checking it as the structure goes up, and then verifying geometry and deformation once it is in service. They are not separable jobs — the accuracy achievable in each stage is set by the one before it.
What you end up with
As-built drawings, measurement acts and reports in the form an inspecting authority will accept — with every departure between design and built work documented rather than discovered later.
- 01Topographic and site base maps
- 02Control point design and installation
- 03Setting-out to design geometry
- 04As-built survey and verification measurement
- 05Deformation and settlement monitoring
- 06Measurement acts, reports and coordinate catalogues
In detail
One — at design stage
The object is positioned on the ground, the alignment is investigated, and the geodetic and topographic material behind the design is produced. Existing large-scale mapping is drawn from the state geodetic and cartographic fund and checked against the ground — or, where the site cannot be reached, against aerial and satellite imagery of the period — and a judgement is given on whether it must be renewed. Renewal is carried out in the WGS-84 coordinate system and UTM projection approved by Government Resolution 29 of 2009, to the content, accuracy and scale required by sections 8–19 of part 2 of BNbD 11-07-04.
Two — during construction
Control points are planned against the general layout drawing under clauses 3.3 and 3.6 of BNbD 11-08-06. Permissible error and required accuracy are written into the brief before work starts, not settled afterwards.
- Establishing and protecting control points, with check measurement in position and height
- Transferring axes to the ground and marking longitudinal sections, cross-sections and curve elements
- As-built measurement, processing and certification at each construction stage
- Client, designer and contractor verification measurement, with the acts drawn up
Three — in service
Marks and benchmarks are set into walls, columns and foundations so that position and height can be re-measured on the same references. Verification is repeated on a defined cycle, and the action to be taken if error exceeds tolerance is agreed in advance rather than improvised when it happens.
One legal note worth knowing
Under article 9.1 of the Law on Geodesy and Cartography, work funded from the state or local budget, or from a state body’s project funds, must have its reports, coordinate schedules, drawings and digital data transferred to the national fund free of charge. Worth budgeting for as a deliverable rather than meeting it as a surprise at handover.
Standards and norms
Work is delivered against Mongolian statute and construction norms.
- —Law on Geodesy and Cartography
- —Law on Cadastral Surveying and the Land Cadastre
- —Government Resolution 25 of 2009
- БНбД 11-07-04General basis for engineering survey of structures — part 2, engineering-geodetic work
- БД 11-106-08Topographic base mapping at 1:500–1:5000
- БНбД 11-08-06Geodetic work in construction
- БД 11-104-06Establishing permanent geodetic points and marks
- БД 11-105-06Utility network surveying
- БД 11-115-16Geodetic work for water and heat supply, sewerage and flood structures
- БД 11-118-17Deformation measurement of tall structures and geodetic work for installing industrial plant
- БНбД 32-07-10Railway and road tunnel structures — chapter 4, geodetic and mine-surveying work
- БД 81-103-13Reference pricing for geodetic and cartographic work
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