What is the construction sequence at the civil interface?
The order in which survey, ducts, bases, pavement and AGL fit-out are built, set by one rule: finish and check what will be covered before the next layer goes over it.
The construction sequence is the order in which the civil and AGL works are built so that each stage is finished and checked before it is covered. The works go in from the ground up: survey and set-out, excavation, ducts, pits and handholes, bases and foundations, pavement, then the AGL fit-out and tests, and last the close-out with as-built records and the defects list.
The order is set by what covers what. Ducts, pits and bases end up under backfill, concrete or asphalt, so a hold point stops the work for a joint check, normally before backfill and before paving, and again at handover. A fault found afterwards means breaking out finished work. The layout is also frozen before bases are set, because a position or direction changed after casting usually means breaking it out. Excavation and paving happen under the airport’s permit-to-work, with existing cables located and protected and any AGL circuit isolated before work near its cables.
The order of the stages and why: what must be finished and checked before it is covered.
Who owns each item, and how scope, drawings and tolerances are agreed between the two teams.
Frequently Asked Questions
Q1What is the construction sequence in the civil interface?
It is the order in which the civil and AGL works are built: survey and set-out, excavation, ducts and pits, bases and foundations, pavement, AGL fit-out and tests, then close-out. The order follows one rule: what will be covered is finished and checked before the next layer goes over it.
Q2Why does the order matter so much?
Ducts, pits, bases and foundations end up buried under backfill, concrete or asphalt. If a duct is out of line or a base is at the wrong level and is only found afterwards, the fix means breaking out finished work, which costs time, money and airfield possessions.
Q3What are hold points and where do they fall?
A hold point is a stop where the work is checked and signed off before it is covered. Typical ones are ducts and pits before backfill, bases and foundations before paving, and the tested installation before handover. The contract and the quality plan set the exact list.
Q4Why are ducts, pits and bases built before the pavement covers them?
They sit below or within the pavement layers, so they must be in place and checked before those layers are placed. Whether a can is set in the final course or earlier with temporary protection depends on the pavement design and the method statement, so follow the contract documents.
Q5Why do fixtures and tests come last?
Fitting fixtures after the pavement is finished keeps them clear of paving plant and damage, and lets alignment and elevation be set against the final surface. Circuit tests then prove the installation as it will be handed over.
Q6What happens if the design changes after a base is set?
A change after a base or foundation is cast usually means breaking it out. The layout is frozen before bases are set, and any later change is agreed between the civil and AGL leads and recorded before work continues.
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