Airport Runway Geotextile Application Case
Airport Runway Geotextile Application Case
Apron Isolation Reinforcement Project
Ⅰ. Project Overview
An international airport, with Phase I construction including the new development of 3 runways and a 1.26 million m² terminal building, has a long-term plan for 6 runways and a designed annual passenger throughput of 90 million. The subbase of the airfield pavements, aprons, and service roads is subjected to repeated takeoff and landing impacts from civil aircraft (maximum load ≥ 400 kN). The original foundation consists of interbedded miscellaneous fill and silty clay, presenting three major risks:
·Differential settlement
·Capillary rise of groundwater
·Intrusion of base course aggregates into soft soil
These risks can easily trigger pavement cracking and subsidence.
Ⅱ. Geotextile Application Details
·Product Specification:
100–160 g/㎡ national standard polypropylene long-filament needle-punched geotextile (TDF® Isolation Type)
·Application Locations:
Full coverage between the base and subbase layers of runways, taxiways, and aprons
Filter wrapping at the junctions of shoulder and side slopes
Complete external wrapping around subsurface blind drains and drainage pipes
·Installation Procedure:
Subgrade acceptance passed → Geotextile laid with staggered joints (lap width ≥ 300 mm) → Joints thermally welded or stitched → Graded crushed stone base layer placed atop geotextile (thickness ≥ 200 mm) → Layer-by-layer compaction (compaction degree ≥ 96%)
·Quantity Used: Total cumulative usage across the site: 2 million m²
Ⅲ. Core Functions of Geotextile
·Separation: Prevents the upper layer of graded crushed stone aggregate from penetrating into the underlying soft soil, avoids intermixing between the base and subbase layers, and maintains the designed thickness of the structural layers.
·Filtration and Drainage: Rapidly drains trapped water from the base layer, reduces pore water pressure, blocks capillary rise of groundwater, and prevents softening or pumping (mud ejection) of the base.
·Stress Distribution: Uniformly spreads aircraft wheel loads, reduces additional stress on the subgrade, and helps control differential settlement.
·Reinforcement and Stabilization: Enhances the overall stiffness of the base layer, suppresses the propagation of reflective cracks, and extends the service life of the pavement.
Ⅳ. Implementation Results
·Pavement Settlement: Post-construction settlement ≤ 20 mm, significantly lower than the design limit of 50 mm; no differential or uneven subsidence observed.
·Drainage Performance: No surface ponding or pumping during the rainy season; subsurface blind drains remain unobstructed and free of silt/sand accumulation.
·Structural Integrity: Since commissioning, the pavement shows no visible cracks or aggregate loss, and the maintenance cycle has been extended by a factor of 2.
·Economic Benefits: Approximately 15% reduction in crushed stone fill usage, 35% decrease in long-term maintenance costs, and an overall construction schedule shortened by 10%.
