Subgrade stress ratios as airfield pavement rutting performance indicators

2007 ◽  
Vol 34 (2) ◽  
pp. 189-198
Author(s):  
Kasthurirangan Gopalakrishnan ◽  
Marshall R Thompson
Keyword(s):  
Transfer Functions ◽  
Flexible Pavements ◽  
Federal Aviation Administration ◽  
Flexible Pavement ◽  
Test Facility ◽  
Airport Pavement ◽  
Study Results ◽  
The Us ◽  
Stress Ratios ◽  
New Generation

Rutting is a major distress in airport flexible pavements. Subgrade vertical strain criteria are used in many airport flexible pavement design procedures to consider the development of rutting. Several research studies have identified the limitations associated with these criteria. Design criteria based on subgrade stress ratios (SSRs) are being considered for evaluating subgrade rutting in airport flexible pavements. In this paper, the SSRs based on measured vertical subgrade stresses are related to surface rutting in flexible pavements subjected to repeated trafficking of Boeing 777 and 747 simulated test gears at the US Federal Aviation Administration (FAA) National Airport Pavement Test Facility (NAPTF). The results indicated overstressing of the subgrade in two test sections, and this was confirmed by trench study results. A good correlation was obtained between the SSRs and the surface rut depths, supporting the validity of developing SSR-based rutting transfer functions for airport flexible pavements serving the next generation of aircraft.Key words: rutting, subgrade stress ratio (SSR), National Airport Pavement Test Facility (NAPTF), pressure cell (PC), new generation aircraft, airport flexible pavement.

scholarly journals PREDICTING CAPACITIES OF RUNWAYS SERVING NEW LARGE AIRCRAFT

Transport ◽  
2008 ◽  
Vol 23 (1) ◽  
pp. 44-50 ◽  
Author(s):  
Kasthurirangan Gopalakrishnan
Keyword(s):  
Functional Performance ◽  
Flexible Pavements ◽  
Evaluation Methodology ◽  
Test Facility ◽  
Simplified Approach ◽  
Pavement Surface ◽  
Airport Pavement ◽  
Surface Deflections ◽  
Non Destructive ◽  
Large Aircraft

This paper presents a simplified approach for predicting the allowable load repetitions of New Large Aircraft (NLA) loading for airfield runways based on Non‐Destructive Test (NDT) data. Full‐scale traffic test results from the Federal Aviation Administration's National Airport Pavement Test Facility (NAPTF) were used to develop the NDT‐based evaluation methodology. Four flexible test pavement sections with variable (unbound layer) thicknesses were trafficked using six‐wheel and four‐wheel NLA test gears until the test pavements were deemed failed. Non‐destructive tests using a Heavy Weight Deflectometer (HWD) were conducted prior to the initiation of traffic testing to measure the pavement surface deflections. In the past, pavement surface deflections have been successfully used as an indicator of airport pavement life. In this study, the HWD surface deflections and the derived Deflection Basin Parameters (DBPs) were related to functional performance of NAPTF flexible pavements through simple regression analysis. The results demonstrated the usefulness of NDT data for predicting the performance of airport flexible pavements serving the next generation of aircrafts.

Iterative Framework for Performance and Environmental Impacts of Airfields

2019 ◽  
Vol 2673 (9) ◽  
pp. 179-187
Author(s):  
Izak M. Said ◽  
Imad L. Al-Qadi
Keyword(s):  
Life Cycle ◽  
Energy Demand ◽  
Federal Aviation Administration ◽  
Test Facility ◽  
Traffic Loading ◽  
Secondary Sources ◽  
Field Instrumentation ◽  
Airport Pavement ◽  
Performance Check ◽  
Layered Design

The main goal of a durable and sustainable airfield is to withstand repeated aircraft traffic loading while minimizing the environmental impact. The objective of this study is to develop a design-life cycle assessment (LCA) framework considering a balanced evaluation of structural adequacy, minimizing emission, and optimizing total energy demand. To achieve this objective, three steps are introduced: an evaluation of the structural adequacy of the design using the Federal Aviation Administration (FAA) pavement design software FAA rigid and flexible iterative elastic layered design; a preliminary performance check using field instrumentation responses; and a LCA of airfield sections using both deterministic and probabilistic approaches. In addition to presenting the design-LCA methodology, this paper offers a comparative evaluation that covers two perpetual designs (LFP1-N and LFP4-N) and one conventional section (LFC5-N). These pavement sections were built and tested at the National Airport Pavement Test Facility as part of construction cycle 7, funded by the FAA. Responses collected from instrumentation were used to compute field-based coverages to failure. Moreover, life cycle inventories from secondary sources were used to quantify the greenhouse gas emissions and energy demand associated with the construction of these sections. Results show inconsistencies between the field-predicted and theoretically predicted performance. This suggests the need for the additional calibration of the currently used performance models. Moreover, this study shows that under a specific asphalt concrete (AC) thickness limit, conventional AC may be more eco-friendly than a perpetual design.

Airport Pavement Groove Identification and Analysis at NAPTF

2013 ◽  
Vol 723 ◽  
pp. 1003-1010 ◽  
Author(s):  
Qiang Wang ◽  
Josh Davis
Keyword(s):  
High Speed ◽  
Federal Aviation Administration ◽  
Automatic Device ◽  
Test Facility ◽  
Laser Sensor ◽  
Rigid Pavement ◽  
Airport Pavement ◽  
Grooved Surface ◽  
Groove Configurations ◽  
Transverse Grooves

Transverse grooves in an airport pavement allow water to be ejected from beneath the tires of an aircraft moving at high speed. It has been found that the grooves can efficiently reduce the hydroplaning potential of a pavement during wet weather. The Federal Aviation Administration (FAA) maintains a standard specification for groove configuration immediately after construction and during service. The National Airport Pavement Test Facility (NAPTF) performed a long period of real scale tests to investigate the performance of the current FAA standard square grooves and proposed trapezoidal grooves. This paper includes the comparison of trapezoidal and rectangular grooves under aircraft tire loading with service life. These two groove patterns were constructed on the flexible and rigid pavement respectively. In the automatic device measurement, a laser sensor from a truss profiler constantly detected the distance between the grooved surface and an initial standard line as the aircraft tires repeatedly passed through the grooved areas. An automatic groove identification program was also developed to evaluate the groove configurations. Our test results demonstrate that the trapezoidal grooves maintain a longer life shape configuration than rectangular grooves, especially for asphalt pavements.

Airfield Pavement Damage Evaluation Due to New-Generation Aircraft Wheel Loading and Wander Patterns

2018 ◽  
Vol 2672 (29) ◽  
pp. 82-92 ◽  
Author(s):  
Priyanka Sarker ◽  
Erol Tutumluer
Keyword(s):  
Residual Deformation ◽  
Federal Aviation Administration ◽  
Test Facility ◽  
Initial Attempt ◽  
Stress History ◽  
History Effects ◽  
Aircraft Landing ◽  
Airport Pavement ◽  
Wheel Loading ◽  
Pavement Damage

This paper presents a stress-history-based approach to predict the deformation basins of airport pavements subjected to heavy aircraft loading applied in sequential wanders. Multi-depth deflectometer data from full-scale aircraft landing gear tests conducted at the National Airport Pavement Test Facility built by the Federal Aviation Administration are used to create individual pass residual deformation transverse profiles. The computed residual deformation profiles are further corrected for stress-history effects to predict rut in the selected test sections. The developed model focuses on using the previous load location and stress history of the soil element to develop the deformations in that element. Despite the unavailability of the surface transverse profile data measured in the field at different passes, the initial attempt of the model can closely predict the deformation profile similar to width and shape expected in the field. And after the stress-history effects are accounted for, the initially calculated rut depth decreases significantly to match the final contour basin of the test sections extracted from the post traffic trenching. The advantage of using the stress-history-effects-based rut prediction tool is that it can allow any combination of wander positions and sequences of load applications to be accounted for their effects on the final surface rut development.

Development of Domain Analysis to Predict Multi-Axial Flexible Airfield Pavement Responses Due to Gear and Environmental Loadings

2018 ◽  
Vol 2672 (40) ◽  
pp. 326-335 ◽  
Author(s):  
Angeli Gamez ◽  
Jaime A. Hernandez ◽  
Imad L. Al-Qadi
Keyword(s):  
Transfer Functions ◽  
Three Dimensional ◽  
Domain Analysis ◽  
Test Facility ◽  
Response Analysis ◽  
Near Surface ◽  
Surface Cracking ◽  
Cracking Potential ◽  
Airport Pavement ◽  
Truck Tire

Flexible pavement design procedures use maximum mechanistic strains to predict service life via empirical transfer functions. The conventional method of using predefined point locations for potential damage may not accurately represent realistic pavement scenarios. For instance, flexible airfield pavement analysis mainly considers the critical strain at the bottom of the asphalt concrete (AC), which may not characterize near-surface cracking potential. In lieu of point strains, domain analysis, a new method, accounts for the multi-axial behavior of pavements, as inherently excited by three-dimensional (3-D) and nonuniform aircraft tire–pavement contact stresses. Initially applied on highway pavements considering truck tire loading, this approach is an initial breakthrough for implementing domain analysis on flexible airfield pavements; in this study, A-380 and F-16 landing gear tire loads were considered. As anticipated, speed and temperature had significant influence on cumulative domain stress and strain ratios. The decrease in speed and increase in temperature not only increased the cumulative ratios up to 1.81, but nonlinearity of the problem became more prevalent at worst loading conditions (8 kph and 45°C). Minimal difference in ratios for F-16 cases suggests that the National Airport Pavement Test Facility pavement structure became less sensitive to conditions under low loads. Point response analysis revealed that critical strains were not significantly influenced by the tire-inflation pressure, for example, tensile strain at the bottom of the AC only increased up to 13.6% (considering 8 kph speed), whereas domain analysis quantified the increase with respect to 3-D stress or strain states.

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