Jeffrey L. RapolJeffrey L. Rapol, Civil EngineerFederal Aviation Administration
Airport Engineering Division, AAS-100800 Independence Ave, SW Room 621V
Washington, DC 20591Phone: (202) 267-7474; Fax: (202) 267-3688
Qiang WangQiang Wang, Ph.D.SRA International Inc.
1201 New Road, Suite #242Linwood, NJ 08221, U.S.A.
Phone: (609) 601-6800; FAX (609) [email protected]
Outline of PresentationOutline of Presentation
Introduction to Runway GroovesIntroduction to Runway Grooves
Groove Measurement and Identification SystemGroove Measurement and Identification System
Groove Identification Program – Groove Identification Program – ProGrooveProGroove
--- Procedures--- Procedures
--- Techniques--- Techniques
--- Functions--- Functions
Verification of Verification of ProGrooveProGroove ProgramProgram
When aircraft tires or highway vehicle tires roll over water covered or
flooded pavements, water may penetrate between the tire and the
pavement. This penetration results in the formation of water pressure which
raises a portion of the tire off the pavement.
Introduction to Runway GroovesIntroduction to Runway Grooves
This pressure increases as the speed of the vehicle
increases, supporting more and more of the tire,
until, at a critical speed termed the hydroplaning
speed, the tire is supported only by the water and
loses all contact with the pavement.
Tire Hydroplaning
Cutting or forming grooves in existing or new pavement, which would allow rain water to escape from beneath tires of landing aircraft, is a proven and effective technique for providing skid-resistance and prevention of hydroplaning during wet weather.
The FAA standard groove configuration is 1/4 inch (6 mm) in depth by 1/4 inch
(6 mm) in width by 1 1/2 inch (38 mm) center to center spacing.--- FAA: AC 150/5320-12C
''4
1 ''
4
11
''4
1 ''
2
11
Introduction to Runway GroovesIntroduction to Runway Grooves
The airport operator should periodically measure the depth and width of a runway's grooves to check for wear and damage.
--- FAA: AC 150/5320-12C Groove Tolerance.
Depth and Width: At least 90% grooves ≥ 3/16 inch;
At least 60% grooves ≥ 1/4 inch;Not more than 10% grooves ≥ 5/16 inch.
Center-To -Center Spacing:
1-3/8 inches ≤ Spacing ≤ 1-1/2 inches.
--- FAA: AC 150/5370-10E
Introduction to Runway GroovesIntroduction to Runway Grooves
''
4
1
''4
1
''
2
11
Using a laser displacement sensor, the rapid measurement of surface elevation profiles can be achieved to sufficient accuracy and at fine enough sample spacing to define the characteristics of transverse grooves on airport runways.
Groove Measurement andGroove Measurement and Identification SystemIdentification System
Groove IdentificationProGroove
Signal Acquisition Unit
Acceleration Sensor
Displacement Sensor
Distance Sensor
Grooves on Airport Runway
The computer program, ProGroove, was developed which automatically identifies grooves in an elevation profile and computes the dimensions of the grooves.
Groove Identification ProgramGroove Identification Program
The profile data is first high-pass filtered at 0.07 cycle/ft to remove the roughness components in the profile.
The high-pass filtered profile data is followed by low-pass filtering at 3.3 cycle/ft to provide a datum against which groove-like disturbances can be compared.
The low-pass filtered datum provides a moving average of the profile which lies between the top and the bottom of the grooves for comparison.
Groove-like disturbances of joints in concrete pavements are found and removed from the counted grooves.
The potential groove depth and width are double checked for assuring the groove depth and width within the defined limits.
The results of the groove depth and width are statistically analyzed, displayed, and printed out to the files.
Groove Identification ProcedureGroove Identification Procedure
1.
2.
3.
4.
5.
6.
To find the start point and end point of each groove is performed on checking
the difference between the sample value and the low-pass criteria.
-4.00E-01
-3.00E-01
-2.00E-01
-1.00E-01
0.00E+00
1.00E-01
2.00E-01
9.2 9.21 9.22 9.23 9.24 9.25
Selcom
SelAve
Comparing with Moving Average of the ProfileComparing with Moving Average of the Profile
Find Start Point and End Point of each GrooveFind Start Point and End Point of each Groove
Yes
Yes
Yes
No
Give TD = threshold of depth, TW= threshold of width TS = threshold of, space, TJ = threshold of joint Set initial number of grooves, I = 1 Set initial number of points in the groove, J = 0 For each sample point, K No. Go to Subroutine of Calculation K ≤ K max of groove depth Calculate the minimum number of points in each groove, N(v) D = Sample data - Low pass filter data No D > TD Yes No No J < N(v) J < N(v) Yes J = 0 J = 0 Set the start point of the groove, Nlow(I) = K Count the number of points in the groove, J = J + 1 Set the end point of the groove, Nup(I) = K Increase the number of grooves, I = I +1
1. The start point is localized at the difference between the sample data and filter data is greater than the given depth threshold.
2. Calculate the minimum number of points in each groove, N(v), which depends on the vehicle speed.
3. If the number of satisfied difference between the sample and filter data is greater than the N(v), the potential groove is identified.
4. Then, the end point is found as the difference between the sample data and filter data less than the depth threshold.
Critical Frequency Depends on the Vehicle SpeedCritical Frequency Depends on the Vehicle Speed
The vehicle speed usually changes at the start and end periods of test. If using low-pass filter to identify the grooves , the critical frequency can be adjusted to the vehicle speed on the specific time interval.
-0.35
-0.3
-0.25
-0.2
-0.15
-0.1
-0.05
0
0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Time, s
Se
lco
m V
alu
e, i
n.
Selcom
Low Pass: 1 HzLow Pass: 10 Hz
Low Pass: 50 Hz
The profile data is first high-pass filtered at 0.07 cycle/ft to remove the roughness components in the profile.
The high-pass filtered profile data is followed by low-pass filtering at 3.3 cycle/ft to provide a datum against which groove-like disturbances can be compared.
The low-pass filtered datum provides a moving average of the profile which lies between the top and the bottom of the grooves for comparison.
Groove-like disturbances of joints in concrete pavements are found and removed from the counted grooves.
The potential groove depth and width are double checked for assuring the groove depth and width within the defined limits.
The results of the groove depth and width are statistically analyzed, displayed, and printed out to the files.
Groove Identification ProcedureGroove Identification Procedure
1.
2.
3.
4.
5.
6.
Remove the Joints from the Test DataRemove the Joints from the Test Data
To determine the joints from a series of grooves is based on the two normally
spaced grooves. It is obvious that the joint space is much greater than the normal
groove space. Distance Between Two Grooves
0 2 4 6 8 10 12 14 16 18
0.47
3.99
5.35
6.66
8.16
9.67
11.34
13.13
14.55
16.00
17.35
18.72
20.31
21.83
23.52
Tim
e,
s.
Groove Distance, in.
The profile data is first high-pass filtered at 0.07 cycle/ft to remove the roughness components in the profile.
The high-pass filtered profile data is followed by low-pass filtering at 3.3 cycle/ft to provide a datum against which groove-like disturbances can be compared.
The low-pass filtered datum provides a moving average of the profile which lies between the top and the bottom of the grooves for comparison.
Groove-like disturbances of joints in concrete pavements are found and removed from the counted grooves.
The potential groove depth and width are double checked for assuring the groove depth and width within the defined limits.
The results of the groove depth and width are statistically analyzed, displayed, and printed out to the files.
Groove Identification ProcedureGroove Identification Procedure
1.
2.
3.
4.
5.
6.
Remove the Joints from the Test DataRemove the Joints from the Test Data
The potential groove depth and width are double checked for assuring thegroove depth and width within a reasonable range.
-1.4
-1.2
-1
-0.8
-0.6
-0.4
-0.2
0
0.2
23.3 23.32 23.34 23.36 23.38 23.4 23.42 23.44 23.46 23.48 23.5
Time, s
Se
lco
m, i
n.
Checked by Depth
Checked by Width
The profile data is first high-pass filtered at 0.07 cycle/ft to remove the roughness components in the profile.
The high-pass filtered profile data is followed by low-pass filtering at 3.3 cycle/ft to provide a datum against which groove-like disturbances can be compared.
The low-pass filtered datum provides a moving average of the profile which lies between the top and the bottom of the grooves for comparison.
Groove-like disturbances of joints in concrete pavements are found and removed from the counted grooves.
The potential groove depth and width are double checked for assuring the groove depth and width within the defined limits.
The results of the groove depth and width are statistically analyzed, displayed, and printed out to the files.
Groove Identification ProcedureGroove Identification Procedure
1.
2.
3.
4.
5.
6.
Depth, Width and Standard Deviations of the GroovesDepth, Width and Standard Deviations of the Grooves
Storage Information of Groove Identification to a FileStorage Information of Groove Identification to a File
Verification to Manual MeasurementsVerification to Manual Measurements
The groove data were tested at the Atlantic City Airport on October 22, 2008. Instrumental test and manual measurement were recorded for ProGroove analysis.
Verification to Manual MeasurementsVerification to Manual Measurements
ProGroove and Manual Measurement at ACY in Slab 14
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
1 21 41 61 81 101 121 141 161 181
Groove Number
Gro
ove
Dep
th, i
n
Manual
ProGroove
Standard Deviation = 0.02044
Verification to Manual MeasurementsVerification to Manual Measurements
ProGroove and Manual Measurement at ACY in Slab 14
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
1 21 41 61 81 101 121 141 161 181
Groove Number
Gro
ove
Dep
th, i
n
Manual
ProGroove
Standard Deviation = 0.02044
1
2
3
t1 = 14.40988 st2 = 14.41913 st3 = 14.42788 s
Select three typical points for comparisonSelect three typical points for comparison
Verification to Manual MeasurementsVerification to Manual Measurements
ProGroove – Manual = Error
1 0.270 – 0.166 = 0.104 large
2 0.216 – 0.203 = 0.013 small
3 0.192 – 0.188 = 0.004 very small
Error Reason: Manual measurement can not reach the tip of narrow groove.
0.270
0.166
t 1 = 14. 4099
12 3
0.203
0.216
0.1920.188
t 2 = 14. 4191
t 3 = 14. 4279
ConclusionsConclusions
ProGroove software can automatically identify the airport runway
grooves by signal processing of the instrumental test data.
ProGroove software provides the groove number, location, depth and
width, as well as a series of statistical results for groove quality analysis.
The comparison of analyzed data from ProGroove software with manual
measurement shows good coincidence.
The results of groove analysis can be used for verifying the initial
construction of the groove quality or supplying the recommendations to
the airport’s maintenance program.
AcknowledgmentsAcknowledgments
• NAPTF, FAA
– Satish Agrawal
– Jeffrey Gagnon
– Gordon Hayhoe
– David R. Brill
– Robert Flynn
– Navneet Garg
– Albert Larkin
– Frank Pecht
• SRA
– Chuck Teubert
– Jerry Connelly
– Edward Guo
– Hector Daiutolo
– Izydor Kawa
– Injun Song
– Harkanwal Brar
– James Zargan