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Publication Number: FHWA-RD-03-093
Date: August 2006

Study of Long-Term Pavement Performance (LTPP): Pavement Deflections

Appendix A. Various Feedback Reports Submitted to FHWA

On the following pages, Feedback Reports RNS–2M, RNS–3, RNS–4M, RNS–5, RNS–6, and RNS–7 are reproduced (without their attachments).

TO: Long-Term Pavement Performance Program
HRDI–13

6300 Georgetown Pike
McLean, VA 22101–2296
Facsimile: (202) 493–3161
Email: LTPPINFO@fhwa.dot.gov
LTPP

 

LTPP Data Analysis/Operations
Feedback Report
Report No.: RNS–2M
Date: 28 December 2000
Submitted by: R. N. Stubstad, E. Lukanen and L. Clevenson
Subject: LTPP FWD Load-Deflection Configuration Data in the Database
Situation:
For several distinct time periods for certain FHWA-owned and non-owned FWDs, several of these units were used with the deflection sensors placed incorrectly along the raise-lower bar. These non-protocol sensor spacings are still recorded as being in the protocol positions in the level E database. The measured deflections appear to be correct; however large errors in (for example) backcalculation will occur if the actual sensor positions are not recorded and used together with the measured deflections. The attached letter outlines the correct positions of the sensors in a list of instances were there was incontrovertible evidence to support the newly reported sensor positions. This new list is a slight modification of the RNS–2 Feedback Report submitted during 1999. This Feedback Report supercedes RNS–2, called RNS–2M (modified).
Recommended Action:
Revise the sensor configuration table in the database to reflect the actual, not protocol, sensor positions, as outlined in the attached letter. (NOTE: The sensor position table is not easily accessible when the FWD load-deflection data are queried in DataPave 2.0.)
Distribution Urgency (check one)
Resolution needed by:
checkbox                               (Date)
checkbox Next upload of affected data
Referred to: Assigned to: Information Copies to:
      Comments:
     
     
     
Action to be Taken: As recommended           As outlined below Date assigned:
Date due:
Findings/Actions Taken:
  Date completed:

Attach additional pages as necessary to describe situation, recommended action, and actions taken.

TO: Long-Term Pavement Performance Program
HRDI–13

6300 Georgetown Pike
McLean, VA 22101–2296
Facsimile: (202) 493–3161
Email: LTPPINFO@fhwa.dot.gov
LTPP

 

LTPP Data Analysis/Operations
Feedback Report
Report No.: RNS–3
Date: 15 September 1999
Submitted by: R. N. Stubstad, E. Lukanen, S. Tayabji and L. Clevenson
Subject: More LTPP FWD Load-Deflection Configuration Data Errors in Database
Situation:
In addition to the long-term sensor positioning errors outlined in Feedback Report RNS–2 (later RNS–2M), there are approximately 140 instances where a single set of data (non-time dependent) had one reported set of sensor positions in the configuration records, while in the field clearly another set was used. In most (but not all) cases, these errors were related to joint testing (J4, J5, C4 & C5). Some of these “instances” are overlapping, for example a J4 and J5 set of data in the same “day” file are both identified, so the number “140” is, to a certain extent, misleading. These are presented in a region-by-region format. Please note that the categorical errors—where d2 was positioned at –305 mm for joint tests, yet listed as +305 mm (this occurred quite frequently)—are not identified herein, since a global change in the database has reportedly been used to correct this error.
Recommended Action:
Revise configuration tables in the database to reflect the actual, not protocol, sensor positions, as identified on the enclosed diskette and outlined in the attached letter.
Distribution Urgency (check one)
Resolution needed by:
checkbox                               (Date)
checkbox Next upload of affected data
Referred to: Assigned to: Information Copies to:
      Comments:
     
     
     
Action to be Taken: As recommended           As outlined below Date assigned:
Date due:
Findings/Actions Taken:
  Date completed:

Attach additional pages as necessary to describe situation, recommended action, and actions taken.

TO: Long-Term Pavement Performance Program
HRDI–13

6300 Georgetown Pike
McLean, VA 22101–2296
Facsimile: (202) 493–3161
Email: LTPPINFO@fhwa.dot.gov
LTPP

 

LTPP Data Analysis/Operations
Feedback Report
Report No.: RNS–4M
Date: 30 September 2001
Submitted by: R. N. Stubstad, E.O. Lukanen and M.L. Clevenson
Subject: Inconsistent Deflection Basins of FWD Load-Deflection Records in the Current Data Tables.
Situation:
Feedback Form RNS–4 (dated September 1999) had listed a total of 7,045 individual FWD records (or lines) of data in the *.M06 files reported to have significantly large “random errors” or inconsistent deflection basins in the pre-autumn 1998 database. Meanwhile, all of the records that were associated with non-joint and non-J6 FWD test results and having one or more increasing deflections, as a function of distance from the loading plate, have now been flagged, in Column 24 (or X) in the current LTPP database, with a numeral “1”. The entire original list of 7,045 records has now been re-screened. Some of these records, where a potentially correct deflection basin had been previously identified as containing a random error, or if a previously identified record was not clearly inconsistent, are not identified in this Feedback Report. Also, none of the lines with increasing deflections is included in this list. As a result, a new list of 2,642 records of inconsistent deflection basins has now been re-identified for flagging in the FWD database. Please note that some of these 2,642 records, where single deflection readings were excessively large or small, may have already been altered in the current LTPP database using a blank field in the appropriate deflection column. Also please note that a few of these records may have already been deleted from the database, as previously suggested.
Recommended Action:
In Column 24 (or X) of the appropriate records in the FWD load-deflection database tables, please place a flag numeral “2” to indicate an inconsistent deflection basin, for reasons other than an increasing deflection basin (already flagged as a “1”), as per the accompanying Excel Spreadsheet "Inconsistent Deflection Basins – Sept. 2001.xls."  The data in the single Excel worksheet entitled "Feedback Summary" are organized by LTPP region. The first 23 fields in each of these records (or lines) are organized in a manner similar to the original *.M06 files obtained directly from the database (Data Release 9.0, dated 11/23/98). Additionally, in cases where any of the identified records, or any other record in the current database, already contains one or more deleted deflection readings, please place a “2” in Column 24 (or X) as well. This will assist the FWD load-deflection data analyst in identifying potentially inconsistent or incomplete deflection basins when carrying out bulk data processing. A letter explaining the Excel Spreadsheet in more detail is attached.
Distribution Urgency (check one)
Resolution needed by:
checkbox                               (Date)
checkbox Next upload of affected data
Referred to: Assigned to: Information Copies to:
      Comments:
     
     
     
Action to be Taken: As recommended           As outlined below Date assigned:
Date due:
Findings/Actions Taken:
  Date completed:

Attach additional pages as necessary to describe situation, recommended action, and actions taken.

TO: Long-Term Pavement Performance Program
HRDI–13

6300 Georgetown Pike
McLean, VA 22101–2296
Facsimile: (202) 493–3161
Email: LTPPINFO@fhwa.dot.gov
LTPP

 

LTPP Data Analysis/Operations
Feedback Report
Report No.: RNS–5
Date: 22 September 1999
Submitted by: R. N. Stubstad, E. Lukanen and L. Clevenson
Subject: Incorrect Duplicate Data and Other Error Lines of FWD Load-Deflection Data in Database
Situation:
There are approximately 12,000 individual records (or lines) of data in the *.M06 files, organized by region, test site and date of test, which are erroneous. The two main reasons for this are: 1) duplicate lines of data with incorrect time stamps or other errors in data entry, and 2) five occurrences of an entire day’s FWD tests conducted at the wrong LTPP test site. Other reasons include systematic deflection errors plus a few other infrequently occurring errors. The records that need to be deleted are organized as outlined in the attached letter. The approximately 12,000 records recommended for deletion from the database corresponds to some 0.28% of the total volume of FWD load-deflection data.
Recommended Action:
From the *.M06 files in the database, delete the various records of data from each LTPP Region as outlined in the attached letter and as presented in the enclosed comma delimited files of erroneous data records.
Distribution Urgency (check one)
Resolution needed by:
checkbox                               (Date)
checkbox Next upload of affected data
Referred to: Assigned to: Information Copies to:
LTPP TSSC 10/99   Comments:
Resolved for TSSC. Refer to RCOCs for action as recommended by TSSC.
  RCOCs 1/01  
     
     
Action to be Taken: As recommended           As outlined below Date assigned:
1/11/01
Date due:
3/23/2001
Findings/Actions Taken: Actions have been taken and the issues have been resolved.
  Date completed: 1/24/01

Attach additional pages as necessary to describe situation, recommended action, and actions taken.

TO: Long-Term Pavement Performance Program
HRDI–13

6300 Georgetown Pike
McLean, VA 22101–2296
Facsimile: (202) 493–3161
Email: LTPPINFO@fhwa.dot.gov
LTPP

 

LTPP Data Analysis/Operations
Feedback Report
Report No.: RNS–6
Date: 24 September 1999
Submitted by: R. N. Stubstad, E. Lukanen, S. Tayabji and L. Clevenson
Subject: Data Input (Individual Cell) Errors in the Load-Deflection Records in Database
Situation:
There are approximately 7,600 individual cells contained in about the same number of records (or lines) of data in the *.M06 files, organized by region and error type, which are erroneous. Most of these errors were manual data entry errors, such as Lane or Station Number. In many other instances, the date of test was incorrect due to reopening of an existing FWD data file on two successive dates. Finally, some time stamps were also incorrect (usually by one hour). The cells of data that need to be changed are organized as outlined in the attached letter. The approximately 7,600 cells recommended for change in the database affects some 0.17% of the total volume of FWD load-deflection data contained therein.
Recommended Action:
In the *.M06 files in the database, change the various records of data in each LTPP Region, as outlined in the attached letter and as presented in the 15 enclosed comma delimited files of erroneous data records.
Distribution Urgency (check one)
Resolution needed by:
checkbox                               (Date)
checkbox Next upload of affected data
Referred to: Assigned to: Information Copies to:
LTPP TSSC   Comments:
  RCOCs 01/11  
     
     
Action to be Taken: As recommended     X      As outlined below Date assigned:
1/11/01
Date due:
3/23/01
Findings/Actions Taken: Action has been taken and the issues have been resolved.
  Date completed: 1/24/01

Attach additional pages as necessary to describe situation, recommended action, and actions taken.

TO: Long-Term Pavement Performance Program
HRDI–13

6300 Georgetown Pike
McLean, VA 22101–2296
Facsimile: (202) 493–3161
Email: LTPPINFO@fhwa.dot.gov
LTPP

 

LTPP Data Analysis/Operations
Feedback Report
Report No.: RNS-7
Date: 30 September 2001
Submitted by: R. N. Stubstad, E.O. Lukanen and M.L. Clevenson
Subject: Use of Column X or 24 in the FWD Load-Deflection database Data Tables.
Situation:

Recently, Column 24 (or X) in the current LTPP database has been used to place a numeral “1” in cases of increasing deflections for non-joint associated FWD test results. This concept is expanded through the use of this column for a series of deflection basin codes, or warning flags. Two possible alternatives are:

Code Description Numeric Code Letter Code
a) Increasing deflections (for non-jointed tests) 1 I
b) Other inconsistent basin data (re. RNS–4M) 2 B
c) Non-protocol sensor positions (re. RNS–2M) 3 P
d) Other non-protocol but database recorded sensor position 3 P
e) Data evidently from incorrect test section (re. RNS–5) 4 S
Recommended Action:
In Column 24 (or X) of the appropriate records in the FWD load-deflection data tables, please place flags in the form of deflection basin or sensor position codes, as noted above and expanded upon in the accompany-ing cover letter. Note: A numeral "1" is already present in the database load-deflection data tables.
Distribution Urgency (check one)
Resolution needed by:
checkbox                               (Date)
checkbox Next upload of affected data
Referred to: Assigned to: Information Copies to:
      Comments:
     
     
     
Action to be Taken: As recommended           As outlined below Date assigned:
Date due:
Findings/Actions Taken:
  Date completed:

Attach additional pages as necessary to describe situation, recommended action, and actions taken.

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The Federal Highway Administration (FHWA) is a part of the U.S. Department of Transportation and is headquartered in Washington, D.C., with field offices across the United States. is a major agency of the U.S. Department of Transportation (DOT).
The Federal Highway Administration (FHWA) is a part of the U.S. Department of Transportation and is headquartered in Washington, D.C., with field offices across the United States. is a major agency of the U.S. Department of Transportation (DOT). Provide leadership and technology for the delivery of long life pavements that meet our customers needs and are safe, cost effective, and can be effectively maintained. Federal Highway Administration's (FHWA) R&T Web site portal, which provides access to or information about the Agency’s R&T program, projects, partnerships, publications, and results.
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