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FWD Deflection Data Analysis and Backcalculation Tool: BcT 15 August 2017

FWD Deflection Data Analysis and Backcalculation Tool Presenters: Moderator: John Donahue; MoDOT & Chairperson, AASHTOWare ME Design Task Force Harold L. Von Quintus, P.E., ARA Yanbin Zhang, ARA Dinesh Ayyala, ARA Presentation will be available for viewing on the ME-Design Resource website: http://www.me-design.com Judy: Introduce the presenters and announce where the presentation can be downloaded for future reference.

FWD Deflection Data Analysis and Backcalculation Tool Phones are being muted. Questions can be asked through the chat box The presenters will answer all questions at the end of the demonstration. Any question not answered because of time, will be answered after webinar and submitted to individual asking question.

Process for Enhancing the Software: Suggested revisions are received from users and AASHTO members. Pavement ME Design Task Force monitors on-going/completed NCHRP, FHWA, and pool fund projects applicable to the MEPDG. Pavement ME Design Task Force members review and prioritize all potential suggested revisions and enhancements. Judy: Overviews the activities of the task force for deciding what enhancements get done and turns presentations back to Chad.

Pavement ME Task Force Members John Donahue, P.E.; Missouri DOT, Chairperson Vicki Schofield, AASHTO Project Manager Jay Goldbaum, P.E.; Colorado DOT Marta Juhasz, P.E.; Alberta Transportation Clark Morrison, P.E., North Carolina DOT Robert Shugart, P.E.; Alabama DOT Felix Doucet; TAC Liaison Tom Yu, P.E.; FHWA Liaison Shane Marshall, P.E.; Utah DOT, SCOJD Liaison Jack Dartman, Montana DOT; T&AA Liaison

FWD Deflection Data Analysis and Backcalculation Tool Before we get started: Poll Questions #1 and #2 Chad: Brings up the poll question and summarizes the results.

FWD Deflection Data Analysis & Backcalculation Tool for Pavement ME Presentation of BcT; an Overview: Background Information Products Overview and Features of the Tool Release Information Demonstration of Tool Questions and Answers

Background AASHTO Pavement ME Task Force Direction: Develop a comprehensive tool to analyze and format deflection data, perform backcalculation and generate Pavement ME input files for rehabilitation design. Backcalculation program is executed independently, but output is formatted according to Pavement ME input requirements. Two versions of program: English based units SI based units

Background Backcalculation software packages requested and considered for use; AASHTO required source code. EVERCALC source code provided by Washington DOT; a special thank you to: Jeff Uhlmeyer, Washington DOT Nadarajah Sivaneswaran (Siva), FHWA Linda Pierce, Nichols Consulting Engineers

Background Input and analysis considerations from other projects. Backcalculation of LTPP Deflection Data; Report FHWA-HRT-15-036 FHWA Contact: Jane Jiang Charaterization of Existing HMA Layer for ME Pavement Rehab. Design DTFH61-14-C-00024 FHWA Contact: L. Wiser AASHTO FWD Deflection Analysis & Backcalc. Tool for Use with Pavement ME Design Backcalculation of Layer Parameters; Report FHWA-RD-01-0113 FHWA Contact: C. Richter MEPDG User Manual Multiple other Projects Sponsored by State Agencies & FHWA.

FWD Deflection Data Analysis & Backcalculation Tool for Pavement ME Presentation Overview: Background Information Products Overview and Features of the Tool Release Information Demonstration of the Tool Questions and Answers

Products User information in support of Pavement ME input level 1 rehabilitation design: Software or the analysis package; separate from the Pavement ME software. Documents User Manual; compliments the MEPDG Manual of Practice. Extracted chapters from the EVERSERIES Manual related to backcalculation.

FWD Deflection Data Analysis & Backcalculation Tool for Pavement ME Presentation Overview: Background Information Products Overview and Features of the Tool Release Information Demonstration of the Tool Questions and Answers

Overview and Features of Tool Backcalcuation program is run independently but the output is formatted in accordance with Pavement ME input requirements. Parts or utility tools in support of Pavement ME Design Part 1—Preprocessing Deflection Data Tool for Backcalculation Part 2—Backcalculation of layered elastic moduli Part 3—Post processing backcalculation results for generating Pavement ME inputs.

Overview and Features of Tool Input FWD Data Segmentation Sensors Preliminary Segmentation Statistical Comparison Final Segmentation Structure Definition Backcalculation Physical Features Export to ME Design

Overview and Features of Tool Guides the user through the process, and provides a description of the feature and its function; similar to Pavement ME.

Overview and Features of Tool BcT Help Manual

Part 1: Preprocessing Deflection Data 1. Import Raw FWD Data File 2. Cleanup and Filtering 3. Segmentation 4. Pavement Structure Definition Generate input files using pre-processed data File format is compatible for use with EVERCALC® Generation of Input Files for EVERCALC

Part 1: Preprocessing Deflection Data 1. Import FWD Data File Convert file into one standard format for backcalculation. Five FWD file format converters: KUAB – .FWD JILS – .DAT Dynatest – V20 (*.FWD) Dynatest - F20 (*.F20) Dynatest – V25 (*.F25)

Part 1: Preprocessing Deflection Data Read FWD data file Data organized and displayed through three tables: Upper table contains a list of stations and attributes (temperatures, elevation, etc.). Middle table shows the sensor configuration. Lower table shows deflection data at all drops for the station selected in upper table. 1. Import FWD Data File

Part 1: Preprocessing Deflection Data Program classifies deflection basins into four types: Typical Type 2 – Significant decrease in deflection between two adjacent sensors Type 1 – Deflections at some sensors greater than D0 Type 3 – Non- decreasing deflection at adjacent sensors 2. Data Cleanup and Filtering

Part 1: Preprocessing Deflection Data Typical Type 1 Normalized Deflection Basin Types Type 2 Type 3 Source: Von Quintus and Simpson (1998)

Part 1: Preprocessing Deflection Data Filter for deflection charts: Drop Load Test Type Basin Characterization Lane/Direction Sensors; Defl. Charts 3. Segmentation

Part 1: Preprocessing Deflection Data Preliminary Segmentation: Automatic process based on cumulative area method. Used in MODULUS Statistical comparison for segments: F-test: Test for variance t-test: test for means 1 2 3 4 1 2 3 4 5 1 2 3 4 5 3. Segmentation

Part 1: Preprocessing Deflection Data Cursor used to manually define the location of each segment. Final segments selected by user. 1 2 3 4 3. Segmentation

Part 1: Preprocessing Deflection Data Evercalc Inputs: Layer # Layer Type Thickness Poisson’s Ratio Min. E Max. E Seed E 1 2 3 4 4. Structure Definition

Part 2: Backcalculation Input Files Generated from preprocessed data Backcalculation process is EVERCALC® Output File Pavement layer moduli and other parameters Separate output file for each individual segment. Results – backcalculated moduli for each pavement layer and RMSE displayed as charts on the interface. No user activity – process is completely automated.

Part 2: Backcalculation Compensating Layer Effects Layer Elastic Modulus Sensors used in backcalculation. Root Mean Squared Error Review Backcalculation Results

Part 2: Backcalculation Based on RMSE and backcalculated modulus value Criterion Acceptable Atypical Unacceptable RMSE ≤3.0 3 to 5 >5.0 Modulus Within Acceptable range limits Outside acceptable but within atypical limits Outside Atypical range limits Acceptable Atypical Error

Part 2: Backcalculation Compensating Layer Effects User makes decision on whether structure needs to be changed because of compensating layer effects Use graph to check for the E upper or lower boundary limits. Compensating Layer Effects

Part 2: Backcalculation Load Transfer Efficiency Two sensors used for LTE. LTE for HMA and PCC: defined by LTPP. Void Analysis: defined by 1993 AASHTO Void Analysis Physical Features

Part 2: Backcalculation; Physical Features LTE for HMA & PCC: defined by LTPP. Void Analysis: defined by 1993 AASHTO

Part 3: Post-Processing of Backcalculation Results Input Files Intermediate text files from backcalculation Post-processing & summarization of results Output File DGPX file as input to Pavement ME for rehab design Summarize individual drops and segment average results – displayed on the interface in Export to ME Design tab. Summary includes analysis statistics such as RMSE and quality of convergence. Post-processor generates an output DGPX (.dgpx) file.

Part 3: Post-Processing of Backcalculation Results Export to ME Design: Layer description tied back to default materials in Pavement ME. Average E for each layer. Standard deviation and coefficient of variation included in summary. LTE, temperature, and frequency included as outputs.

FWD Deflection Data Analysis & Backcalculation Tool for Pavement ME Presentation Overview: Background Information Products Overview and Features of the Tool Release Information Demonstration of the Tool Questions and Answers

Release Information Released July 2017 with Pavement ME Design software, along with the User Manual. Authorization code tied to license for Pavement ME Design.

BcT Software Software and documentation can be downloaded from AASHTWare web site http://www.me-design.com

BcT Software

BcT Software

BcT User Manual

FWD Deflection Data Analysis & Backcalculation Tool for Pavement ME Poll Question #3 Chad: Brings up the poll question and summarizes the results.

FWD Deflection Data Analysis & Backcalculation Tool for Pavement ME Demonstration of BcT for Rehabilitation Design

FWD Deflection Data Analysis & Backcalculation Tool for Pavement ME Poll Questions #4, #5, and #6 Chad: Brings up the poll question and summarizes the results.

Question and answer Session AASHTOWare: Pavement ME Design FY17 Enhancement Question and answer Session We welcome comments & suggestions for future webinars; Send an email to pavementmedesign@ara.com. Harold – moderates the question and answer period.

FWD Deflection Data Analysis & Backcalculation Tool for Pavement ME Design Remember the Pavement ME Design Users Group Meeting scheduled for October 11 and 12, 2017 in Denver, CO.

Thank you for Attending the Webinar! AASHTOWare Pavement ME-Design Contacts: Vicki Schofield, AASHTO vschofield@aashto.org Phone: (202) 624-3640 John Donahue, MoDOT John.donahue@modot.gov ME Design Resource Website http://www.me-design.com Pavement ME Design Users Group Contact: Christopher Wagner, FHWA Christopher.wagner@dot.gov Phone: (404) 562-3693 Help Desk, Customer Support: ARA Staff: Deepak Raghunathan, ARA Inc. draghunathan@ara.com Phone: (217) 356-4500 Biplab Bhattacharya, P.E. bbhattacharya@ara.com Other ARA Staff: Chad Becker cbecker@ara.com Harold Von Quintus, P.E. hvonquintus@ara.com Michael I. Darter, P.E. Mdarter@ara.com Harold: Identify the AASHTOWare contacts and thanks everyone for participating. Judy: Thanks everyone for participating in the webinar.