MEPDG Implementation: Arkansas

Transcription

1 MEPDG Implementation: Arkansas Kevin D. Hall, Ph.D., P.E. Professor and Head Dept. of Civil Engineering University of Arkansas 13 January 2008 Washington, DC

2 Where do you attack the Beast? Climate Materials Traffic Structure Damage Response Time Damage Accumulation Distress 2

3 Arkansas MEPDG Activities First Look Sensitivity Analyses Materials Characterization Hot mix asphalt Portland cement concrete Unbound materials Traffic Characterization Design Studies Local Calibration Research 3

4 Sensitivity Analyses Identify those inputs most critical in distress predictions Provided a head start to material characterization studies Numerous studies completed around the U.S. to date 4

5 Materials: Hot Mix Asphalt Dynamic Modulus (E*) 3 NMAS 3 Binder Grades 4 Agg Types 2 Gradations Created catalog of E* data for Level 1 design Assessed suitability of Level 3 predictive equation 5

6 Materials: PCC Coefficient of Thermal Expansion (CTE) Poisson s Ratio Modulus of Elasticity 5 Agg types Time Series Values Effect of Paste Catalog of Values Assessment of Predictive Relationships 6

7 Traffic Studies The Good 7 TTCs identified statewide Default monthly & hourly distribution factors suitable for use Developed statewide vehicle class distribution factors Developed statewide Axle Load Spectra The Bad TRAFLOAD could not be used; spreadsheets developed The Ugly Only 25 of 55 WIM sites suitable/comprehensive for traffic study Classification data: 17 of 25 sites passed quality checks Weight data: 10 of 25 sites passed quality checks 7

8 Design Studies Comparing designs with current practice Aid in identifying initial performance criteria Developing comprehensive database structure to integrate design, construction, performance / PMS data Developing Design Handbook 8

9 Example: Design Handbook General Traffic Inputs Mean wheel location Use default value shown Traffic wander std. deviation Use default value shown Design lane width Enter lane width in feet Average axle width Use default value shown Dual tire spacing Use default value shown Tire pressure(s) Use default value(s) shown Axle spacing(s) Use default value(s) shown 9

10 Local Calibration Efforts Potential existing section identification LTPP sites within Arkansas top 25 Superpave sites Primarily modified binders Guidelines for data collection: new construction Design Construction Performance Monitoring Database Construction 10

11 Database Structures 11

12 Climate Module: Database Structure MEPDG_Climate_Stations MEPDG_Climate_Hourly MEPDG_Climate_Daily MEPDG_Climate_Seasonal MEPDG_Climate_GWT_General MEPDG_Climate_GWT_Depth MEPDG_Climate_Elevation 12

13 Climate Module: Software Features Generate A Virtual Weather Station GPS Coordinates of Project Under Design Closest 6 Weather Stations & WTD Points Interpolation: Inversely Weighted by Distances Prepare *.icm File for Specific Design Summary Report: Show the Location of the Prepared Climate File Produce A Geo-Referenced Map to Show the Geographical Relationships 13

14 Climate Module: Geo Mapping Utility 14

15 Climate Module: User Software 15

16 Traffic Module: MEPDG Software 16

17 Traffic Module: Traffic Monitoring In Arkansas WIM Sites Vehicle Classification Sites Volume Count Only Sites Non-Operational Sites 17

18 Traffic Module: Database Structure MEPDG_Traffic_Stations_Yearly MEPDG_Traffic_Volume_Daily MEPDG_Traffic_Vehicle_Class_Monthly MEPDG_Traffic_Weight_Single_Monthly MEPDG_Traffic_Weight_Tandem_Monthly MEPDG_Traffic_Weight_Tridem_Monthly MEPDG_Traffic_Weight_Quad_Monthly 18

19 Traffic Module: QC Data Check (Vehicle Classification) Completeness of the Data Error in Dates, Months, State Code, etc Exactly 24 Hours A Day Days W/O A Single Vehicle QC Procedure (FHWA, LTPP, TRC 0402) Compare Manual Counts with WIM Data Check the # of Class 1 (Motorcycles) Check the # of Unclassified Vehicles Data W/O Significant Change 19

20 Traffic Module: QC Data Check (Vehicle Weight) Based on Class 9 Vehicles (Main Truck Type) QC Procedure Check the Weight of Front Axle Check the Weight of Drive Tandem Axle Check the Gross Vehicle Weights # of Vehicles Over the Legal Weight Limit 20

21 Traffic Module: Data Quality Control 21

22 Traffic Module: Software Features Generate Required 11 Traffic Files Based on TTC Class Six TTC Classes from TRC 0402 If No Idea: Statewide Average HFC: Preliminary Implementation Stage Summary Report to Show the Location of the Prepared Traffic Files A Geo-Referenced Map to Show the Geographical Relationships 22

23 Materials Module: Inputs General Inputs 4 Tables Asphalt Concrete (AC) 7 Tables Portland Cement Concrete (PCC) 5 Tables Stabilized Base 1 Table Unbound Materials / Subgrade 2 Tables Bedrock 1 Table 23

24 Materials Module: Retrieval Software Dynamic Modulus CTE M R 24

25 Project Files: Pavement Performance Ride (IRI) Distress - AC: cracking, rutting - JPCP: cracking, faulting - CRCP: punchouts Structure/Stiffness (FWD, GPR) Friction 25

26 Project Files: Construction Construction (11) Field Materials Sampling (4) AC Construction Related Testing (12) PCC Construction Related Testing (6) Stabilized Materials Construction Related Testing (2) Unbound Materials and Subgrade Construction Related Testing (7) 26

27 Project Files: Maintenance Seal Coats Crack Sealing Patching Joint Sealing Grinding Milling Grooving 27

28 Database Tables 28

29 Arkansas MEPDG Investment First Look Sensitivity Analyses complete $176 k Materials Characterization Hot mix asphalt complete $330 k Portland cement concrete ongoing $250 k Unbound materials ( complete )???? Traffic Characterization complete $ 81 k Design Studies ongoing $375 k Local Calibration Research (3 studies) Total Research Commitment (to date): $1.2M+ 29

30 Arkansas Bottom Line 30