Presented by: Ben Brown, PE

Transcription

1 Presented by: Ben Brown, PE

2 What is Automated Machine Guidance?

3 What is mmgps? Automated Machine Guidance (AMG) The Use of Global Positioning System (GPS) technology to guide and control construction equipment AMG for Paving and Milling Topcon s system is mmgps Trimble s system is Trimble 3D Leica s system is PaveSmart 3D Accuracy is increased through secondary receiving station Trimble, Topcon and Leica use robotic total station Topcon can also use Positioning Zone Laser GPS sensors integrate with the machine s electronic controls 3D project model loaded into control box. Sensors adjust screed and mill elevations to match the model at a given location

4 Asphalt Paver 3D-mmGPS 1. PZS MC Sensor 2. Slope Sensor 3. GX-60 Control Box 4. MC-R3 GPS Receiver

5 AMG paving operation

6 Milling 3D-mmGPS 1. Hydraulic Valve Assembly 2. MC-R3 GPS Receiver 3. PZS-MC Sensor 4. Slope Sensor 5. GX-60 Control Box

7 AMG Control box attached to milling machine

8 AMG milling operation

9 AMG milling operation with Positioning Zone Laser station in foreground

10 OOCEA Project SR 417 Widening from SR 528 to Curry Ford Road

11 OOCEA Project SR 417 Widening from SR 528 to Curry Ford Road Before After

12 Why Automated Machine Guidance? Project design required cross-slope and profile correction Transition from 2 lanes to 3 lanes plus auxiliary required modification of cross-slope Existing profile deficiencies to be corrected Pavement optimization required complexity 43 Milling control point transitions SB (12 inside to outside) 46 Milling control point transitions NB (11 inside to outside) Limit to production Opportunity to introduce errors Increase pavement joints Quality control and quantity tracking more difficult Project anticipated significant quantity for overbuild asphalt 8,203.4 TN at $61.50/TN for a total cost of $504, Overbuild quantity is estimated but not limited contractually Significant thickness of overbuild posed constructability challenge Extensive overbuild presented a potential quality concern Overbuild would replace sound pavement to be milled out

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14 Why Automated Machine Guidance? Milling Details

15 Why Automated Machine Guidance? Milling Details

16 Why Automated Machine Guidance? Milling Control Points

17 Why Automated Machine Guidance? Project design required cross-slope and profile correction Transition from 2 lanes to 3 lanes plus auxiliary required modification of cross-slope Existing profile deficiencies to be corrected Pavement optimization required complexity 43 Milling control point transitions SB (12 inside to outside) 46 Milling control point transitions NB (11 inside to outside) Limit to production Opportunity to introduce errors Increase pavement joints Quality control and quantity tracking more difficult Project anticipated significant quantity for overbuild asphalt 8,203.4 TN at $61.50/TN for a total cost of $504, Overbuild quantity is estimated but not limited contractually Significant thickness of overbuild posed constructability challenge Extensive overbuild presented a potential quality concern Overbuild would replace sound pavement to be milled out

18 How to implement AMG Contract modified to allow for automated machine guidance Replace FDOT Standard Spec. 327 Milling of Existing Asphalt Pavement Specify milling to establish required elevation +- ¼ Replaced fixed depth milling pay items with variable depth pay items Significant survey effort required for final surface design You will be modeling the final surface in 3D, so better initial information will give better results and more accurate quantity estimates You will build the project from the model down rather than from existing up In our case, hard shots were collected every 25 along all existing lane lines Develop Model of proposed surface Model existing pavement surface Model proposed pavement surface Export both models into a table Use table to confirm that cuts/ fills constructible Must determine maximum allowable cut (must maintain structural integrity) Special attention required at bridge approaches and ramp convergence Compare adjacent lanes for potential drop-off violations between lanes Change the proposed model and confirm again until all parties satisfied Cooperation of Owner, Contractor and Engineer of Record a must Only proceed when all parties have buy-in of model

19 Confirming the Model Table created from the output of the models to compare elevations of the proposed surface to the existing pavement elevations.

20 How to execute AMG? Approved model is loaded into control box Confirm proper configuration of gear and base station Proceed with work Technician loads model into control box Confirm proper grades with rover Confirm accurate elevations with preplaced grade markers in shoulder Surveyor confirms grade of milled surface while Inspector confirms cross-slope

21 How to monitor AMG Typical Milling Limerock Base When the milled surface is within the red lines, meaning all the friction course has been removed and the minimum thickness of structural asphalt has been maintained, asphalt paving operations should proceed immediately behind the mill.

22 How to monitor AMG Overbuild Section Limerock Base When the milled surface is above the top red line, meaning the mill has aired out or failed to remove all the friction course, a second pass with the milling machine is required to remove all friction coarse before asphalt paving operations should proceed. Areas under this scenario will require an overbuild course for leveling before structural asphalt can be placed.

23 How to monitor AMG Undercut Section Limerock Base When the milled surface is below the bottom red line, meaning the remaining structural asphalt is too thin to provide the minimum structural value, a second pass with the milling machine is required to remove additional structural asphalt and base to be replaced with structural asphalt. Areas under this scenario two lifts of structural asphalt will be required.

24 How to monitor AMG? Milling machine used to remove base material to be replaced with asphalt, so that the required structural number for the roadway will be maintained.

25 What were the benefits? Ride Quality is excellent All transitions are machine guided Quality of the pavement was improved Required overbuild pavement was greatly reduced. Most asphalt placed in uniform lifts. Where overbuild was needed, the paver was equipped with AMG Milling and Paving phased efficiently Working from the model allowed paving operations to work the length of the project in a circuit. Improved safety with only a single MOT set up each night Paving operations completed in fewer shifts Less impact to customers Less overhead and inspection cost Reduction in the use of overbuild Anticipated quantity of 8,203.4 TN was reduced to 2500TN At $61.50/TN this resulted in savings of over $350,000

26 Text Completed Slide SR 417 Project Lorem ipsum dolor sit amet Consetetur sadipscing elitr Sed diam nonumy eirmod tempor Invidunt ut labore et dolore magna Aliquyam erat, sed diam voluptua At vero eos et accusam et justo duo Et ea rebum Stet clita kasd gubergren No sea takimata sanctus est Lorem ipsum dolor sit amet Invidunt ut labore et dolore magna Aliquyam erat, sed diam voluptua

27 Presented by: Ben Brown, PE Questions?