Monitoring for Bridge Scour - Phase 3 Installation

Monitoring for Bridge Scour Phase 3 Installation PennDOT Technical Advisor:

Paul Koza

Principal Investigator:

Dr. Ervin Sejdic

Graduate Students:

Nicholas Franconi Michael Rothfuss 1

 Introduction  Requirements

 Design  Installation  Discussion  Conclusion

2003 – Montezuma Creek Utah

2009 – Malahide Dublin

What is Bridge Scour?

2015 – I-10 California 2

 Introduction  Requirements

 Design  Installation  Discussion  Conclusion

Scour Code Description  8 ‐ Bridge foundations determined to be stable for the assessed or calculated scour condition.  6 ‐ Scour calculation or evaluation has not been made  5 - Bridge foundations determined to be stable for assessed conditions  4 - Bridge foundations determined to be stable for assessed scour conditions but field review indicates action is required  3 to 0 ‐ Bridge is scour critical; bridge foundations determined to be unstable  U ‐ Bridge with unknown foundation that has not been evaluated for scour.

The National Bridge Inspection Standards require highway bridge inspections every 24 months

A bridge is classified as “structurally deficient” and in need of repair if the rating for a key structural elements is 4 or below

Bridge Scour Assessment

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In the United States…  Over 200 million trips are taken daily across structurally deficient and functionally obsolete bridges in the 102 largest metropolitan U.S. regions.  Introduction  Requirements

 Design  Installation

 As of 2015, Pennsylvania has the 4,783 structurally deficient bridges

 In 2013, the American Society of Civil Engineers assigned a grade of C+ to the Nation’s bridges

 While conditions of bridges have steadily improved, the 2015 National Bridge Inventory reported:  58,000 structurally deficient bridges  84,000 functionally obsolete bridges

 Discussion  Conclusion

 The FWHA estimates that to eliminate the bridge backlog by 2028, an investment of $20.5 billion would be required annually.

Bridge Scour Statistics

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 Introduction Tilt Sensor

 Requirements

 Design

Electrical Conductivity

 Installation  Discussion  Conclusion

Sonar Scour Monitor

Example data from Sonar Mapping

Techniques for Monitoring Scour

Float-out Device

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 Introduction  Requirements

 Design  Installation  Discussion  Conclusion

Techniques for Monitoring Scour

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 Introduction  Requirements

 Design

Requirements

 Installation  Discussion  Conclusion

• Goals  Mechanical and electrical float-out specifications  Lifetime and indicators for RF receiver

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PennDOT Requirements

 Introduction  Requirements

 Design  Installation  Discussion  Conclusion

RF Receiver  Low Power  Continuously Operating  Custom Light Indicator  Durable Enclosure

Float-Out Device  Tilt Sensitive Activation  Conforms to FCC Regulation  External Magnetic Switch  Unique Serial Number

Float-out and Receiver Requirements

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 Introduction  Requirements

 Design

Design

 Installation  Discussion  Conclusion

• Goals  Overview of float-out electronics  Float-out collision avoidance, and construction durability testing  Overview of receiver electronics  Receiver electronics validation

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Receiver PCB

RF Receiver with Off-Grid Power

Charge Controller

 Introduction  Requirements

 Design  Installation

Software Architecture

 Discussion  Conclusion

Power Consumption Calculations

RF Receiver Design

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 Introduction

• Key Float-out Improvements  Passive Reset Switch  Extended 20 Year lifetime  Automated false trigger reset  No external reset switch

Power Enable and Reset Circuitry

 Requirements

 Design

Float-out Device Hardware Architecture

 Installation

Voltage Regulator

 Discussion

Power Enable

 Conclusion

RF Microcontroller Power Amplifier

Passive Tilt Sensitive Switch

Antenna

Float-out Device Design

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• Collision Avoidance Algorithm  Custom ALOHA NET Algorithm  Transmit Period (T) of 2.5 milliseconds  Pseudo-Random seeded from Serial Number  Introduction

PseudoRandom Number Generation Transmit Scour Data Packet

 Requirements

 Design

Bridge ID #

 Installation

Wait Predetermined Period of Time

Scour Data Packet Serial # Scour Loc.

Scour Depth

Possible Float-out Devices = 216 = 65536 devices

 Discussion  Conclusion

• Complies with FCC Regulation  Maximum Transmit Power - 16.47 dBm  Power Spectral Density - 6.72 dBm/3 kHz  6 dB Bandwidth - 513.25 kHz

Testing of the Float-out Devices

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Float-Out Devices Painted and Labeled for Installation

 Introduction  Requirements

 Design  Installation  Discussion  Conclusion

• Float-Out Testing Procedure  Reset RF Receiver  Removal of magnet to activate ARM State  Tilt Float-out 90 degrees to activate ON State  Verify scour indication  Re-secure magnet

Final Testing Procedures

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 Introduction  Requirements

 Design

Installation

 Installation  Discussion  Conclusion

• Goals  Receiver Installation  Float-out Device Installation

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 Introduction  Requirements

• PennDOT Selected Bridge  Covers Pine Creek  Scour present at bridge  Armstrong County  SR 1028 Segment 240  Bridge ID #: 03102802400395

 Design  Installation  Discussion  Conclusion

• Scour location Selection Process  Location 1 – Significant scour present  Location 2 – Significant scour present  Location 3 – Scour expected to occur  Location 4 – No expected scour

Bridge Location Information

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 Introduction

Due to the age of the bridge (1923), limited documentation is available, specifically relating to the supporting structures.

 Requirements

 Design  Installation  Discussion  Conclusion

Bridge Documentation

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L.G. Hetager Drilling was contracted to perform the installation in November, 2015.

 Introduction  Requirements

 Design  Installation  Discussion  Conclusion

Gardner Denver articulated drill rig track mount.

Articulating rig with geotechnical mast, tooling, and platform extending over the bridge

Float-out Device Flush Casing Drill Rig

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Float-out Installation 1. Prepare backfill 2. Drill to 8 foot depth 3. Lift drill by 8 inches 4. Test Float-out Device 5. Lower Float-out Device 6. Hold in position with Tamper 7. Backfill appropriate quantity 8. Repeat Steps 3-7 until completed

 Introduction  Requirements

 Design  Installation  Discussion  Conclusion

Float-out Installation Jig

In slow water, float-out devices remained under the bridge, however in flood conditions, the capsule should be carried downstream.

Installed Float-out Device Locations

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 Introduction  Requirements

 Design  Installation  Discussion  Conclusion

Backfill Calculations

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 Introduction  Requirements

 Design  Installation  Discussion  Conclusion

Antenna Orientation and Receiver Installation

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 Introduction

Antenna Selection  Directional Patch Antenna Trade-offs  Facing downstream for Maximum Coverage  Successful communication to tree line (~500 ft.)  Unable to receive signal from upstream installation location due to antenna orientation

 Requirements

 Design  Installation  Discussion  Conclusion

Distance Testing of float-out device and Antenna Orientation

Antenna Orientation and Receiver Installation

LEDs visible in daylight after button press

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Significant debris downstream cause the float-out device to be trapped in slower moving water

 Introduction  Requirements

 Design  Installation  Discussion  Conclusion

Antenna Orientation and Receiver Installation

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 Introduction  Requirements

 Design  Installation  Discussion  Conclusion

 The proposed scour configuration requires a total drilled depth of 8 feet.  The drill time for Location 1, Location 2, and Location 4 was approximately 45 minutes.  Location 3 took approximately 90 minutes to drill, due to a boulder  The installation of each individual float-out device took approximately 15 minutes.

 The use of multi-depth float-out devices is impractical for monitoring purposes  Float-out devices will outlast the RF receiver solar panel and battery backup system  The float-out capsules in quantity will cost under < $100/device in parts  Due to solar panel and battery, receiver is significantly more expensive ~$2,000

Float-out Installation Discussion

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• Conceptual Map of Scour Database  Bridges monitored remotely  Not limited to float-out monitoring  Big data processing to aide in detection  Event Prediction  Introduction  Requirements

 Design  Installation

Birmingham Bridge

Location 4 Start Scour Depth: 1 foot GPS Latitude: 40.434176 GPS Longitude: -79.973581

Location 1 Location 2 Location 3 Location 4

 Discussion  Conclusion

Location 4 – Level 3 Serial Number: 0x0000 Depth Indicator: Orange Scour Depth: 8 Feet GPS Latitude: 40.434176 GPS Longitude: -79.973581 Installation Date: 09/27/2015 Release Date: 09/27/2015 Additional Bridges: Bridge 1 / Time 1 Additional Bridges: Bridge 2 / Time 2

IoT Implementation of Bridge Monitoring

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 Introduction  Requirements

 Design

Conclusion

 Installation  Discussion  Conclusion

• Goals  Low Cost solution for monitoring scour  Low maintenance Solution  Designed for shallow water ways and rural bridges  Improvements to the system can be made by reducing lifetime

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 Introduction  Requirements

 Design  Installation

Questions?

 Discussion  Conclusion

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