Draft SOW - CWI System for NAPTF.pdf

Attachment A - Draft Statement of Work Coda Wave Interferometry (CWI) System

For National Airport Pavement Test Facility (NAPTF) Construction Cycle 10 (CC10)

1.0 Background

The Federal Aviation Administration (FAA) has a requirement for a system of in-pavement sensors that will detect and monitor internal structural damage in concrete airport test pavements based on the principle of coda wave interferometry (CWI). This system will be custom-designed for the National Airport Pavement Test Facility (NAPTF) and installed in a new concrete pavement test area designated Construction Cycle 10 (CC10). The system must provide reliable data throughout the planned five-year life of the test pavement.

The purpose of the CWI system in CC10 will be to detect and monitor internal damage such as bottom-up fatigue cracks before such damage becomes visible at the surface. Concrete pavements are designed to fail in fatigue, with small cracks originating at the bottom surface and gradually progressing toward the surface with additional traffic. The FAA intends to instrument a representative part of the test pavement with CWI sensors to monitor the progress of this damage. CWI is a novel method based on analysis of ultrasonic wave patterns. Unlike traditional “time-of-flight” wave analysis, which considers the pulse arrival time between pairs of embedded sensors, CWI analyzes the tail end of the signal (the “coda”). The coda wave appears chaotic but contains repeatable patterns that are sensitive to changes in structural properties, making CWI a suitable method for monitoring structural deterioration in concrete.

The NAPTF is a unique facility for full-scale testing of pavements subject to heavy aircraft traffic. Opened in 1999, the NAPTF features a rail-based test vehicle capable of simulating aircraft weighing up to 1.3 million pounds, with controlled aircraft wander. The NAPTF also has a fully automated computerized data acquisition system. More information is available at:

https://www.airporttech.tc.faa.gov/NAPTF. Test data from the NAPTF are analyzed and used to develop and improve FAA procedures for airport pavement thickness design and strength evaluation, contained in FAA Advisory Circulars (AC) 150/5320-6G and 150/5335-5D, and computer program FAARFIELD.

The NAPTF currently has several signal processing units (SPU) that capture pavement test data.

Each SPU houses a data collection unit, sensor terminations, terminal blocks, power supplies, and other necessary ancillary items. All SPUs are supported with a fiber optic line that connects to a network switch at each location. That network switch provides ethernet ports for external device connections. Each fiber optic line is a “home run” (i.e., continuous connection with no interruptions) directly to a main network switch in the computer server rack within the NAPTF Control Room. The NAPTF computer network is an isolated network and cannot be accessed from the internet.

https://www.airporttech.tc.faa.gov/NAPTF

2.0 Scope of Work

The scope of this work includes design, fabrication, installation, and initial data analysis of a CWI system for monitoring NAPTF CC10 concrete test pavements. Due to the specialized and experimental nature of CWI technology, all phases of the work from design through analysis must include a subject matter expert (SME) in CWI with specific experience in ultrasonic monitoring of concrete civil engineering structures using embedded sensors. All work must adhere to State and Federal safety regulations. (i.e., NEC, FCC).

2.1 Design Requirements:

Design of the CWI system must include, at a minimum:

• Number and location of all ultrasonic sensors.

• Additional sensor data that may be required to support the CWI analysis (e.g., thermocouples, moisture gages).

• List of all required system components, including part numbers and cut sheets, if applicable.

• Installation and Wiring Diagrams

• Data Collection Software Design and Documentation

• DAQ Program and Source Codes

• Schedule of activities including production, delivery and on-site installation.

2.1.1. Sensor Design and Layout

CWI sensors will be installed in the CC10 test area within the NAPTF. CC10 consists of three concrete pavement test items, each of 15 slabs (18 × 17.5 ft), separated by short transition areas.

Slabs are plain concrete, i.e., not reinforced. The thickness of concrete slabs in the three test areas is 13.5, 14.5 and 15.5 inches, respectively. The FAA intends to instrument one slab within each of the three test items with CWI sensors, and possibly a fourth slab in a location that will not receive wheel loads. The number of ultrasonic sensors in each slab must be sufficient to insonify the slab and localize damage. The ability to localize damage is critical because it is not known ahead of time exactly where the damage will appear within the instrumented slab. The total area of concrete to be insonified is approximately 1600 square feet.

The sensors must meet the following requirements:

• material must be compatible with Portland Cement Concrete (PCC).

• capable of surviving the five-year life of the experiment, as once installed, sensors and in-pavement electronics cannot be replaced.

• lead wire length customized for each sensor as needed.

• size must be comparable to other sensors currently in use to protect pavement integrity.

• CWI sensors and equipment within the slabs must be located to avoid conflicts with other in-pavement sensors (strain gages, thermocouples, corner displacement sensors, etc.).

2.1.2 Data Collection Hardware and Software

The Contractor must supply a turnkey Data Collection System (DCS) that meets the requirements of CC10 using the CWI sensors as described in section 2.1.1. The CWI data collection system must be mounted in a separate enclosure and function independently of the existing NAPTF DCS. The Contractor must coordinate the installation location of the system with the Government to ensure no interference with other systems.

The DCS must meet the following requirements:

• Connect to our local ethernet network.

• Operate from a computer in the control room.

• Provide capability to log data to local memory storage and to a network drive.

• Accept external trigger for start/stop data logging.

• Provide configuration utility for channels and sensor information and calibration factors.

• Data sampling timestamp included in data file.

• Appropriate Sampling rate for type sensors and experiment requirements

• Triggered via digital or analog inputs, or TCP/IP network command.

• Contained inside its own enclosure and enclosure mounted in wall or other approved location as per the Government.

• Provide protection for EMI noise.

The Contractor must coordinate with the Government on the CWI data collection software to either (a) ensure that all requirements can be met running CWI data collection software on an existing computer, or (b) define the requirements for new computer equipment if required. The Contractor must also coordinate with the Government on the operation of the data collection software. The Contractor must provide a full set of documentation that allows the Government to independently operate and understand how the software was designed.

2.2 Fabrication and Testing (Off-site)

Once the design has been completed and approved by the Government, the Contractor will fabricate the system off-site, including programming and testing the system. The Contractor must follow the approved design and build the CWI Data Collection System. Any changes to the design must be discussed with the Government. The final system must be accurately captured in as-built drawings in a format acceptable to the Government. The final system along with the as-built drawings will be required for Deliverable Item 4 – System Fabrication.

The Contractor must submit a test plan to the Government which identifies how the system will be tested. This plan and the results of the tests will be required for Deliverable Item 5 – System Testing (Off-site).

2.3 Installation and Testing (On-Site)

After the CWI Data Collection System has been fabricated and tested off-site, the Contractor will deliver the final system to the FAA William J. Hughes Technical Center NAPTF, B296, along with all required sensors, for installation and testing. The Contractor must install the sensors and the system. The installation of the sensors and the system must be coordinated with the Government and the designated CC10 Construction Manager. The final installation of the sensors and the system must be captured in as-built drawings. The Contractor will be required to note in writing any deviations from the accepted design. The as-built drawings and documentation will be required for Deliverable Item 6 – Sensor and System Installation.

The Contractor must submit to the Government an on-site test plan, which identifies how the CWI Data Collection System and sensors will be tested after installation. This plan along with the results of the tests will be required for Deliverable Item 7 – System Testing (On-site).

2.4 Data Analysis and Reporting

The Contractor must perform data analysis during the initial CWI System installation period and up to 1 year after the system is operational. During this time, the Contractor must provide the service of processing the data files, performing analysis, and reporting the data in an acceptable format approved by the Government. The Contractor must document this process such that the Government can follow and eventually perform these tasks independently. The Contractor must provide a recommendation for a data repository such that data can be accessed as efficiently as possible for this task. The process document along with analysis and data calls from the Government will be required for Deliverable Item 10 – Data Analysis and Reporting.

2.5 Training and Maintenance (Post-Installation)

The Contractor must provide training on how to use the CWI Data Collection System and process the data during the installation period and for the 1-year period after the system is operational. The Contractor must create all training documentation and provide the expertise for teaching the training content.

The Contractor will be responsible for providing all maintenance for one year after system implementation. This includes all aspects of the system and those items that may be required to do the analysis and reporting of the data.

5.0 Deliverables

ITEM DELIVERABLE DUE DATE

1 REQUIREMENTS

COLLECTION

TBD

2 SENSOR PLACEMENT TBD

3 SYSTEM DESIGN TBD

4 SYSTEM FABRICATION TBD

5 SYSTEM TESTING (OFF-

SITE)

TBD

6 SYSTEM INSTALLATION TBD

7 SYSTEM TESTING (ON-SITE) TBD

8 SYSTEM DOCUMENTATION TBD

9 SYSTEM OPERATIONAL

TRAINING

TBD

10 DATA ANALYSIS AND

REPORTING

TBD

11 DATA ANALYSIS TRAINING TBD

12 SYSTEM MAINTENANCE TBD

6.0 Period of Performance

The base performance for this project is 24 months from the date of award. Performance is estimated to start in May 2024.

7.0 Place of Performance

The work will be completed at the contractor’s facility and onsite at the William J. Hughes Technical Center, B296 as required by the contract deliverables.

8.0 Travel

The contractor should assume travel for all deliverables and Government held meetings. The Government will determine later specifically when the Contractor is required to be on-site.