Implementation of NCHRP Research Report 887 - Guidance for Underwater Installation of Filter Systems

The purpose of NCHRP Project 24-42 was to provide specific guidance for design, construction, and maintenance personnel on the function of filters and their installation. The research considered various depths and velocities of stream flow for placing geotextiles and granular filters under countermeasures with emphasis on underwater installation. NCHRP Project 24-42 was completed with the publication of NCHRP Report 887 "Guidance for Underwater Installations of Filter Systems" (2018) and a companion implementation document "Training Manual for Underwater Installation of Filter Systems" (NCHRP Web-Only Document 254, Volume 2). The research successfully demonstrated that a variety of materials and placement methods exist for installing filter systems underwater and, specifically, in flowing water. Filter systems are an integral and critical component of countermeasures designed to mitigate bridge scour and erosion. A primary concern of many state DOTs is that in practice, filter systems are often eliminated from a construction project by a field change during construction when underwater installation is required. The most common reasons given for the omission of a filter have been related to constructability issues or environmental concerns. Based on this research, NCHRP Report 887 concludes: "There should be very few instances where a filter cannot be placed underwater as an integral part of a properly designed and installed scour or erosion control countermeasure." The practical information and lessons learned from this research project regarding materials and methods involved in placing filter systems underwater will be of immediate interest to practitioners. In particular, designers, specifiers, resident engineers and construction contractors will appreciate not only the need for properly installed filters, but also the advantages and limitations of various equipment and techniques available in the US to achieve successful placement, thus ensuring long-term performance. Under Implementation Project 20-44(14) the NCHRP 24-42 Training Manual was used to support a 1-day Workshop that was conducted in Fort Collins, CO on October 10, 2019 to make the results of NCHRP Project 24-42 available on an expedited basis to a select group of state highway agencies, FHWA staff, and consultants. This implementation activity provided a unique "train the trainers" opportunity. Workshop attendees were provided the resources (i.e., a 120 page Instructor's Guide, 100 supporting Power Point® slides, and a 7 minute video clip) and the knowledge to return to their agencies and provide essential training on underwater installation of filters to their associates, consultants, and contractors.


  • English


  • Status: Completed
  • Funding: $50000
  • Contract Numbers:

    Project 20-44(14)

  • Sponsor Organizations:

    National Cooperative Highway Research Program

    Transportation Research Board
    500 Fifth Street, NW
    Washington, DC  United States  20001

    American Association of State Highway and Transportation Officials (AASHTO)

    444 North Capitol Street, NW
    Washington, DC  United States  20001

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Project Managers:

    Mohan, Sid

  • Performing Organizations:

    Ayres Associates

  • Principal Investigators:

    Clopper, Paul

  • Start Date: 20190325
  • Expected Completion Date: 20200324
  • Actual Completion Date: 0

Subject/Index Terms

Filing Info

  • Accession Number: 01712952
  • Record Type: Research project
  • Source Agency: Transportation Research Board
  • Contract Numbers: Project 20-44(14)
  • Files: TRB, RiP
  • Created Date: Jul 29 2019 3:26PM