Improved Penetrometer Performance in Stratified Sediment for Cost Effective Characterization, Monitoring and Management of Submerged Munitions Sites

Abstract

Geomechanical properties of seafloor surface sediment layers affect the characterization, assessment, and management of submerged munitions sites in multiple aspects. The overarching goal of project MR 18-1233 is the development and proof of concept of an improved framework for the deployment and data analysis of a portable free fall penetrometer (PFFP) in stratified sediments to assist with a cost-effective and rapid characterization, monitoring, and management of submerged munitions sites. The research strategy included field surveys, laboratory testing, data analysis and correlation, and the development of a novel investigation framework. The key findings of this project are: 1) Current methods of PFFP data analysis were improved and validated. Undrained shear strength can be estimated from PFFP for muddy seafloor sediments. Friction angles and relative density can be derived from PFFP for sandy seafloor sediments. 2) Significant variations in geomechanical properties within uppermost seabed surface layers were identified even without significant changes in sediment type. The results suggested that uppermost seabed surface layers may exhibit more suspension-like behavior than soil behavior depending on the water content. 3) The variability in geomechanical properties is of relevance to UXO site assessment and monitoring. 4) A novel PFFP deployment and analysis strategy was formulated that enables a rapid and cost-effective characterization of the upper meter of the seabed surface. The results provide a new insight into effects of geomechanical seabed soil layers on the interpretation of remotely sensed UXO site monitoring methods and UXO risk assessment.

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Document Details

Document Type
Technical Report
Publication Date
Jun 01, 2020
Accession Number
AD1135273

Entities

People

  • Carl T. Friedrichs
  • Grace M. Massey
  • Nina Stark

Organizations

  • Virginia Tech

Tags

Communities of Interest

  • Sensors

DTIC Thesaurus Topics

  • Data Analysis
  • Data Sets
  • Detection
  • Engineering
  • Geography
  • Grain Size
  • Law
  • Measurement
  • Mechanics
  • Munitions
  • Oceanography
  • Pore Pressure
  • Potomac River
  • Remote Sensing
  • Underwater Acoustics
  • Unexploded Ammunition
  • York River

Fields of Study

  • Environmental science

Readers

  • Acoustical Oceanography.
  • Geotechnical Engineering.
  • Systems Analysis and Design