0 TECHNICAL REPORT HL-84-6 föftf / -AGITATION DREDGING: LESSONS AND GUIDELINES FROM PAST PROJECTS by Thomas W. Richardson Hydraulics Laboratory DEPARTMENT OF THE ARMY Waterways Experiment Station, Corps of Engineers PO Box 631 Vicksburg, Mississippi 39180-0631 July 1984 Final Report Approved For Public Release; Distribution Unlimited Prepared for DEPARTMENT OF THE ARMY US Army Corps of Engineers Washington, DC 20314-1000 LIBRARY MAR 1 5 -1985 Bureau ot Reclamation Denver, Colorado Destroy this report when no longer needed. Do not return it to the originator. The findings in this report are not to be construed as an official Department of the Army position unless so designated by other authorized documents. The contents of this report are not to be used for advertising, publication, or promotional purposes. Citation of trade names does not constitute an official endorsement or approval of the use of such commercial products. BUREAU OF RECLAMATION DENVER LIBRARY Æ 92012004 ' Unclassified SECURITY CLASSIFICATION OF THIS PAGE (When Data Entered) READ INSTRUCTIONS REPORT DOCUMENTATION PAGE BEFORE COMPLETING FORM 1. R E P O R T NU M B ER 2. GOVT ACCESSION NO. 3. R E C IP IE N T ’ S C A T A L O G N U M B ER Technical Report HL-84-6 4. T IT L E (and Subtitle) 5. TYPE OF REPORT & PERIOD COVERED AGITATION DREDGING: LESSONS AND GUIDELINES FROM Final Report PAST PROJECTS 6. PERFORMING ORG. REPORT NUMBER 7. AUTHOR*» 8. CONTRACT OR GRANT NUMBER*» Thomas W. Richardson 9. PERFORMING ORGANIZATION NAME AND ADDRESS 10. PROGRAM ELEMENT, PROJECT, TASK AREA & WORK UNIT NUMBERS US Army Engineer Waterways Experiment Station Hydraulics Laboratory PO Box 631, Vicksburg, Mississippi 39180-0631 11. CONTROLLING OFFICE NAME AND ADDRESS 12. R E P O R T D A T E DEPARTMENT OF THE ARMY July 1984 US Army Corps of Engineers 13. NU M B ER O F PAGES Washington, DC 20314-1000 141 14. MONITORING AGENCY NAME & ADDRESS*1// different from Controlling Office) 15. S E C U R IT Y CLASS, (of thia report) Unclassified 15*. DECLASSI FICATION/DOWNGRADING SCHEDULE 16. DISTRIBUTION STATEMENT (of this Report) Approved for public release; distribution unlimited. 17. D IS T R IB U T IO N S T A T E M E N T (of the abstract entered in Block 20, if different from Report) 18. SUPPLEMENTARY NOTES Available from National Technical Information Service, 5285 Port Royal Road, Springfield, Virginia 22161. 19. K E Y WORDS (Continue on reverae aide if neceaaary and identity by block number) Agitation Dredging (WES) Dredges (LC) Dredging (LC) 120k A B STR A C T CGant&nie eat re ver me s£tdt ft nece-eemry and id e n tity by block number) This report is based on a comprehensive literature survey of agitation dredging projects and the field data obtained from a small-scale monitoring study. Twenty-two agitation dredging projects are described from the stand­ points of technical performance, environmental effects, and economic results. The projects encompassed seven different categories of agitation dredging equipment and several combinations of physical environment and sediment char­ acteristics. The information gathered from these projects is used to develop ___________ ___________________,_____ (CroUaugfll— DD 1 1473 EDITION OF t MOV 65 IS OBSOLETE ----------Unrl assi fled----—-— — S ECURITY CLASSIFICATION OF THIS PAGE (When Data Entered) Unclassified SECURITY CLASSIFICATION OF THIS PAGEfWTian Data Entered)_________________ 20. ABSTRACT (Continued). a number of general and specific conclusions about agitation dredging and the types of applications for which it is best suited. Several categories of agi­ tation dredging equipment are selected as having the most technical potential. The author recommends that existing agitation dredging technology be improved and standardized and that a comprehensive approach be developed for planning and conducting agitation dredging. Unclassified SECURITY CLASSIFICATION OF THIS PAGEfWfien Data Entered) PREFACE Investigations described in this report were accomplished under the auspices of the New Dredging Concepts project using funds authorized by the Office, Chief of Engineers (OCE), US Army, through the Improvement of Opera­ tion and Maintenance Techniques (IOMT) research program. Messrs. James L. Gottesman (OCE) and Charles Hummer (Water Resource Support Center) are Tech­ nical Monitors of the IOMT research program. This study was conducted in the Hydraulics Laboratory of the US Army Engineer Waterways Experiment Station (WES) under the general supervision of Messers. H. B. Simmons, Chief of the Hydraulics Laboratory; F. A. Herrmann, Jr., Assistant Chief of the Hydraulics Laboratory; R. A. Sager, Chief of the Estuaries Division; and E. C. McNair, Jr., Chief of the Sedimentation Branch. Mr. J. C. Roberge, former Research Hydraulic Engineer, Estuaries Divi­ sion, supervised WES activities in the Harbour Town Marina experiment and gathered much of the information used in this report. Mr. T. W. Richardson, Research Hydraulic Engineer, Estuaries Division (presently Chief of the Coastal Structures and Evaluation Branch, Coastal Engineering Research Center), ana­ lyzed the information and wrote this report. Commanders and Directors of WES during this investigation and the prepa­ ration and publication of this report were COL Nelson P. Conover, CE, and COL Tilford C. Creel, CE. Technical Director was Mr. F. R. Brown. 1 CONTENTS Page PREFACE . ...................... ................................. 1 CONVERSION FACTORS, US CUSTOMARY TO METRIC (SI) UNITS OF MEASUREMENT.......... ............... ............... .............. 3 PART I : INTRODUCTION.......... .................................... 4 D e f i n i t i o n ............................ 4 Objectives .................................................... 5 A p p r o a c h .................................. 5 PART II: FEASIBILITY ...................................... 8 Technical.......... 8 Environmental .................................................. 21 E c o n o m i c ...................................................... 24 PART III: S U M M A R Y ........................ 30 Conclusions.......................................... 30 Recommendations.............. 31 R E F E R E N C E S .......... 34 APPENDIX A: EXAMPLE AGITATION DREDGING PROJECTS AND EXPERIMENTS . A1 Eastham Channel............ .................................. A1 Harbour Town Marina .................. A2 Delaware Estuary . .................................. A10 Chinook Channel.............. A16 Missouri R i v e r ............................................ A21 Pacific Northwest .............................................. A26 Tillamook B a y .......................... A33 Savannah Ha r b o r ...................... ..................... .. A39 Grays H a r b o r .................................................. A52 Mare Island Naval Shipyard .................................... A60 Propeller Jet Erosion ........................................... A82 People’s Republic of China .................................... A84 Louisiana Gulf C o a s t ............ A86 Mare Island S t r a i t ........................ ................. A98 APPENDIX B: DUSTPAN AND SHALLOW-DRAFT SIDECASTER DREDGES ............ B1 Dustpan Dredges...................................... B1 Shallow-Draft Sidecaster Dredges ............................... B2 2 CONVERSION FACTORS, US CUSTOMARY TO METRIC (SI) UNITS OF MEASUREMENT US customary units of measurement used in this report can be converted to metric (SI) units as follows: ___________Multiply___________ By ________To Obtain________ cubic feet per minute 0.02831685 cubic metres per minute cubic feet per second 28.32 litres per second cubic yards 0.7645549 cubic metres feet 0.3048 metres feet per second 0.3048 metres per second gallons per minute 0.06308 litres per second horespower 0.7457 kilowatts inches 25.4 millimetres knots 1.825 kilometres per hour miles (US statute) 1.609 kilometres million gallons per day 43.8056 litres per second pounds (force) per square foot 47.8803 pascals pounds (force) per square inch 6894.757 pascals pounds (mass) 0.4535924 kilograms pounds (mass) per cubic foot 16.01846 kilograms per cubic metre square feet 0.09290 square metres square yards 0.8361 square metres tons (2,000 lb, mass) 907.1847 kilograms 3 AGITATION DREDGING: LESSONS AND GUIDELINES FROM PAST PROJECTS PART I : INTRODUCTION Definition 1. ’’Agitation dredging” is a term that is partly self-descriptive. Many persons will concur on a general meaning but will have trouble arriving at an exact definition. Dredging literature is of little help in this regard as even the textbooks (Huston 1970; Cooper 1975; Herbich 1975) discuss agita­ tion dredging historically but offer no definitions. The Office, Chief of Engineers (1953) defines hopper dredge agitation as ”a process which inten­ tionally discharges overboard large quantities of dredged material with the objective in view that a major portion will be transported and permanently deposited outside the channel limits by tidal, river, or littoral currents.” This single purpose definition alludes to the two distinct phases of agitation dredging which most writers agree must be present: (a) suspension or resuspen­ sion of bottom material by some type of equipment and (b) transport of the suspended material by currents. These two phases in turn suggest the follow­ ing general definition of agitation dredging: The removal of bottom material from a selected area by using equipment to raise it temporarily in the water column and currents to carry it away. 2. This definition touches