WD, at Cea. or Kea Chr Leole, Ree j HEU: =f? Fy : TOBE ~ REPAIR, EVALUATION, MAINTENANCE, AND REHABILITATION RESEARCH PROGRAM US Army Corps of Engineers TECHNICAL REPORT REMR-CO-1 STABILITY OF RUBBLE-MOUND BREAKWATER AND JETTY TOES; SURVEY OF FIELD EXPERIENCE by Dennis G. Markle Coastal Engineering Research Center DEPARTMENT OF THE ARMY Waterways Experiment Station, Corps of Engineers PO Box 631, Vicksburg, Mississippi 39180-0631 December 1986 Final Report Approved For Public Release; Distribution Unlimited Prepared for DEPARTMENT OF THE ARMY US Army Corps of Engineers Washington, DC 20314-1000 Under Civil Works Research Work Unit 32278 The following two letters used as part of the number designating technical reports of research published under the Repair, Evaluation, Maintenance, and Rehabilitation (REMR) Research Program identify the problem area under which the report was prepared: pe Problem=Afeqeaees ——_—Problem Area CS _ Concrete and Steel Structures EM Electrical and Mechanical GT Geotechnical El Environmental Impacts HY Hydraulics OM Operations Management CO Coastal For example, Technical Report REMR-CS-1 is the first report published under the Concrete and Steel Structures problem area. 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. COVER PHOTOS: TOP—Field Research Facility, Duck, North Carolina. BOTTOM—One layer of 7.5-ton tribars used on 8- to 12-ton toe buttressing stone. Tribar and concrete ribcap rehabilitation of a portion of the Hilo Breakwater, Hilo Harbor, Hawaii. REPORT DOCUMENTATION PAGE Ta, REPORT SECURITY CLASSIFICATION 1b. RESTRICTIVE MARKINGS Unclassified 2a. SECURITY CLASSIFICATION AUTHORITY 3. DISTRIBUTION / AVAILABILITY OF REPORT Approved for public release; distribution 2b. DECLASSIFICATION / DOWNGRADING SCHEDULE unlimited 4. PERFORMING ORGANIZATION REPORT NUMBER(S) 5. MONITORING ORGANIZATION REPORT NUMBER(S) Technical Report REMR-CO-1 6a. NAME OF PERFORMING ORGANIZATION 6b. OFFICE SYMBOL 7a. NAME OF MONITORING ORGANIZATION USAEWES, Coastal (if applicable) Engineering Research Center WESCV 6c. ADDRESS (City, State, and ZIP Code) 7b. ADDRESS (City, State, and ZIP Code) PO Box 631 Vicksburg, MS 39180-0631 8a. NAME OF FUNDING / SPONSORING &b. OFFICE SYMBOL 9. PROCUREMENT INSTRUMENT IDENTIFICATION NUMBER ORGANIZATION (if applicable) US Army Corps of Engineers &c. ADDRESS (City, State, and ZIP Code) 10. SOURCE OF FUNDING NUMBERS a ce ELEMENT NO. } NO. NO. ACCESSION NO. Washington, DC 20314-1000 32278 11. TITLE (include Security Classification) Stability of Rubble-Mound Breakwater and Jetty Toes; Survey of Field Experience 12. PERSONAL AUTHOR(S) Markle, Dennis G. 13a. TYPE OF REPORT 13b. TIME COVERED 14. DATE OF REPORT (Year, Month, Day) 5. PAGE COUNT Final report FROM Feb 84 TOOct 85 December 1986 82 16. SUPPLEMENTARY NOTATION Available from National Technical Information Service, 5285 Port Royal Road, Springfield, VA 22161. 17. COSATI CODES 18. SUBJECT TERMS (Continue on reverse if necessary and identify by block number) SUB-GROUP Armor units Rubble mound Wave stability (a a a a os yes Toe scour Jetties Water waves 19. ABSTRACT (Continue on reverse if necessary and identify by block number) The purpose of this survey of field experience is to present an overview of the coastal rubble-mound breakwaters and jetties built and/or maintained by the US Army Corps of Engineers that have or have had stability problems related to structure toes. Exten- sive discussions with US Army Corps of Engineers division and district personnel, along with review of district office files, revealed that rubble-mound toe stability is a major repair and rehabilitation problem that can be divided into two major design categories: (a) design of buttressing stone placed at the toe of an armor slope to prevent downslope slippage of primary armor, and (b) design of toe berm armor size and geometry that will be stable for incident wave and flow conditions and will prevent, or at least slow down, scour and undermining of a structure's toe. No firm guidance presently exists to aid Corps personnel with these two design problems, and most design work is carried out using (Continued) 20. DISTRIBUTION / AVAILABILITY OF ABSTRACT 21. ABSTRACT SECURITY CLASSIFICATION GJ UNCLASSIFIEDUNLIMITED (J) same as RPT. Cloric users | Unclassified 22a. NAME OF RESPONSIBLE INDIVIOUAL 22b. TELEPHONE (Include Area Code) | 22c. OFFICE SYMBOL DD FORM 1473, 84 MAR 83 APR edition may be used until exhausted. SECURITY CLASSIFICATION OF THIS PAGE All other editions are obsolete. incarcerated Unclassified SECURITY CLASSIFICATION OF THIS PAGE 19. ABSTRACT (Continued). limited local field experience on past successes and failures. Design guidance in this area is urgently needed and will be addressed through the use of coastal hydraulic model tests authorized and funded under the Repair, Evaluation, Maintenance, and Rehabilitation Research Program Work Unit titled "Rehabilitation of Rubble-Mound Structure Toes." field survey was conducted under authority of this same work unit. This n¢l ifi SECURITY CLASSIFICATION OF THIS PAGE PREFACE Authority to carry out this survey was granted the US Army Engineer Waterways Experiment Station (WES) Coastal Engineering Research Center (CERC) by the Office, Chief of Engineers (OCE), US Army Corps of Engineers, under the Repair, Evaluation, Maintenance, and Rehabilitation (REMR) Research Program Civil Works Research Work Unit 32278, “Rehabilitation of Rubble-Mound Struc- ture Toes." The survey of field experience, which fulfills one milestone of this work unit, was conducted under the general direction of Messrs. John R. Mikel and Bruce L. McCartney and Dr. Tony C. Liu, REMR Overview Committee, OCE; Mr. Jesse A. Pfeiffer, Jr., Directorate of Research and Development, OCE; members of the REMR Field Review Group; Mr. John H. Lockhart, REMR Problem Area Monitor, OCE; and Mr. William F. McCleese, REMR Program Manager, WES. The survey was carried out by personnel of CERC, WES, under general super- vision of Dr. James R. Houston, Chief, CERC, and Mr. Charles C. Calhoun, Jr., Assistant Chief, CERC; and under direct supervision of Messrs. C. E. Chatham, Chief, Wave Dynamics Division, and D. D. Davidson, Chief, Wave Research Branch and REMR Coastal Problem Area Leader. Visitations to the US Army Corps of Engineers division and district offices to acquire survey data were made by Messrs. Dennis G. Markle and Robert D. Carver, Research Hydraulic Engineers; Mr. John P. Ahrens, Research Oceanographer; Messrs. Peter J. Grace, R. Clay Baumgartner, and Frank E. Sargent, Hydraulic Engineers; Messrs. Willie G. Dubose and Maury S. Taylor, Engineering Technicians; Mr. John M. Heggins, Computer Assistant; and Mrs. Lynette W. O'Neal, Engineering Aide, during the period February 1984 through October 1985. Review of the field experience data and preparation of this report were carried out by Mr. Markle. This report was edited by Ms. Shirley A. J. Hanshaw, Information Products Division, Information Technology Laboratory. CERC would like to thank the personnel of the US Army Corps of Engineers division and district offices contacted and visited during this survey. The timely and thorough completion of this study would not have been possible without the outstanding assistance and information provided by these individuals. Commander and Director of WES during publication of this report was COL Dwayne G. Lee, CE. Technical Director was Dr. Robert W. Whalin. CONTENTS NIBWNCIISG Gooodo00GDDD0DU0D000000E FOOD ODOUDDOD GOD DDODODDODDOODDODDDDDONDDN 1 CONVERSION FACTORS, NON-SI TO SI (METRIC) UNDELS) (OF) MEASUREMENT yoe ojeleielse/eie soo0av0D0DDDDDDDDDNNDN eNehelMekeNonTekclenencisionone PART I: DPN TROD U ClenkONrerleteieNeknelekckonekoiclonele do6000000000600006000 SOCIO Beaveliewcowinels o 6G0 00 00D DD0DDD ODD 00DD D0 DDD OD GDOO00D000000 00000000000 Authority, Purpose, and Approach........ 9000000000000000000000000 PART II: FIELD EXPERIENCE. . 0... ccc cece cc ccc cer c cer er ccc crensssscsees ReEvestizal@ Oeaeim IDINALATOING 5666000000 b ODDO 0ODDODODOD DODD DOD000GAD00000 Nowa Raewitsle Wak valeloing oooon 00000 0OD DOD DD DDDDDODDODDDDDNDDDDNDD0N000 Somtln PRevesiieske IWshylesleyno oo g600000000000000000000000000000000000000 Someiwastearan Daiwalsatoinoooq0000000000000000000000000 GHUOO OH OCO000000 D5) Lower Mississippi Valley Division........ccccccsccccccccccecs 900 29 Some ‘Nelleyneste rbyalsaleins 66060066000000000000000000000000000000000 29 NomehwAGlant:cMDA VA SHO Metereneteneenolederclelekekehotonelevelohelali Reichel hellelelsteiehellenenetet one 40 New Bozileral Walyalestoine'so000000000000000000000000000000000000000000 42 Noreln Cemeraul Waking doococodsboddobon0dDOd DDD OO D00DDDD00D00D0N000 46 PART TITLE: DISCUSSION. 2.2.2. ecw cece merece vce crceceresessrsecs 5000000 76 PART IV: CONCLUSION oie). <2 esis) ele «cls oele « 66000000G00000000 o9g00d0000000 78 3 4 4 4 6 Summary of Contacts and VisitationsS......cscccccccccccccccrcccoss 6 8 13 25) CONVERSION FACTORS, NON-SI TO SI (METRIC) UNITS OF MEASUREMENT Non-SI units of measurement used in this report can be converted to SI (metric) units as follows: Multiply By To Obtain feet 0.3048 metres miles (US statute) 1.609347 kilometres pounds (force) 4.44822 newtons tons (force) 8896.444 newtons STABILITY OF RUBBLE-MOUND BREAKWATER AND JETTY TOES; SURVEY OF FIELD EXPERIENCE PART I: INTRODUCTION Background 1. Failure of rubble-mound breakwater and jetty toes is a problem whose solution has plagued the majority of the US Army Corps of Engineers (Corps) divisions and districts responsible for designing, constructing, and main- taining these structures. Instability of a rubble-mound structure's toe directly impacts on the primary armor stability and overall performance of a structure. In most instances, instability (failure) of a structure's toe does not become evident until it has resulted in damage to the primary armor which has progressed up to or above the still-water level (swl). This observable damage can range from a minor slumping or reorientation of a few armor units around the swl to the total disappearance of large numbers of armor units. Left unattended, this type of damage could propagate upslope at a rate depen- dent upon incident wave conditions and severity of the toe and lower slope armor damage. In many cases, it will result in either localized or widespread failure of the structure. 2. No guidance presently exists for the preparation of adequate repair and/or rehabilitation designs for damaged or failed rubble-mound structure toes. A concentrated effort to better understand the various types of toe stability problems and to develop and document effective repair methods is urgently needed. Through the development of sound design guidance, the need for frequent repair work will be minimized which will result in substantial dollar savings. Authority, Purpose, and Approach 3. Under the Repair, Evaluation, Maintenance, and Rehabilitation (REMR) Research Program, the US Army Engineer Waterways Experiment Station's (WES's) Coastal Engineering Research Center (CERC) has been authorized and funded to carry out a work unit under the Construction, Operation, and Maintenance Research Area titled "Rehabilitation of Rubble-Mound Structure Toes." The prime objective of this work unit is to develop guidelines for repair and/or rehabilitation of rubble-mound structure toes. This will be accomplished through conduct of the following four work phases: a. Through telephone contacts with design, construction, and opera- tions personnel in the Corps' division and district offices it will be determined where structures exist that have, are felt to have, or have had toe-related stability problems. Once this is accomplished, follow-up visits will be made to the division and district offices to gain a better understanding of the problems, and the steps that were taken (if any) to alleviate the prob- lems, and the relative success or failure of the repair or rehabilitation work. Once an overall understanding is gained of the various toe stability problems confronting field designers, they will be categorized according to type. Subsequent to this, general experimental model testing programs will be developed to address the various problem types. The goal of these tests will be to experimentally determine and document improved methodologies through which successful toe repair and rehabilitation work can be designed and carried out. |o c. The experimental model tests (both two- and three-dimensional) will be carried out over a 2-year period. During this time, the scope of the tests will be subject to periodic changes based on continued information obtained and additional understanding gained on the problems confronting field personnel. d. A thorough analysis of the data compiled during the model tests will be carried out in an effort to produce general rubble-mound toe repair, and rehabilitation guidelines and a comprehensive report covering the model tests and presenting the experi- mentally developed guidance will be prepared and published. Item a has been completed and is reported herein. Continued efforts will be made to maintain contact with and to obtain additional information from field personnel faced with rubble-mound toe stability problems. Item b has been completed for the presently available data, and two-dimensional experimental model tests (Item c) have been developed and initiated. A three-dimensional test series (Item c) is being developed based on findings of the two- dimensional tests. As previously stated, Item b and, in turn, Item c are subject to change as more field experience information becomes available. PART II: FIELD EXPERIENCE Summary of Contacts and Visitations 4. During the period February 1984 to October 1985, 9 division and 21 district offices (Table 1) of the Corps were contacted by telephone in order to determine whether any rubble-mound toe stability problems presently exist or have existed on the coastal structures under the jurisdiction of the various offices. The points of contact at each district office were those recommended by the REMR Field Review Group members from the district's division office. Of the 21 districts contacted, 12 responded positively regarding existing or past toe stability problems. 5. Prior to a district office visit, a copy of the district's project index maps was obtained in order to become familiar with the authorized coastal structures and their current status. During the planning stages for a district visit, it was requested through the district point of contact that upon arrival at the district office a meeting be held so that a detailed explanation of the purposes of the visit could be given and so that an over- view of the district's coastal structures and the various problems and repair histories related to them could be obtained. Notably, the Wave Research Branch (WRB) of CERC is funded for three REMR work units other than the one being addressed herein, namely, (a) "Use of Dissimilar Armor for Repair and Rehabilitation of Rubble-Mound Structures," (b) "Repair of Localized Damage to Rubble-Mound Structures," and (c) "Techniques of Reducing Wave Runup and Over- topping on Coastal Structures." In addition to these, the WRB has been autho— rized under the Coastal Program's Research and Development Work Unit titled "Breakwater Stability" to write case histories on all breakwaters and jetties built and/or maintained by the Corps of Engineers. All of these work units require the gathering of field data; and for this reason when WRB personnel visited a district office, data were gathered, when available, for each of the work units. It was requested that, where possible, the meeting be attended by district representatives from planning, design, engineering, construction, and operations. In this way, it was assumed that the data obtained would reflect all areas of concern relative to a district's coastal structures. Table 1 Divisions and Districts Contacted Method of Contact District/Division Telephone ~=Visitation Problems Honolulu/POD* Yes Yes Yes Alaska/NPD Yes Yes No Seattle/NPD Yes Yes Yes Portland/NPD Yes Yes Yes San Francisco/SPD Yes Yes Yes Los Angeles/SPD Yes Yes No Galveston/SWD Yes Yes Yes New Orleans/LMVD Yes Yes Yes Mobile/SAD Yes Yes Yes Jacksonville/SAD Yes Yes No Savannah/SAD Yes Yes No Charleston/SAD Yes Yes No Wilmington/SAD Yes Yes Yes Norfolk/NAD Yes Yes No Baltimore/NAD Yes Yes Yes Philadelphia/NAD Yes Yes Yes New York/NAD Yes Yes No /NED Yes Yes Yes Buf falo/NCD Yes Yes No Detroit/NCD Yes Yes Yes Chicago/NCD Yes Yes No * POD - Pacific Ocean Division; NPD - North Pacific Division; SPD - South Pacific Division; SWD - Southwestern Division; LMVD - Lower Mississippi Valley Division; SAD - South Atlantic Division; NAD - North Atlantic Divi- sion; NED - New England Division; NCD - North Central Division. 6. Following the entrance meeting, all available information on the district's coastal structures (design memorandums, plans and specifications texts and drawings, reconnaissance reports, photographs, etc.) were retrieved from the district's files and duplicated. The data were then taken back to CERC for scrutiny by the principal investigators assigned to the various work units. 7. Where representative structures were near the district offices, site visits were made to gain a better understanding of the type of construc- tion used on the district's structure. During these site visits, photographs were taken to document the above-water conditions of the structures. Because of time constraints and remoteness of the structures, site visits were not possible at some of the district offices. 8. Prior to departure from the district office, an exit meeting was held for WRB personnel to summarize their findings to ensure that no miscon- ceptions were drawn from the data gathered. Where possible, the same personnel attended the exit meeting as had attended the entrance meeting. 9. In some instances, the quantity of data contained in the district's files was so massive that time was not sufficient for WRB personnel to dupli- cate the data during the time allotted for the visit. When this situation occurred, a request was made for the district to provide personnel, when and where available, to duplicate data and send it to CERC. In some instances, it was determined that an additional visit to a particular district by WRB personnel was needed to adequately review the available data. Pacific Ocean Division 10. The Honolulu District of POD has three breakwaters which have problems and/or design questions that are related to toe stability. Two of the structures, Nawiliwili and Hilo, had a related problem. The head and adjacent 500 ft* of breakwater trunk at Nawiliwili Harbor, Kauai, Hawaii (Figure 1), were rehabilitated in 1959 using 17.8-ton tribars. Model * A table of factors for converting non-SI units of measurement to SI (metric) units is presented on page 3. VICINITY MAP B HARBOR 10-TON STONE PACIFIC @HANALE! 1/2-TON STONE 1.5 MLLW EL 0.0° 1/2-TON STONE: -12.0° (QUARRYRUN) ; 1/2-TON STONE @WAIMEA rere NAWILIWILI) BREAKWATER HARBOR TYPICAL SECTION A-A “NAWILIWILI BULK SUGAR PLANT-»S\\, PIER SHEDS - <9 2 oS Fetes ee REVETTED FILL AREA. . | aa BREAKWATER B SMALL B 4 ; OAT & % ARBOR H CONCRETE POST~: a8 CONCRETE CAP HARBOR _MELWEL 0.0" BREAKWATER TYPICAL SECTION B-B Figure 1. Nawiliwili Harbor Breakwater, Kauai, Hawaii tests*, conducted at WES in 1958, revealed that two layers of randomly placed tribars on the head and one layer of uniformly placed tribars on the trunk were the best methods of rehabilitating the storm damaged structure. A survey in 1975 revealed extensive tribar breakage, and later it was found that the toe buttressing stone recommended for placement at the toe of the one layer of uniformly placed tribars had not been incorporated into the construction specifications. It was surmised that in the absence of these buttressing stones the tribar toe slid on the hard bottom which resulted in an en masse slippage and breakage of several tribars. This area was rehabilitated with two layers of randomly placed 11l-ton dolosse onslope and through the use of special placement of the toe dolosse. This latter work was also model-tested at WES.** 11. A repair similar in design to that used on Nawiliwili in 1959 was completed on the Hilo Harbor Breakwater, Hawaii, Hawaii (Figure 2), in 1981. One layer of uniformly placed 7.5-ton tribars was placed on the sea-side slope of the breakwater between sta 11+00 and sta 20+00. Based on knowledge gained through the failure of the Nawiliwili tribar section, a row of 8- to 12-ton buttressing stone was incorporated into the toe repair. No design guidance is presently available to aid in sizing the buttressing stone for an incident wave environment, and no model tests were conducted. For this reason, close monitoring of the repair work should be carried out after storm events. Thus, POD and the Corps as a whole will gain from prototype experience which can be used to complement the data acquired during the experimental model tests on toe buttressing stone design proposed to be carried out under this work unit. 12. Haleiwa Harbor, located on the north side of the Island of Oahu, Hawaii (Figure 3), was modified in 1975 by the addition of a revetted mole and two stub breakwaters. Subsequent to this time, repairs were required on the 80-ft breakwater due to a slippage failure of the primary armor stone. Close inspection of the structure revealed that the bedding and berm had been * R. A. Jackson, R. Y. Hudson, and J. G. Housley. 1960 (Feb). "Design for Rubble-Mound Breakwater Repairs, Nawiliwili Harbor, Nawiliwili, Hawaii," Miscellaneous Paper No. 2-377, US Army Engineer Waterways Experiment Station, Vicksburg, Miss. ** D. D. Davidson. 1978 (Jan). "Stability Tests of Nawiliwili Breakwater Repair," Miscellaneous Paper H-78-4, US Army Engineer Waterways Experi- ment Station, Vicksburg, Miss. 10 8 TON STONE SEA SIDE MLLW_EL. 0.0 Se BRE) EL. -12.0 2 TON STONE BREAKWATER (COMPLETED) TYPICAL SECTION A-A LOCATION MAP ISLAND OF HAWAIL : ea TES. oo E BREAKWATER 10,080 FT LONG KUHIO. BAY | Coa o WAILUKU RIVER f \ S <) Be \= Whe ' | WAIAKEA a HARBOR BASIN A 2,300 FT. LONG 1,400 FT. WIDE PROJECT DEPTH 35 FT CONC RIBS DOWELED INTO CREST STONE OCEAN SIDE ONE TRIBAR THICK 7.68 TON TRIBARS 10% —~ SCALE \N FEET 2000 1 TO 2 TON UMNDERLAVER OME ROW OF & TO i2 TOM ARMOR STONES ALONG BREAKWATER TOE TRIBARS REPAIR SECTION B-B STA 11400 TO STA 20+00 Figure 2. Hilo Harbor Breakwater, Hawaii, Hawaii iil HALEIWA 2 LAYER OF 2 TO 4 HARBOR TON STONES EXIST GROUND REVETTED MOLE 125° BEDDING STONES TYPICAL SECTION A-A SPALLS TO S0# LOCATION MAP ISLANO OF OAHU O8466 SCALE IN MILES ENTRANCE CHANNEL 740 FEET LONG 12 FEET DEEP 100/120 FT WIDE AVE ABSORBER \: 140 FEET LONG EXISTING ENTRANCE CHANNEL BOAT SLIPS 200 SCALE IN FEET QUARRY : 1975 DESIGN 10, RUN 2# SS SE TO 50# BUDS 2 LAYERS REVO 1T TO 2T STONE 2 LAYERS 100# TO 400# STONE 9 &LO EXISTING BOTTOM VARIES BOTTOM VARIES 2#TO50#STONE ‘BEDDING TYPICAL SECTION TYPICAL SECTION 110 BREAKWATER —_ 80’ BREAKWATER Figure 3. Haleiwa Harbor Breakwaters, Oahu, Hawaii 12 omitted from the construction. Localized scour had undermined the armor stone toe and resulted in the slippage failure. The structure was repaired by ex- cavating around the perimeter of the structure down to firm bottom and over- laying the structure head with an additional layer of 1- to 2- ton armor stone which extended down to the toe. This repair was feasible due to the shallow depth of the sand in the area of the west breakwater. No stability problems have been observed since the repair was completed. North Pacific Division Seattle District 13. The south jetty at the entrance to Grays Harbor, Washington (Fig- ure 4), has sustained severe scour on the channel side toe. The outer 5,600 ft of the jetty are presently below mean lower low water (mllw). It is not known if the toe scour is the cause, or a portion of the cause, of the present deteriorated condition of the jetty. Presently, no repair work is planned for the Grays Harbor Jetties. 14. As of August 1985 plans were being developed for the repair of the rubble-mound breakwaters at Edmonds Harbor, Washington (Figure 5). It is not definitely known that toe stability was a cause of some of the existing damage, but it is thought to be a probable cause. The bottom drops off on a 1V:2H slope to a deep depth just out from the toe of the breakwaters. There is some thought that this deep water adjacent to the structure, which allows large amounts of wave energy to reach the structure, could be initiating toe stability problems. No firm decisions had been made on the repair design when this report was being prepared. Portland District 15. The north jetties at the mouth of the Columbia River, Tillamook Bay, Yaquina Bay, Siuslaw River, Coos Bay, and Rogue River, the south jetties at Nehalem Bay and Umpqua River, both jetties at the Chetco River, and Jetty "A" at the mouth of the Columbia River have all shown toe stability problems. The problems at these 11 sites (Figures 6-14) are the result of one or a combination of the following: (a) ebb and/or flood flows training on the channel side of the jetties which undermine the jetty toes, displace the toe berm stone or a combination of both, (b) wave- and flow-induced displacement of toe berm armor and foundation scouring and undermining at the jetty heads, 13 OCEAN v & 6 x a NORTH JETTY SCALE IN FEET so evETTY VARIES 5) ' ROCK BLANKET MIN. THICKNESS 3° SOUTH JETTY SCALE IN FEET 5 20° 0 0" 190) TYPICAL_SECTIONS (LOOKING WEST) SURFACE FAN SHORE == Z oc 2 > § “ ae - S . er a S » GRAYS” 1975 JETTY “HA RBOR REHABILITATION. % S SUBMERGED JETTY ~ if f = \,200) w ~ S NX Q ‘Potht Chehalis Westport]. / SUBMERGED JETTY ans Rivet BAR CHANNEL fol 600° WIDE 966 ETTY BAY CITY CHANNEL 30’ DEEP REMABIEITATION 100' WIDE, 14’ DEEP VICINITY MAP SCALE IN FEET SCALE IN MILES 5000 10.000 Figure 4. Grays Harbor Jetties, Washington 14 uoj}3upzYysemM *‘Sieqemyeeig AOqieyY Spuowpy °¢ eAnsTy oz % os Oo 1234 MI NYS 1334 MI aNW>S YILVMAVIIG Jd BIVWIL ‘NOMDIS TWHdAL WILVMAVIIG NIVW NOIMLDIS IVDIdAL Twit) _ SMuvA 1a ARES S21UVA 13 oniogaee QNnOED aaeEnisiaNn ANNOSD IanivN yi c } sativa’ 7 > i z ABINWIG 19AVED WDIHL OL AINNIEBIZAYEO TEL ~ ‘ Silvas AuuYNO 410 LDINVIG HHH Ot ~32v4 wiv oO} So) ul 0/095 dVW NOILV9O1 VIdWATO$# Yeowersian die301) NISV@ ONIUOOR SQNOWG3 ; ; (peujoiujow Aj}020)) y Santer [pevioiwiow djjosepe, 31L1vas UaLVMNVaNS 371d YaEHIL ok wanec en 4 ROTH CE 1S NOlAva “W’NNVHD =~ JNVULNI ~ = G 3 a) mS) (Pewiojuiow djjosepe)) BRLVMNVINE Fld YIGWiL a WAY SGNOWQ3 Foye 4134343 4Y (paujojujow \10201) Y3LVANV3aNe~ y Y3ld ONIHSI4 9178Nd 15 uo8et9 ‘setj3ef AAATY ePTQUNTOD Fo yANoW *g eANnsTy Ct Se 1334 Mi_3TWS SNOILOSS IWOIdAL ALL3a¢e HLNOS ALL3f HLYON 3-4 aa OL) WijOvoRY 70 vsb27 (0104 perowny oy woysed eared trai cg C1 eoyiaf Jo pee iro +) ebooge p ywod eg 'BL0N ff ie a, a L, VIUYOLSY st (2778), 602 — MYde MIVA “72 147A .010/~ YAS MIV “79 “T1¥0H say crqowon -N22340 NOL ONTStT— + ONIHS VM o mato. 499f0ud 20130" tala 5 ‘ jesopog £4 porisoyiny Jpaig yo ie) weassedn: @ SNOIL93S TWOIdAL a, ALLIS Qu07 eo G2 Auer won es 16 MEAD OF NAVIGATION MORIZ. CL. - 92° VERT. CL - 20" VICINITY MAP ° Rox L LAM OO K 2 wicGhway ELEVATION IN FEET 16 i] To 10 0 10 DISTANCE IN FEET DISTANCE IN FEET SECTION A-A SECTION B-B NORTH JETTY SECTIONS 3 Beach 10 10. DISTANCE IN FEET EE a; | @SECTIONLC SCs SECTION D-D Federal Project SOUTH JETTY SECTIONS (EXISTING CONDITIONS SHOWN) Nehalem Base Point of mileoge is about 530 feet shoreward from the outer end of the Jet ties. OREGON SCALE IN FEET 2090 1500 o 1600 3000 Wheeler fo Tillamook Figure 7. Nehalem Bay Jetties, Oregon 17 Twin Rocks Sr) 4 SECTION A-A 18 Feet Deep, No Width Specified | 35° Sonica ‘eet Wide. Turni: Basin 500 Feet Wide VICINITY MAP pode im Bee ° 190 Mooring Basin @ Approach i2 Ft Deep. * XS g ==“ MORIZ. CL. - 937 a / VERT. cL. -HI" South Jetty ariba 5 4 8,000 Feel Long 4 =~ =~ tf Miami R. a Oi Upstream Limit Federal Project SECTION B-B LL AM OO K GS oO WIN mw ve 123°50" Boulder Point Rock Point : * Dick Point : i MORIZ, CL. - 15" 1 VERT. cL. - 28° Note: ee Bose Point of mileoge is in za line with shore line north of ir Jetty ond is 4500 feet seaward ‘ (olong range tine) from U.S. Highway No./0/. \ fa) ‘\0ceanside es are. \ PREF 68 ow TILLAMOO é { TRUE BORTH MORIZ. CL. - OS" VERT. Ch. - 14.5" COR fmol ia een oie oe ae ras =a B moRIE. CL. - 70" ee aE ee Ee ae ae 20 ° Lr) @ TYPICAL DIKE SECTION SCALE IN FEET 8000 as] Dara within boxes pertain to Authorized Project Figure 8. Tillamook Bay Jetties, Oregon 18 ° OurmPia LINCOLN COUNTY Channel 30 feet deep, 300 feet wide from end of Entrance Channel to McLean Pt, VICINITY MAP. TN MIL Dato within boxes pertain to Authorized Project. Q Base pointofmileoge is one 8°X 20" Sheeting mile downstream trom U.S. Highway 101 Bridge. MOORING lighway 101 Bridge. BASIN TYPICAL BREAKWATER SECTION Naa) EY SET) AB SCALE IN FEET TYPICAL SECTIONS 10 9 i} SCALE IN FEET SCALE IN FEET 500 1000 Figure 9. Yaquina Bay and Harbor Breakwater and Jetties, Oregon 19 igs EL. Varies ¢ Stone prior to : a Stone prior to Mae Waeeaiinn TYPICAL NORTH JETTY SECTION rehabilitation TYPICAL SOUTH JETTY SECTION 25 ° 25 50 25 ° 25 50 NORTH JETTY EXISTING ENTRANCE CHANNEL 7790 FEET 18 FT. DEEP BY SOO FT. WIDE FROM DEEP WATER TOA POINT 1,500 FT. INSIDE OUTER END OF EXISTING NORTH JETTY. 600' FOOT NORTH JETTY EXTENSION UNCONSTRUCTED SOUTH JETTY 4200 FEET EXISTING CHANNEL 200 FT. WIDE BY IGFT. DEEP TO FLORENCE STONE GROINS (5) eG CUSHMAN Va MORIZ. CL. -110" VERT. CL.-NO LiMiT CHANNEL 2 FT. DEEP uy BY ISOFT. WIDE PILE DIKE c FLORENCE TO Mi. 16.5 GROINS (6) GCENADE ae EXISTING TURNING BASIN I6 FT. DEEP BY 400FT. WIDE BY 600 FT. LONG VICINITY MAP. SCALE IN MILES Figure 10. Siuslaw River Jetties, Oregon 20 uose1Q ‘setzjer AeaaTy enbdug -*{{ esan3Tq meus oe 3 i ss 1334 m1 a0v38 : : pias Strats v atts ade aeons Soo C0cy COOK C00? CON OC) ALLaf ONINIVYL S0110{ 40 pue 10170 40 piomesoys 120) T*o x 4334 Mi Jos 3-3 NOlloas 006'2 inogo CE TIT) re 9 faig ce ALLA? ONINIVEL peroyiny 0} voised serog ayia jog L—] ~ 4-4 NOILOaS ” svejpu0g N 826] s8nOny jo so eu/7 sn0IS pesowyjsz. 145/42 0u/7 punos. 9 Uy H Ava ua1S3HONIM 77 —— > 6 ow AS) MT TW aa} > 9) 4 b CAD ILA LE) i ° nN are wale ‘\ Rien % euols ¥ 8 80/9 aii es 4 i (heir i > — . YFAVT UILTIF a) \ NIW L334 & GNNOd 005-Sb YFAVT ONIGOIE NIW 13348 NVA90 2N0LS NOL 9-E ¥3Av7 YOWYY 0z Ov 301 SLVWIXOUddY z0'01+99=£17 Ne ‘NZ :NOILOSS IVOIdAL 006 ogz 092 Ove O%% OOZ OBt O9t OPI OZ! O0t og 09 Op 0% —————_—__—__—————— 09- TivVLag GVaAH (SH3AV1 Z DAV) NIW 19348 INOLS NOL 9-E 43AV7 HOWE v.08 "ol ‘Obl | ee YL) JONVYLNS YOSYVH S Yy) —— NT NOILOAS TWOIdAL 08% 092 ObZ ozz O0Z OBL O91 Ori OZ! COL OB 09 OF 0% SaIBYA 3SS0100 NOL-2> NZ ov- NL (M71W .Lh- 3N4OWd Al ae a ONILSIXI re 4 |3 > NIW L334 E | Ss 02 6 Ws 3 HONIOL-zZ/1 |} WG VW YOSYVH IY IIe waAv7HILTI9 |B 7) HLITONOW a ho JONVYULNA YO 3.18 g NIW 1334+ |2 me Ye Ke aNnnod 005-56 |= oz xoudd G we Ss ¥JAV7 ONIOGIE 2 ----f£--— m a4 ie] im 01+89 VLS Altar jod 09- pl+2Z VL ae vn NOIVI: y3LVMxvIua JO SHINYA ee ay FOL ONILSIXI we 34018 a> < (SU3AV1E DAV) = (MTIW.L1) Hdd¥ ——508570q NOL tel O- ag NIWL334 6, ~~ _ adoud = vaevuivddd x eo HONI OL - 2/t ~. INILSIXI: G usAv7uaits| & i She a 3LVWIXOUddV NINLIII~ | (92 G Uh F GNNOd 009-58 | & 47 4 waav7oniaaza —\R.d Be 8 NV300 x NIN 19348 m F ‘2 4NOLS NOL 9-E 9 5 ; 790°" 2 W3AV7 HONEY. | 2 1p ¥,001 (091 NG ‘ JONVYLNA YOSYVH ) NB NE NL No N S 2, S861 “1atedei AI3aPr YANOS Keg aprToquny °/] aan38tq 00+68 VS O1 00+%8 VIS NOILI510Ud SOL =NOILOSS IWOIdAL 08% 092 Oz Oz% 00 OB! 091 Obi Oz! 001 o8 09 OF oz oO 09- Ov- (M77W) .L1- XO¥ddv NIW T3396 |< MTA) k= x08 Oz HONI OL - 2/t PSs YIAVT ILI SsSs5 LI70NOW ~ O NIW L335 Sq Ladle INNOd 005-s¢ Ss i 49Av7 NIGGA ‘eeocléa| NIW L374 8 INOLS NOL 9-€ Nv390 YIAV7 YOWHY : O41 aI —— Sé SL : NOILDAS TWOIdAL 082 09% Op 02% oOz OB! O91 OF1 OZ! 001 of 09 ov oz o A oS NIW 1334 € HONI O1- 2/t YIAVT UIT Cre = (M71W) .£1- XO¥ddY ~ ~~ IMIOUd ONILSIXF 0z- HLITONOW IO dOL (0) / 4 ExT) 3 SYUFIAVTS OAV 3SSO100 NOL Ze NIW L334 > ONNOd 00S-Sb ¥JAV7 ONIGGIE NIW 13358 INOLS NOL 9-E YFAV7 HOWE & NV1d Sv aa ee Sab) vo —— Sa 2 es =: A) 313¥9NOD ey aie so sg & Ds .» NODV38 & 2 SL JONVYLN3 YOSYWH sé $8 B TWVLIG :GV3H os eB g 5 %y, eo Z Nva00 3 5 G,. & \ ; ONCE, 5 WATERWAY. (FOR DETAILS SEE foes SHEET 9-2) CE CEHED TS AUTHORIZED CHANNEL Inside (Bay) 40° x 300° Gulf Approach 42x 450° GRAND LAGOON CHANNEL 8° x 100° "S ST. ANDREWS STATE PARK & WEST. JETTY EXISTING CHANNEL, Inside (Bay) 32 x 300 FOR JETTY DETAILS SEE SHEET 9-/ MEX/1CO PLAN SCALE IN MILES CHAN 38 x Fee D> Wz —— NEL 300 Gulf Approach 32 x 450 : <} PANAMA AUTHORIZED ANCHORAGE AND LOADING BASIN FOR LASH TYPE INTERMODAL CARRIERS - DEPTH 40 A WATSON BAYOU | CHANNEL 10'x 100 ieee [ | BAY HARBOR BEACON BEACH Figure 21. 33 Panama City Harbor Jetties, Florida 19+65N 14+89N COUNT ¥ 10+ 25N ROCK JETTY EXTENSION ST. ANDREWS : BAY Ki STEEL SHEET fj PILING 5 To: ASPHALT ‘ 2+ 30S oe ROCK JETTY EXTENSION ahaa nN STEEL SHEET PILING \ Ween i >, WE wy —— 9+99E N (©) 7T+O4E ) AY s—— ce CA O+00€ G24 <3. +005 0+00 1+ 00N 40s “EAST JETTY Bis PLAN SCALE IN FEET 500 1000 1500 SECTION A-A Cap Stone Riprap Stone i<«—Stee! Sheet Piling SECTION C-C SECTION B-B Figure 22. Details of Panama City Harbor Jetties, Florida 34 as well as stabilize them to the existing armor stone structure. This design proved to be unsuccessful. Scour initiated at the toes of the mats and, as the mats subsided into the scour holes, they pulled the mats and armor stone off the upper slope which resulted in general deterioration of the jetties. Subsequent repairs were carried out by placing a toe berm of 100- to 200-1b stone and, where needed, overlaying the old structure with additional armor stone. 21. Toe scour also has been noted as a problem with the jetties at East Pass Channel and St. George Island, Florida, and Perdido Pass Channel, Alabama (Figures 23-25, respectively). Scour on the channel side of the east jetty at East Pass is so severe that it is thought that portions of the jetty may slide into the channel at any time. In the past, this type of slippage failure has caused severe damage to the west jetty at Panama City. 22. Jetties at St. George Island have suffered cover stone loss result- ing from the undermining action of toe scour. The west jetty at Perdido Pass presently has significant amounts of toe scour on the channel side, and Hurri- cane Frederick produced significant amounts of toe scour on the east jetty. The overall condition of the Perdido Pass jetties was said to be good; there- fore, it is assumed that the toe scour has not caused any obvious damage above the waterline. Wilmington District 23. The 3,650-ft-long rubble-mound north jetty located at Masonboro In- let, North Carolina (Figure 26), was constructed between August 1965 and June 1966. The north jetty required extensive repair on the channel-side toe of the outer rubble-mound structure in 1969 and to the channel-side toe of the inner weir section in 1973. This was prior to construction of the south jetty (14- to 22-ton armor stone) in 1980. It was thought that ebb and flood flows had caused the channel to move adjacent to the north jetty, creating the scour problem. In both repairs, a 2- to 3-layer protection of bedding mate- rial and riprap (25 to 2,000 1b) was used. This toe protection butted against the existing armor stone toe or sheet-pile weir. The berm width varied from 30 to 50 ft. It is thought that this work had limited success because the jetty has not totally deteriorated, but it is presently in need of repair work in several areas. Presently it is unknown whether the deteriorated appearance of the north jetty results from a toe scour problem or from the possibility 35 DESTIN Ee iY MORENO POINT FIXED BRIDGES HOR. CL.78' VERT. CL. 38° SAND DIKE STONE JETTY SECTION 5 WEIR SECTION / DEPOSITION BASIN: 7 OPEN WATER DISPOSAL SITE PLAN SCALE IN FEET 1000 GULF OF DEPTHS ARE IN FEET AND REFER TO MEAN Low water. S/OME JETTY SECTION MEMPHIS T ENN CHaTTANOOGA“ AS Y) Le 7 ' T Columbus. * JeiRMINGHAM Ce RATLANTA ¢ iy PY \ cla € \ | Symmetrico/ obout € MONTGOMERY ¢ Ry = S i ~ Existing ground surface z (Elev vories) ~"yRescacout PROJECT © TYPICAL JETTY SECTION RIVER, ae LA: ) ‘ FLA \C Gul!port BRA CACHIC OLA! . Cees ge mqoce yom" TALLAHASSEE ORLEANS' mw? GULF OF MEXICO VICINITY MA SCALE INMILES so 9 50 100 Florida Figure 23. East Pass Channel Jetties, 36 E N N CHATTANOOGA APALACHICOLA ‘> ‘ é No s Sir 4 ST. GEORGE f me SIP Nec alGereyty 24 ci] s ey CHANNEL 3 WS Ss z . 4 3 =) 10'x 100' TO 200 aS at § MISs li WALA & YAGKSON 3G Meridian AWER ls : MONTGOMERY Py fle Nl s : AGE ya ey > news z N. fines) AZ S \ a | MOBILE = ~-prascacoury ae Dv aver {woae “a, NITY MAP SCALE INMILES ° 50 100 VICI GULF INTRACOASTAL WATERWAY /2°X 125° EASTPOINT CHANNEL 6 x/00 APALACHICOLA AIRPORT ~NSWING BRIDGE S BULKHEAD SHOAL \ MOR.CL Me, CHANNEL 10'x 100", i ——— 1 5 (NOT MAINTAINED) Mee ST VINCENT TWO MILE BREA WATERS | \ ra TWO MILE CHANNEL CLUECINE \\ i SOUND 6x100' CHANNEL fi ee AINNER BAR CHANNEL 10 x 100 awe” (MAINTAINED TO 12'X 125’ UNDER te PROJECT FOR GULF INTRACOASTAL WATERWAY.) =—eRWAY ; a= WATE _-t FIXED BRIDGE «=, ee i 388 =cut a HOR.CL 125° = “s.._ VERT. CL. 50° ST. GEORGE ISLAND CHANNEL 10'x 100' TO 200° TWIN RUBBLE MOUND JETTIES _.” en" os DEPTHS ARE IN FEET AND REFER TO MEAN LOW WATER. MILEAGE ON GULF INTRACOASTAL WATERWAY 1S FROM HARVEY LOCK, NEW ORLEANS, LA PLAN SCALE IN MILES 1 oO U 2 3 aaa TYPICAL JETTY SECTION Figure 24. St. George Island Jetties, Florida 37 N TERRY COVE WALKER ISLAND) PERDIDO BAY STA. 32+00 ong —Q ISLAND a FIXED BRIDGE CLEARAN TO COTTON BAYOU ee HORI VERT. 29° TO PERDIDO BAY HOR. 80 VERT, 35° FLORIDA POINT €@ UNM GULF OF MEXICO PLAN SCALE IN FEET 800 oO 800 1600 SESE TR DEPTHS ARE IN FEET AND REFER TO MEAN LOW WATER. Ca MEMPHIS T(E NUN} CHATTANOOGA CORESTONE CAPSTONE 25 To 2 TONS 8 TO12 TONS, FOUNDATION BLANKET 3 Geen .) \ r MONTGOMERY TYPICAL SECTION THROUGH JETTY « x é 5S N = = $ = psseaaouy t S SCALE IN FEET Yama 10 oO 10 20 Ss )=SE APALACHICOLA RIVER = _ Poromq PROJECT *X" GULF OF MEXICO Figure 25. Perdido Pass Channel Jetties, Alabama 38 aN NORTH 7T90.< > CORE CREEK BRIDGE is SIDE CHANNEL Ca CAROLINA - & BASIN AT Y & JACKSONVILLE SWANSBORO Whe, = a 6] ‘ CHANNELS TO S. aNGe aS JACKSONVILLE & > Z; 2/0 NEW RIVER INLET Ye \ G oe SZ Bocue \PELTIER CREEK oad Ld INLET N = ZA S. WA a2 CHANNEL TO p Bi % BOGUE INLET € ~ hy 0 iG CONNECTING CHANNELS CG MASON BORO INLET a are OSI) LG AND CONNECTING iy SOUTHPORT f CHANNELS Pang f/ CAROLINA BEACH INLET p CAROLINA BEACH HARBOR —— | “342 CAPE FEAR END A.1.W.W. SOUTHPORT HARBOR WILMINGTON DISTRICT NEW HANOVER COUNTY SCALE OF FEET Figure 26. Masonboro Inlet Jetties, North Carolina 39 that the original 7- to 12-ton armor stone may have been an inadequate design for the incident wave environment. North Atlantic Division Baltimore District 24. The south jetty at Ocean City Inlet, Maryland (Figure 27), is the only structure within the Baltimore District that was reported as having significant toe stability problems. The original north and south jetties, both rubble mound, were constructed in 1934 and 1935, respectively. The crown elevation on the shoreward end of the north jetty had to be increased in 1937 to stop flow of sand into the inlet. The landward end of the south jetty required extensions in 1956 and 1963 to repair flanking caused by erosion. The south jetty has suffered major deterioration along its outer leg caused by ebb flow induced scour and undermining of the structure's inlet side toe. During major repair of the south jetty in 1963, the center line of the struc-— ture's repair section was offset outward from the inlet (Figure 27). This was done to alleviate the need to fill the massive scour hole that existed where the inlet side of the structure was originally constructed. The ocean side of the existing structure that remained was used as a base against which the in- let side toe of the jetty repair section was positioned. By 1982, the 1963 repair section of the south jetty was once again very deteriorated. Like the original, this damage was only on the converging portion of the jetty and was caused by ebb flow induced undermining of the structure's inlet side. In order to prevent failure of the outer end of the south jetty, which would lead to severe inlet shoaling, the scour hole adjacent to the structure was filled with dredge material and capped with stone. The lower portion of the inlet side of the jetty was overlaid with an intermediate stone size, and the remainder of the inlet side slope was covered with primary armor stone. This work was completed during 1983 to 1984, and a typical repair cross section is shown in Figure 27. The majority of the south jetty's original repair section still shows considerable deterioration and is highly overtopped. It is unknown how well the scour protection is performing. It appears that scour on the north side of the inlet has slowed down, and the north jetty is in good condition; however, the overall scour in the throat of the inlet shows no signs of stabilizing. 40 HOR. CL. 70° VERT. CL. 18° -DRAWBRIDGE S. STNEPUXENT MARYLAND . [- O.65Mi -€ PC RR. 6OR/W. _-N. HARBOR ROAD [7 = = = —F— = 10. fo} ey », W. HARBOR CESTERj# fF COUNTY 12° ke | +4.N. JETTY, +6 S. JETTY SCALE OF FEET 500 fo} 1 OCEAN SIDE CAP STONE; 6TON MIN. ABOVE -9.0; 1 500# MIN. BELOW -9 15 #TO 2 TON 1 ORIGINAL JETTY FILTER, RUN OF CRUSHER STONE 1956 NORTH JETTY REPAIR OCEAN SIDE CAPSTONE; 9 TON MIN “ELEVATIONS IN FEET REFERRED TO MLW 1’ FILTER; RUN OF CRUSHER 1 TON” 1963 SOUTH JETTY REPAIR 150° EXISTING 6.0 TO 10.0 TON STONE MIN EL FOR TOP OF ARMOR STONE (-3.0) ~a, 0.6 TO 1.0 3 OCEAN SIDE TON STONE 1 SAND A Se Co EXISTING GRADE —™ ~~ - ee FT 1983 SOUTH JETTY REPAIR Figure 27. Ocean City Inlet Jetties, Maryland 41 Philadelphia District 25. The most common problem occurring on the Philadelphia District's coastal structures is subsidence of structures below design elevation. It is thought that toe scour contributes to this, but the primary cause is poor foundation conditions in the areas where most of the structures have been built. This is especially true for those structures located in the Delaware Bay area. 26. The jetties located at Reedy Point, where the Chesapeake and Dela- ware Bay Canal intersects the Delaware River, were originally constructed prior to 1938 (Figure 28). Both structures were of rubble-mound construction. In the 1960's the existing south jetty was removed, and a new south jetty was constructed farther south. This was done to increase the entrance size to accommodate larger vessels and improve navigation safety. The present jetties are both 2,095 ft long, and it was reported that the north jetty has problems with toe scour, loss of armor stone, and overall subsidence. 27. The rubble-mound and sheet-pile composite jetties at Indian River Inlet, Delaware, were completed in 1939 (Figure 29). The jetties required storm damage repairs in 1956 and 1957. At that time, the north jetty was extended inshore a distance of 320 ft. At present both jetties are 1,566 ft long. Both jetty heads have deteriorated significantly from a combination of toe scour, armor stone slippage and displacement, and overall subsidence. Because of the success of the Manasquan River Jetty repairs, dolosse are being considered for inclusion in the repair and rehabilitation designs for the structure slopes. No details on the proposed toe repair design are available. New England Division 28. Based on review of historical repair data, it appears that three project sites within the New England Division that contain rubble-mound jetty structures have exhibited stability problems which could be related to in- stability of the structure toes. Both jetties at the mouth of the Kennebunk River, Maine (Figure 30), have a history of extension and repair. The latest jetty rehabilitation work was completed in 1982. Recent inspections show that both jetty heads are damaged and that 250 ft of the channel side of the east jetty have been undermined. The most recent inspection reports (1973-74), indicate that the north and south jetties at Newburyport Harbor, Massachusetts 42 Tf Peo Pac ‘stand evancn cnannes > envaance Delawa . > \ SURAT BRIDGE Ucn Neen Oy aie | . COUNTY IN | = KO Teese ign Pr , he 5 Gity = Baie! Sal ce) sy x OG - CMESAPEAKE CITY> “US Engineer ery BR (GH LEVEL) , Resident Office rou, Chesepeate City sy . Oy Aacheroge @ Meermg Basin 2 £ (@ece Crees! g 2 & , ST GEORGES (HIGH LEVEL) AR BR (VERTICAL LIFT) © H 5 oj $s SE = fy ad s IS AEEOY PT OR d (HIGH LEVEL) MARYL O€L aw Te Delewere Bey = LEGEND u S Reservetion Boundery , SCALE OF FEET 3.0c0 ) S 10 ic} 2c 2500¢ [SS=S5=c —- == 2: & ¢ 2 ‘Steed Bultnecd 45 HEALTH CENTER wary OR. (FIXED) 2 LANES ya SCALE OF FEET Figure 28. Reedy Point Jetties, Delaware 43 REHOBOTH BAY To Rehoboth Beach. INDIAN RIVER NECK \ DELAWARE SEASHORE STATE PARK +; CHANNEL SIDE Prevent bottom tobe axceraied to 0 depth of -3.0 Fe permit o min secton of patty 08 shown Stee! ance! poling Ihrw Mi core @ Cop stone u TYPICAL SECTION “TS. () ©, rire ANY) : a OCEAN BOTTOM HILLS DRAIN US COAST GUARD STATION 2 ag \\se'J INDIAN RIVER ——= INLET FIXED BRIOGE ELEV 35'MHW ATLANTIC ——ro Bethony Beoch TYPICAL SECTION OF REHABILITATED BULKHEADS to conus! of 0 graced (qwarry run stone, proces Mor stone{3'-0" deep) 10 conniet of preces exighing n Win! rrom notions tnon «07 1484 (ham /3 bs @ nol more than 200 D4 TNS OE Tho/! be placed for Iho tui! wi81h of 1he jally of 25% ibs 16 200 ioe Jea1t 200' in adrence of placing the Core stone 35% 200108 ro 2/008 HALF SECTION-OUTER 300! OF JETTY NTS MTS SCALE OF MILES ' ° ' _——— ———) Figure 29. Indian River Inlet Jetties, Delaware 44 Behe entSee | SWING 8B SEEDEAL See heer KENNEBUNK ~ RIVER 4 LOCATION MAP SCALE IN MILES 10 oO 10 zo 30 [es es | 6-FT. CHANNEL @ GUERTIN 6-FT. ANCHORAGE 2 ACRES 100'7| oh MONASTERY 6-FT. ANCHORAGE 4 ACRES NONANTUM HOTEL \\ 6-FT. CHANNEL KENNEBUNK RIVER CLUB SEVERANCE r) TOWN LANDING = ‘ = OCH BEACH VT: 7 8- FT. CHANNEL SAND FENCE WEST JETTY =~ sep ge & EXTENSION Figure 30. Kennebunk River Jetties, Maine 45 (Figure 31), which have an extensive repair and rehabilitation history, are showing considerable damage. This damage appears to result primarily from subsidence. Damage on four areas on the channel side of the south jetty most likely result from undermining of the rubble toe. The jetties at Hampton Harbor, New Hampshire (Figure 32), were originally constructed by the State and were turned over to the Corps in 1964. During 1965 to 1966, considerable work was done on both jetties. Since that time the south jetty has remained in good condition, while the north jetty has required continuous maintenance. Most of the repair and rehabilitation work has been needed on the seaward por- tions of the north jetty. The last rebuilding of the north jetty was com- pleted in 1980, and it is thought that part of this recurring damage can be attributed to scour and undermining of the jetty toe. North Central Division 29. There are 38 project sites within the Detroit District which have breakwater and/or pier (jetty) structures that have exhibited stability prob- lems related to the structure toes. At 14 of these sites problems are associ- ated with rubble-mound structures, while at the remaining 24 sites toe prob- lems occur on other structure types. Table 2 is a listing of these 24 sites and the types of breakwater and/or jetty construction associated with each site. The remainder of this section on the Detroit District deals strictly with those 14 sites which are having and/or have had toe stability problems with rubble-mound structures. At some of these sites, toe stability problems have occurred on areas of the structures that are not rubble mound. 30. Structures at Black River Harbor, Cheboygan Harbor, Hammond Bay Harbor, Harrisville Harbor, New Buffalo Harbor, and Point Lookout Harbor, Michigan, are purely rubble-mound construction (Figures 33-40). Charlevoix Harbor, Michigan; Duluth-Superior Harbor, Minnesota and Wisconsin; and Leland Harbor, Muskegon Harbor, Pentwater Harbor, Port Washington Harbor, and Traverse City Harbor, Michigan (Figures 41-55), have structures that are com- posed of a combination of rubble mound, timber cribs, timber piles, steel sheet piles, concrete caissons, steel cells, concrete caps, and concrete superstructures. The head of the east jetty on the north end of the Keweenaw Waterway, Michigan (Figures 56 and 57), is an old timber crib which is encased in rubble. For this reason, its response is very similar to that of a purely 46 9.0 FOOT CHANNEL (12-FT. DEPTH NOT DREDGED-|NACTIVE) Figure 31. @ANCHESTER LOCATION MAP SCALE IN MILES paease NORTH JETTY ~~ SHORE REVETMENT 12 FOOT CHANNE (15-FT. DEPTH NOT DREDGED- INACTIVE) CROSS SECTION OF NORTH JETTY TOP OF MOUND EL.12° RIVER SIDE 7——\_ _M.H.W. EL. 7.8' aprii on U.L.w. EL. 0.0 hl od = EXISTING BOTTOM CROSS SECTION OF SOUTH JETTY SCALE IN FEET 1000 2000 Newburyport Harbor Jetties, Massachusetts 47 NEW HAMPSHIRE i @ cCoNcoro é LOCATION MAP SCALE Im MILES ganting ground surtoce - E110 9-90 (vores) 7 NORTH JETT Y— SECTION SCALE im FEET . o > STONE JETTIES ry HAMPTON® HARBOR 8-FT. ENTRANCE CHANNEL =) Ore Inner Sunk Rocks SOUTH JETTY SECTION SCALE m FEET * ° 3 SEABROOK SCALE IM FEET Figure 32. Hampton Harbor Jetties, New Hampshire 48 Table 2 Project Sites in Detroit District with Toe Stability Problems on Other Than Rubble-Mound Structures Types of Structures at Location Project Site* Algoma Harbor, Wisconsin TP** and TC w/CS Areadia Harbor, Michigan SC and TC w/SSP Big Bay Harbor, Michigan RM, SC and SSP Frankfort Harbor, Michigan G5 WP, SP5 SGy SSR25 CS ema Ger Grand Haven Harbor, Michigan Se5 IH, GS eimel EGP Harbor Beach, Michigan TC and CS Holland Harbor, Michigan SSP, TC, RM, TP, CS and CCP Kenosha Harbor, Michigan G5 SSP, SG5 GEP emma CS Kewaunee Harbor, Wisconsin TP, CC, RM, SSP, SS, CCP and CS Lac La Belle Harbor, Michigan SC and SSP Ludington Harbor, Michigan TC Lee SOSP RM, (CGR and ics Manistee Harbor, Michigan Soe, ING, IWe5 ame CS Manitowoc Harbor, Wisconsin We, G65 Woy SSP5 IM, emal ES Menominee Harbor, Michigan and Wisconsin S125 6, GG, Ca? aml CS Milwaukee Harbor, Wisconsin TC, SSP, CC, RM, CCP and CS Portage Lake Harbor, Wisconsin TC, TP and CS Racine Harbor, Wisconsin WG, WP, IMI, SSP, CG, Gee ame GS Saugatuck Harbor, Michigan WG, 12, SSP5 amal CS Sheboygan Harbor, Wisconsin WG, WP, SSP, smal CS South Haven Harbor, Michigan SSP, TC, CCP, and CS St. Joseph Harbor, Michigan AG, S25 GIP ehial CS Sturgeon Bay, Wisconsin TP, TC, SSP, and CS Two Rivers Harbor, Wisconsin TP, TC, SSP and CS White Lake Harbor, Michigan WP, IEC, emal CS * Not all structure types at each site are experiencing toe problems; how- ever, tabulation presents all structure types existing at each site. *x TP-timber piles; TC-timber cribs; CS-concrete superstructure; SC-steel cells; SSP-steel sheet pile; RM-rubble mound; CC-concrete caisson; SP-steel piling; CCP-concrete cap; SS-steel sheeting 49 -—\7 =f je f yi Note Projec! depths ond soundings are referred to LWD 600.0 feet | above MWL at Father Point, Quebec (IGLO 1955) (International VICINITY MAP Great Lokes Datum 1955). "99 'p 2 30 40 S0 Op 70 eo SCALE IN MILES GOGEBIC COUNTY (Gl eRseeraree ies 2 MICHIGAN BOAT RAMP=——=P (reel) ; hoe == Suspen Foot Bridge 18 ft. clearance B@LAC K RIVER CLORURINIE any. Poy O03 Parking Area eo SCALE IN FEET Figure 33. Black River Harbor Breakwaters, Michigan 50 Lakeward End to -5 Ft. Contour -5 Ft. Contour to +2Ft. Contour SCALE 10 io) 10 20 FT = +2Ft. Contour to Landward End RUBBLE MOUND - BUILT 1957 EAST AND WEST BREAKWATERS Eos! Breokwoter-825 FI. + UOTE u es, Breokwoter-555 Ft. + Figure 34. Details of Black River Harbor Jetties, Michigan 51 LAKE HURON 8 / =I / 7, 16.1.0. EL 576.8' /),’ 0 G o r 0 ” 2 ty! Ue : > STRAITS OF “M AC KIN LA C2 / 2 3 / G2 / & ‘4 s\n S ” 7) Cheboygon Crib Lt Ws \ #L/ Nos N w 40 ° 25 10 o 22 hl 27 2 0 D 2s Little ee SS Sa 10 SS 10 PROJECT DEPTH 2/ FT. ¥ Qs, 2 5 F : -= == ’ oF > As A = a = a = A -~ = - us = - -_ > _ a > -_ -_ sie eae WM we An A 104 P g ae x Atl, 3 TURNING BASIN PROJECT DEPTH 2/FT. — = R g z isin & MICHIGAN E y oS S oer ho oR = ‘ 37 soszen fen PROJECT DEPTH (ave INDIANA onIo _ \ VICINITY MAP. “| SCALE OF MULES a s 16 0 PRI h 4 | el a OTE CTs DEPTH 8.5F. 3 3 la] COVER STONE a 5 CHANNEL SIDE WEST CHANNEL CINE I-TOE STONE WEST PIER ‘o| 4 TON MIN LAKE si0g 2TONMIN RUINS OF OLO Ss fae two EL 576.8" CORE STONE MATTRESS STONE TLEVELARD EXISTING coma f>—Lwwc. tock SECTION A-A TYPICAL SECTION OF RUBBLE-MOUND BREAKWATER SCALE OF FEET = 5 4 Figure 35. Cheboygan Harbor Breakwater, Michigan 52 COVER STONE PROJECT DEPTH ENTRANCE CHANNEL /2 FT HARBOR BASIN IO FT _ CHANNEL WIDTH VARIES EXISTING BOTTOM TYPICAL SECTION SCALE OF FEET VERTICAL HORIZONTAL MICHIG ENTRANCE CHANNEL PROJECT DEPTH 12’ MICHIGAN MICHIGAN INDIANA VICINITY MAP SCALE OF Bai MICHIGAN STATE HIGHWAY PARK AREA HIGHWAY les PUBLIC ACCESS AREA FOR HARBOR Project depths, saundings ond elevations are referred to Internationa! Great Lakes Datum (1955) for Lake Huron , elevation Scale of Feet 700 576 6ft above Mean Water Level (MW.L.) at Father Point, Quebec ""p o tao 200300400800 800 Figure 36. Hammond Bay Breakwater, Michigan 53 NOTE: Cover stone 5 ton minimum in types 1 and 1 3 ton minimum in types II ond I oe Toe stone 7 ton minimum in types I ond I; 5 ton minimum in types If ond I t ee I] wacxway FA ee BB HARBOR SIDE LAKE SIDE o TYPES Row * D> ' G.L.0. El 5768" Ro ——} ae) uy “ 3 ;) CORE STONE Y_ } ia R roe stonk ¢ A ——MaTTRESS STONE a AKE BOTTOM TYPICAL GROSS TI Scole of Fest VICINITY MAP SCALE OF WiLeD ALCONA COUNTY | A NOTE Project depths, soundings and elevations are referred to International Great Lakes Datum (1955) for Lake Huron, elevation 576.8f1. above Mean Water Level (MW.L.) at Father Point , Quebec. SOUTH BREAKWATER EXPANSION OF STATE BERTHING ~ FACILITIES 3. 15.7 HARGOR BASIN / 10 FEET OEEP on 12.0 15.2 ‘ g ’ Bs ENTRANCE CHANNEL Wo YF te Ob 12 FEET DEEP 1.G.L.0. El. 576.8" Scale of Feet 100 0 100 2 3 5 6 7 6 9 1000 SS Figure 37. Harrisville Harbor Breakwaters, Michigan 54 (WISCONSIN rm n Vo w ° EXPERIMENTAL VICINITY | MAP "a" FRAME BREAKWATER REACH -F ' SCALE OF! MILES REACH-A 480'+ 300 40 VILLAGE PROJECT DEPTHS AND SOUNDINGS ARE REFERRED TO LOW WATER DATUM 576.8 FEET ABOVE MEAN SCALE OF FEET WATER LEVEL AT FATHER POINT, QUEBEC. |.G.L.D. =Ss=o=————r (1955) (INTERNATIONAL GREAT LAKES DATUM) ° 200 400 Figure 38. New Buffalo Harbor Breakwaters, Michigan 55 12-0" AVERAGE |2 TON COVER STONE ¢ ( RANGE 10 TO 16 TONS) EXISTING —=LAKE BOTTOM CORE STONE (100-LB. TO1 TON PLACE LARGER STONE ON OUTSIDE) 2-0" BEDDING STONE (I-LB. TO 50-LB QUARRY SPALLS ) 16 TON TOE STONE REACH-A BUILT 1975 ¢ AVERAGE 6 TON COVER STONE (RANGE 5 TO 10 TONS ) EXISTING ZLAKE BOTTOM CORE STONE (I-LB. TO 1,000-LB PLACE LARGER STONE ON OUTSIDE) 2-0" BEDDING STONE (1-LB. TO 50-LB. QUARRY SPALLS ) 10 TON TOE STONE REACH-B BUILT 1975 AVERAGE 4 TON COVER STONE ¢ Leo! (RANGE 3 TO 5 TONS ) EXISTING LAKE BOTTOM ra a aor 5 TON TOE STONE 2'-0" BEDDING STONE (1-LB. TO 50-LB. QUARRY SPALLS ) CORE STONE (1|-LB8. TO500-LB PLACE LARGER STONE ON OUTSIDE ) REACH-C BUILT 1975 fe) (e) 10 20 CORE STONE (I* TO 500°) PLACE LARGER STONE OUTSIDE AVERAGE 3 TON COVER STONE (2 TO 4 TON) SCALE OF FEET EXISTING LAKE 2-0" BEDDING STONE (1° TO 5O0°QUARRY STONE) REACH-D BUILT 1975 Figure 39. Details of New Buffalo Harbor Breakwaters, Michigan 56 1/4 TON MIN. VARIES +9° TO+I2 rors! COVER STONE aac tan ey \/4 TON MIN 2/3 TOMMIN ccs TONMIN j Zee: STONE \ Yi 172 TON MIN 11/2 TON MIN, 11/2 TONMIN: 1/2 TON MIN- H { TOE STONE TOE STONE TOE STONE TOE STONE MICHIGAN 2 MATERIAL TO BE EXCAVATED LAKE vote re SECTION A-A on Leute NO SCALE ‘VICINITY MAP SCALE 10 0 100 Mi = SAGINAW OF CULVERT 8+00 18+00 "2 : ~ : DOWNSTREAM : : LIMIT OF FEDERAL PROJECT- WEST ng j JETTY /OFT. PROJECT DEPTH : 12 FT. PROJECT DEPTH: NOTES: Project depths, soundings & elevations are referred to International Great Lakes Datum (1955) for Lake Huron; Elev. 576.8 ft, above Mean Water Level at Father Point, Que. Figure 40. Point Lookout Harbor Jetties, Michigan 57 ueSTyotTW ‘Ssetaqer Aoqzey xPoneTseyD “1H ein3tq oe 08) Gaim 40 av2s NTOONIT dV¥M ALINIDIA wo 4 VNVIGNI > ey 0 m ce : PCED ei ine qunH | vOH 2901N8 NVOIHIIN INT EPEDEDSED) 331Sinvn Y agnviqsi > Ae OILS 7 a7rg7 “2907 ONN0H¥ NOLNIT9 os NvaYor 1Sv3}H > ee Gem br Lo3dSO0ud 4IVHD TIVNS YOF VIAY IOVYOHINY SNVAU3HLVIM oz «OF 0 1334 40 3195 d¥W NOILV907 : NVOlLHIOIW"” STOHIIN 4s A3NSOL3d 58 SAFETY L 33.0° € RAILING r | zh , x as | 46.75! Z-27STEEL SHEET PILING Z-27 STEEL SHEET PILING pis P T- SUBSTRUCTURE 1079-80 Hposr STEEL SUPERSTRUCTURE 1078-9,1007-9 Bh oag =25.17' PILING 25125) REHAB 190! 35.01' DIA SECTION—-AI -38.75" = = =| SS | ye ceELL NORTH PIER _+7.0' BUILT: SUBSTRUCTURE 1679-80 i a F SUPERSTRUCTURE 1676,1667-9 are 7 45.25" REBUILT 1966 bs 1G.L.0._ 5 Bei 76.80 _j—$-28 s-28 | | STEEL PILING STEEL PILING 1 lJ a | 1 o | i ‘ f | I | | | el eee —--}---- eg ee al HER Kelop SIE Cum hOUNi—vANe NORTH PIER BUILT i966 FE icd SAFETY RAILING icGuo 576 8° WALKWAY SECTION-B NORTH PIER BuILT 1897 REHAB 1981 SER al : : 276.8" | e210 z-27 STEEL PILING—\- STEEL PILING CHANNEL -9.5' Scale of Feet "B % 2 on 30 40 arpa SECTION-—F SOUTH PIER ACBUILT 1930 PEPAIRED i966 Figure 42. Details of Charlevoix Harbor Jetties, Michigan 59 uTSUODSTM pue eJOSeUUTW ‘SteqeMYeeIg pue set ef Joqiey AOTAedns-yan[ng “Ey eANsTy alee Oboe ae oo 4334 i_31¥95 a BG «| : S500 ODE OD Qy Q “e; Lp o Xs "Vos ye = =| = (ol "7 Lal il Oo [oa eel aa cma) e LQ A raga Sere ® Q i (| [oa] (es) le) ea} CO onthe! 0 Ol (onl) 0 ON ¥ kL er Ss: Z osh oS & J Gsose ‘ J 5 ¢/ Vl I ss 60 pay citya fh a -PSacinaw °- VICINITY MAP SCALE OF MILES 100 50 100 D CAUTION Y sicn Va © MICHIGAN 1.6.4.0. EL. 576.8’ NOTES: Project depths, soundings and elevations are referred to International Great Lakes Datum (1955) for Lake Michigan, elevation 576.8 ft. above Mean Water Level (M.W.L.) at Father Point, Quebec. Scale of Feet “€bap 100 ° 100 200 ————————_———S=_—SSSSSSSSS==SS=) Figure 44. Leland Harbor Breakwater and Jetty, Michigan 61 je DIA 17.5' = 2 eae 3 oO re a ES he ‘ (one fe | Neale YU Sa : Re AGGREGATE (ARIE re = CELL FILLY hal £2. Jo >): 3 ive | | ee —SP-6 STEEL SHEET PILE =21.5° SECTION-B BUILT: 1936 REPAIRED: 1952 REHABILITATED: 1966 € 250-1000L 8.! STONE | S-28 STEEL SHEET PILING —+ ER eee oe = el uJ oO = SECTION-A i¢p) CONSTRUCTED: 1968 8'-0" [sa BS 576.8 a ot Hs ; IPRs a bGLO, CLOSE PILING STONE MATTRESS SECTION-C BUILT: SUBSTRUCTURE: 1936 CONSTRUCTED: 1968 COVER STONE 5 TON MIN. LAKE SECTION I -10' SECTION I-8' 1G6.L.D. STONE MATTRESS SECTION-D RUBBLE MOUND BUILT: 1941-3 TOE STONE 7 TON MIN. EXISTING BOTTOM ~ TYPICAL CROSS SECTION-RUBBLE MOUND BREAKWATER CONSTRUCTED: 1968 576.8' LAL.0. STEEL SHEET PILING SECTION—E stv! vn SHORE CONNECTION QUILT! 1946 Figure 45. 62 Scale of Feet ee Details of Leland Harbor Breakwater and Jetty, Michigan SIDE HARBOR 35 UPSTREAM LIMIT OF TAT! SUMS Galas FEDERAL PROJECT 32 PROJECT DEPTH USK EGON 35 LAKE > 44 NAVAL ” - be —. @ s \ % 2 %, By a 6 XY 98 CANADA 30 MUSKEGON . 3 w) ra COUNTY 2 Ce) /GLO ELEV 576.8" # 7 2 v q MANISTEE 2 bd iS = S = ww x x s INDIANA VICINITY MAP r SCALE OF MILES A NOTES ; Project depths, soundings and elevations are referred to NORTH Isternational Great Lakes Datum (1955) for Lake Michigan, elevation MUSKEGON 576.8 ft above Mean Water Level (MW.L.)at Father Point, Quebec. Scale of Feet 500 o 500 1000 1500 2000 nt LOCATION MAP MICHIGAN ‘ SCALE OF FEET 4 ° 3,000 10,000 5,000 ul Figure 46. Muskegon Harbor Breakwaters and Jetties, Michigan 63 =— 255' TO 195! A -aquarry RUN B -1 To 5 Ton C- 4 TO 5 TON D - 8 To 10 TON _ _576.8'_ IGLO SECTION -—A NORTH BREAKWATER out 1930-1 3 veal SECTION-B | NORTH BREAKWATER BuILT 1930-1 SAFETY malenas| OUTER 54 LINEAR FEET OF SECTION "C" CONSISTS OF 2 RECTANGULAR CAISSONS Wow We WNW SECTION — SOUTH BREAKWATER But SUBSTRUCTURE 1927-30 SUPERSTRUCTURE 1927-30 10. i i. it ne 3 3 3 —+71' - P SAFETY RAILING [4 fo} a a < : Lye = VS NY oH coRECTION TE. SECTION — O ovicT suastmucture 1927-30 SOUTH BREAKWATER SUPERSTRUCTURE (3877/39 i ounT BUOSTRUCTURE 1927-30 . % ° . SAFETY RAILING tT gupERSTRUCTURE 1027-30 liam 1 SAFETY RAILING LAKE SIDE ene Toe STONE SEGTION=G SOUTH BREAKWATER BUILT SUBSTRUCTURE 1926-30 SUPERSTRUCTURE 1930 UNDER CONSTRUCTION 1966 MATTRESS STONE SECTION-F SOUTH BREAKWATER BUILT: SUBSTRUCTURE 1926-30 SUPERSTRUCTURE 1930 UNDER CONSTRUCTION 1966 SAFEVY RAILING Scale of Feet 10 ° 10 20 yo 40 576.8' eee —$—— ees: } SECTION-H SOUTH BREAKWATER BuILT SUBSTRUCTURE 1920-30 SUPERSTRUCTURE 1930 Figure 47. Details of Muskegon Harbor Breakwaters, Michigan 64 HARBOR OR CHANNEL SAFETY RAILINGS (TYP.) + 8.5' Z IML, i PRS Scale of Feet 10 te} 10 20 30 40 TYPICAL SECTION NORTH PIER BUILT: SUBSTRUCTURE 1906 SUPERSTRUCTURE 1933-4 REHAB. 1980 S.R 1904 SECTION - N LOS) SOUTH PIER BUILT: SUBSTRUCTURE 1875 SUPERSTRUCTURE 1932-3 REHAB. 1966 -45.5 TYPICAL SECTION - O SOUTH PIER BUILT: SUBSTRUCTURE 1668,96°99 SUPERSTRUCTURE (932-3 REHAB 1966 Figure 48. Details of Muskegon Harbor Jetties, Michigan 65 1GL.D EL. 576.8" CHARLES MEARS STATE DUMP GND. 1-1/4 HI, & E @ 270° AZ MAINTAINED TO 12FEET SUBM. CABLE UPSTREAM LIMIT OF FEDERAL PROJECT LIMITS OF APPROVED PROJECT- NOTE: Work remaining to be done shown thus: Project depths,soundings,and elevations are referred to International Great Lakes Datum (1955) for Lake Michigan, elevation 576.8 ft. above Mean Water Level (M.W.L.) at Father Point, Quebec. Scale of Feet 500 ——— INDIANA ' VICINITY MAP Scole of Miles CONCORD ‘90 5 ! N T WA EOWELIE STREET STREET FIRST STREET il SECOND STREET THIRD STREET Figure 49. Pentwater Harbor Jetties, Michigan 66 SIDE CHANNEL 2470 28° +7" SECTION— A NORTH PIER BUILT SUBSTRUCTURE 1872,99 SUPERSTRUCTURE 1938 BUILT SECTION—- D NORTH PIER SASBNAR| SECTION— B SECTION ar 576.8" (esmore= = — FH SZLERGE SECTION — C N. 8S PIER NORTH PIER NP SP BUILT SUBSTRUCTURE 1870,98899 SUBSTRUCTURE 1870,98499 869,99 SUPERSTRUCTURE 1938 SUPERSTRUCTURE 1938 1938 =JE SECTION -G NORTH PIER SOUTH PIER BUILT SUBSTRUCTURE 1870,98 6 99 BUILT SUBSTRUCTURE 870,898 BUILT SUBSTRUCTURE 1887,9 SUPERSTRUCTURE 1938 SUPERSTRUCTURE (938 SUPERSTRUCTURE 1938 +7 576.8" SOUTH PIER SOUTH PIER BUILT SUBSTRUCTURE 1870,99 BUILT SUBSTRUCTURE 1868,99 SUPERSTRUCTURE 1938 SUPERSTRUCTURE 1938 10-0" 4 TOE STONE ‘ 9 TON MIN a i 2 es LINE 1 Scale of Feet MATTRESS STONE ad 10 0 10 20 30 a0 / \ (2820-82828 = ————— —— —— TYPICAL RUBBLE MOUND SECTION BUILT 1959 Figure 50. Details of Pentwater Harbor Jetties, Michigan 67 ST. UPSTREAM LIMIT OF FEDERAL PROJECT 6 WISCONSIN ST. FRANKLIN GRAND AV U.S.141 & ST HWY. 32 : Y RIVER STATES (o} IPSTREAM LIMIT OF FEDERAL PROJECT MICHIGAN 27 27 PROJECT DEPTHS AND SOUNDINGS ARE REFERRED TO LOW WATER DATUM 576.8 FEET ABOVE MEAN WATER LEVEL AT FATHER POINT, QUEBEC. 1.GL.D. (1955) (INTERNATIONAL GREAT LAKES DATUM ) SCALE OF FEET I = i = 200 400 600 600 1000 VICINITY | MAP SCALE OF NILES CoAT 1 MILWAUKEE o = ct 4 Figure 51. Port Washington Harbor Jetty and Breakwaters, Wisconsin 68 SIDE HARBOR SUPERSTRUCTURE ON SOUTH BREAKWATER 1-6 BELOW TOP OF CAISSON. NOTE: OUTER 54 LINEAR FEET OF SECTION A, NORTH BREAKWATER, CONSISTS OF TWO RECTANGULAR CAISSONS. N NORTH & SOUTH BREAKWATER NB SB BUILT’ SUBSTRUCTURE 1934 1936 SUPERSTRUCTURE 1934 1936 CAP STONE GROUTED IN PLACE +7.5' PILES ARCH CELL TYPE cd ro oop 9, P0004 aw 2Naa0.60-7--S8sle i} -19'To-27' SECTION-B SECTION-D NORTH BREAKWATER NORTH BREAKWATER BUILT: SUBSTRUCTURE 1934 BUILT: 1934 SUPERSTRUCTURE 1934 +7.0' STEEL SHEET PILES BUTTRESS, SINGLE WALL TYPE Lw.o 13:1 SLOPE t1 SLOPE i gl ig LUA = To-17 FRO PPPOE PPS SECTION-E NORTH SHORE CONNECTION SES VOWS Quit 34 NORTH BREAKWATER SCALE OF FEET BUILT: SUBSTRUCTURE 1934 SUPERSTRUCTURE 1934 L} ° 0 20 %» Figure 52. Details of Port Washington Harbor North and South Breakwaters, Wisconsin 69 KF 2 teres wig 7 7 SAND & EARTH ty FILL Beye ™ en ee) i =| (i an H Sy a j | N Nu uJ (2) 7) SECTION-F SECTION=-G x NORTH STUB PIER NORTH STUB PIER BUILT: 1940 BUILT: 1940 (eo) ao a ‘ 6 < +8.7- lr a x= —_ —L.W.D. 576.8 53% Sa a eS J G NY > fo) & e, ‘a> 0 Ce 4 £ON Aptech OF erSZ Orn oc) eat TH by YB Weamleat.aet 4 WJ SECTION-I z Zz WISCONSIN ELECTRIC POWER CO. < x U SECTION —J SOUTH BREAKWATER BUILT: 1936 SCALE OF FEET [=o 50S eS Se ee SS) $ [*) Le) 2 30 4 Figure 53. Details of Port Washington Harbor North Jetty and South Breakwater, Wisconsin 70 uesTyoTW 1m ae woguyw |e! ALID 9SU3AVUL ¢ ywo bat ai (WHY LSIM) g ISHIAVHL ONvVY9 Van. wois wotunya 4] ‘szozemyeorg 1oqaey AITO eSreAeAL, “*yG eAN3Ty — = Ene oes othe GVM ALINIDIA frital 1000 710) Dera (uanao) 03) owt me ALNNOD NWNV1337 w3uv 193°0ud 1900 218M dITHSHMOL QOOMATZ anvu PMmONNWT LvOo “] vinuve mouuva ~ (wav L575M) Ava IsHIaAvHd Nisva aNiuvy MOWuWO aonvyd 71 uesTyotW ‘Sszeqemyverg zoqzey AIF) estoaety, JO STPRICT 9961-171N8 ys UalvVMyVaua ONNOW 3188Ny—NOWI3S WOIIdAL 1661-1718 YyBLVMNV3NB8 Y3LNO @-8 NOILI3S "Gg aansta ——s — ES 2-8-8) [e) ol Ov Of ,8101,S JTEVINVA {aaj 40 0109S waivanvaue eee! sATING oeel aaine @-NOILIISS W-NOILOIS z- 0 w-0 —_ aa — 13aHS 133916 2¢-Z Te 301s Ne gas yosuvH yOGuWH T+ c+ 9961 :171N@ —_—-— + 4H9I1 YOS uOuans t—se2- YILVMAVINB 1S3M vV-v NOILI3S ————-7-08e- ONITId 13318 O2-S Geer eee 3NO1S 9NIO038 Pon “NOD Q32NO4NIZ.9-—2 | ~ 3d0TS 72 uesTYyOTW SAeMI07eM MeUdeMeY ‘SiojJeMYeerg VoOUeTIUY aeddg ‘*g9¢ ean3Ty 183m ¥ 1SV3 S3°Ym mi 39995 Cre a BONVULNS B3ddN \ 1LOaS dUW ALINISIA 4324 Mi 37095, Na S oF * : 5 Z j ie ion rw A oo nee nN x NVOIHOIW Prinnos || \noLHonoH Fie: : ah |, F ‘ sr = 5 Las oI a “ at - as Vv : Se (ey, : a poopy Aiunoy — lo, 7) “% i BS (S561 wniog sP¥07 | © vw» = S x‘ $OaD JOUVE jOUs01 UI) 1 7191) FREAD "W9g 4H 10 TMI BAOG0 j ; 2 aa aD anon ie cD CA | | mss i ; a BE “aay Fanaa Sater A 2 5 : m z0ns7e 40 copatH |S ONOd A7!7 im 403, . 19V3 S52 JONVHLN3 H3ddN 9 NOILOAS 3018 34v7 whee omy S3UNLONYLS OVIHY3Id YILVMNVIEB BONVHIN3 H3ddn V_ NOILOSS Si BaP 99u0JjU7 Jeuop—— oA Ate ™, I >, he aoa 73 uesTyotW ‘Aemi107eM MeuUUAMey ‘iejeMyYeeTg aoUeAQUY AeMOT */cG aAN3Ty dVW X30NI = a 2ov0s4u7 Jamo), AVE MYNIIMIN BONVYLN3S —¥3MO7 TNOILOSS ma] ee 3018 YORYVH (SS61 wnjog s6x07 joH9 Jouo!4ousB1¥) | (S56) O71) 22G8ND ‘iuIog YeYIOs 10 TMIY B4090 490) 9009 GM 0} pess24+s 940 sbuIpUNOS puo Fysa—p j22!01g NOILO3S SSOUD WOIdAL NOILO3LONd dvudie 3ONVHLN3 Y3MO7 4334 Mi 9109S : WOT wu: 000) a IavIWYA MOLDKARIO NVOIHOIW| ALNNOD NOLHO NOH esy vo}\0e.08y. vig bursoon se abo,s0d) C se 790438 40 8. 5a 0 DIAGE 0 : 1 3 7 waa cle eo (Aste7 wavee ae f Fen 2 psang.t009 5 04) Kua Ausodoua sn Xhssiv soy Xe N.ajqos sv0udajay ausowgns NOISN3LX3 B3LVMNY 388) Peoy Ayuno> 74 rubble-mound structure. The remainder of the structures at Keweenaw are tim- ber crib with some rubble and steel sheet piles. 31. In general, the rubble-mound structures in the Detroit District that show toe stability problems have shown the results of this problem through damage to the upper slope and crown armor. It is not known defi- nitely, but it is expected that the toe damage is a combination of toe armor instability combined with foundation scour and undermining of the structure toes. Repair to a structure is carried out by filling the scour holes with stone and then reshaping and repairing the structure's armor stone layer(s). Some repairs have been successful thus far, while other areas require frequent repair work. 75 PART III: DISCUSSION 32. In general, there appear to be three major problem areas with rubble-mound coastal structure toes. One of these pertains to the proper sizing and placement of toe buttressing stone. The purpose of the buttressing stone is to stabilize the onslope armor by preventing downslope slippage of the armor layer. For these stone to function properly, they must be of suf- ficient weight and placed in such a way that they are stable in a wave and/or flow environment. The second major problem area concerns toe berms. A toe berm's primary function is to protect a structure placed on an erodible bottom from being undermined by wave- and/or flow-induced scour and to resist down- slope slippage of the armor. For a toe berm to function properly it, like the toe buttressing stone, must be composed of materials and be constructed in a geometry that will be stable in the incident wave and/or flow environment. Thirdly, toe buttressing stone and toe berms are susceptible to damage and failure when placed on an erodible bottom material. The stone may be sized adequately for the level of energy to which they are exposed, but the exposed bottom material at the outer perimeter of the structure may readily erode and/or an inadequately designed bedding material may allow the foundation material to migrate through it and the toe berm armor. Either one or both of these factors can result in the undermining and displacement of stone that were otherwise able to withstand the wave and flow environment but failed because of undermining induced displacement. 33. In summary, a toe failure may be the result of any one or a combi- nation of the above. Guidance exists for proper design of bedding (filter) layers based on soil types, but very little guidance is available for the siz- ing and geometries needed for the proper design of toe berms and buttressing stone for incident wave environments. Most work done by the districts in these areas is based on field experience and engineering judgment. A scouring bottom is a problem in itself. No matter how well a toe is designed, if the local bottom materials (sands, silts, clays, etc.) are exposed to sufficient energy levels for scour to occur, the toe of the structure is doomed to fail- ure unless the toe berm is extended out to a point where the energy levels are below those which will initiate scour. In most cases this is not practical or feasible. In these instances, sufficient toe berm material, that in itself is stable for the wave and/or flow environment must be placed so that as the 76 structure toe undermines, the berm material can slough off into the scour hole. This will provide some armoring to reduce the rate of scour and thus increase the usable, or functional, life of a structure. 77 PART IV: CONCLUSION 34. Based on extensive discussions with Corps division and district personnel and after the review of prototype experience relative to rubble- mound toe stability problems, it is concluded that design guidance is seriously needed on the proper sizing and placement configurations needed to provide adequate buttressing stone and toe berms for rubble-mound coastal breakwaters and jetties. Once it is understood how to design toe berms and buttressing stone for a range of water levels and wave conditions, these designs need to be incorporated into a test series that addresses the way in which varying toe geometries influence localized scour. The latter will pro- vide some qualitative insight into how a toe berm can be configured or positioned to reduce the quantity and/or rate of localized foundation scour. 78 i =) RN isk he IK: ha sone