Post on 03-May-2018
The University of the West Indies Organization of
American States
PROFESSIONAL DEVELOPMENT PROGRAMME:
COASTAL INFRASTRUCTURE DESIGN, CONSTRUCTION AND MAINTENANCE
A COURSE IN
COASTAL DEFENSE SYSTEMS I
CHAPTER 11
STRUCTURAL DESIGN
By DAVE BASCO, PhD Professor, Department of Civil and Environmental Engineering
And Director, the Coastal Engineering Centre, Old Dominion University
Norfolk, VA
Organized by Department of Civil Engineering, The University of the West Indies, in conjunction with Old Dominion University, Norfolk, VA, USA and Coastal Engineering Research Centre, US Army, Corps of Engineers, Vicksburg, MS, USA.
St. Lucia, West Indies, July 18-21, 2001
STRUCTURAL DESIGN OFSTRUCTURAL DESIGN OF
David R. Basco, Ph.D, P.E.Director, The Coastal Engineering Center Old Dominion University,Norfolk, Virginia
USA 23529 basco@cee.odu.edu
COURSE ORGANIZATIONCOURSE ORGANIZATION• Course 2.1: Design of Coastal Structures I
- Stability of loose-material structures (breakwaters and revetments)
- Case studies: Introduction, Example Problems VI-7
• Course 2.2: Design of Coastal Structures II- Design philosophy; probabilistic design methods- Role of damage in coastal structure design- Cross-sectional design (breakwaters/revetments)- Balanced design prinicples- Case study
• Course 4: Design of Marine Structures- Seawalls and bulkheads- Beaches- Example problems VI-7 Armor Layer Stability
Coastal Engineering Practice CommitteeCEM Preview
Steven A. Hughes. Ph.D., P.E.Coastal and Hydraulics Laboratory
US Army Engineer Research and Development Center
David R. Basco. Ph.D., P.E.Coastal Engineering Center
Old Dominion University
Coastal Engineering Practice CommitteeCEM Preview
Overview of Armor Layer StabilityRubble-Mound Trunk and Head StabilityRiprap and Toe StabilityCross-Section DesignExample Problems
CEM Chapter VI-5-3 (Author: Hans F. Burcharth)CEM Chapter VI-7 (Author: David R. Basco)
Based on:
Coastal Engineering Practice CommitteeCEM Preview
Movement of armor units• Rocking• Displacement from layer• Sliding of layer• Settlement of layer
Not armor unit breakage
Coastal Engineering Practice CommitteeCEM Preview
Parameter Stability Equation
Coastal Engineering Practice CommitteeCEM Preview
Sea State Variables• Wave height• Wave length• Wave steepness• Wave angle• Wave Asymmetry• Spectrum shape• Water depth• Water density
Structure Variables• Armor layer slope• Freeboard• Armor density• Armor gradation• Armor weight• Armor shape• Packing density• Layer thickness• Porosity of layers
Coastal Engineering Practice CommitteeCEM Preview
Coastal Engineering Practice CommitteeCEM Preview
Coastal Engineering Practice CommitteeCEM Preview
Classified by:• Type of armor unit• Water depth• Superstructure• Dynamic• Crest elevation
• Non-overtopped• Low-crested• Submerged
• Based on small-scale physical models• Testing of designs is recommended• Always test unusual designs
Model Testing
Coastal Engineering Practice CommitteeCEM Preview
Coastal Engineering Practice CommitteeCEM Preview
Overview of Armor Layer StabilityRubble-Mound Trunk and Head StabilityRiprap and Toe StabilityCross-Section DesignExample Problems
CEM Chapter VI-5-3 (Author: Hans F. Burcharth)CEM Chapter VI-7 (Author: David R. Basco)
Based on:
Coastal Engineering Practice CommitteeCEM Preview
Design Guidance for These Situations
Hudson’s Equation
Coastal Engineering Practice CommitteeCEM Preview
Coastal Engineering Practice CommitteeCEM Preview
Coastal Engineering Practice CommitteeCEM Preview
Coastal Engineering Practice CommitteeCEM Preview
Coastal Engineering Practice CommitteeCEM Preview
Coastal Engineering Practice CommitteeCEM Preview
Coastal Engineering Practice CommitteeCEM Preview
where
Coastal Engineering Practice CommitteeCEM Preview
Overview of Armor Layer StabilityRubble-Mound Trunk and Head StabilityRiprap and Toe StabilityCross-Section DesignExample Problems
CEM Chapter VI-5-3 (Author: Hans F. Burcharth)CEM Chapter VI-7 (Author: David R. Basco)
Based on:
Coastal Engineering Practice CommitteeCEM Preview
Gradation Range:
with
Coastal Engineering Practice CommitteeCEM Preview
Design guidance for:• Sloping trunk and head• Vertical trunk and head
Toe berms…• Support main armor layer• Prevent damage by scour
Coastal Engineering Practice CommitteeCEM Preview
Coastal Engineering Practice CommitteeCEM Preview
Overview of Armor Layer StabilityRubble-Mound Trunk and Head StabilityRiprap and Toe StabilityCross-Section DesignExample Problems
CEM Chapter VI-5-3 (Author: Hans F. Burcharth)CEM Chapter VI-7 (Author: David R. Basco)
Based on:
Coastal Engineering Practice CommitteeCEM Preview
One Side Exposed to Waves
Coastal Engineering Practice CommitteeCEM Preview
Both Sides Exposed to Waves
Coastal Engineering Practice CommitteeCEM Preview
Geometric Design Aspects• Crest elevation and width• Concrete cap• Armor layer thickness• Primary layer bottom elevation• Toe berm• Structure head• Lee-side armor• Underlayers• Bedding/filter layer• Scour protection
Preliminary Design Phases
1. Structure geometry2. Evaluate construction
technique3. Evaluate design materials
Coastal Engineering Practice CommitteeCEM Preview
Crest width:
Armor layer thickness:
Riprap layer thickness:
(whichever is greatest)
Coastal Engineering Practice CommitteeCEM Preview
Overview of Armor Layer StabilityRubble-Mound Trunk and Head StabilityRiprap and Toe StabilityCross-Section DesignExample Problems
CEM Chapter VI-5-3 (Author: Hans F. Burcharth)CEM Chapter VI-7 (Author: David R. Basco)
Based on:
� Revetment StructureSame as runup and overtopping exmplThe CBBT Island Case Study
� Nearshore Breakwater StructureChesapeake Bay –Bay Ridge,MDCape Henry-Fort Story,VA
� Jetty Structure Oregon Inlet,NC
• Impermeable Revetment• Non-overtopping Waves• Armor Stone
Coastal Engineering Practice CommitteeCEM Preview
CBBT original design
• October 31,1991 Northeaster• The Great “Halloween Storm” of 1991• The Perfect Storm (Junger,1997)• The Storm of the Century (movie)
• The design wave height• The evolution of design waves• Impermeable revetments• Non-overtopping waves
• Table VI-6-4 Hudson formula• Table VI-6-5 Van der Meer (plunging)• Table VI-6-6 Van der Meer (surging)
• (a)Damage Curve Relations for VI-7-10• (b)Damage Curve Relations for VI-7-11
Coastal Engineering Practice CommitteeCEM Preview
• Nearshore breakwaters• Permeable• Submerged
SUMMARY: ARMORSUMMARY: ARMOR--LAYER STABILITYLAYER STABILITY
1. Hudson (1974) SPM (1984)1. Hudson (1974) SPM (1984)•• Limited applicabilityLimited applicability
-- ONLY permeable structuresONLY permeable structures-- ONLY nonONLY non--overtopping wave conditionsovertopping wave conditions
•• Factors not consideredFactors not considered-- Wave period, Wave period, TTpp
-- Variable structure permeability, PVariable structure permeability, P-- Damage level, SDamage level, S-- Storm duration (number of waves), tStorm duration (number of waves), tdd
SUMMARY: ARMORSUMMARY: ARMOR--LAYER STABILITYLAYER STABILITY
2. CEM (2000)2. CEM (2000)•• No limitationsNo limitations
-- Includes wave overtopping and Includes wave overtopping and submerged submerged condtionscondtions
-- Includes Includes TTpp, P, S and t, P, S and tdd factorsfactors•• Methods easy for EXCELMethods easy for EXCEL•• Includes partial safety factors for designIncludes partial safety factors for design
Use CEM (2000) methods to estimate armorUse CEM (2000) methods to estimate armor--layer stability.layer stability.