Chapter 3: The design processct5308 Breakwaters and Closure DamsH.J. VerhagenApril 12, 2012                               ...
The design process    A design should combine:    • Functionality    • Technology (what is feasible)    • Environment (wha...
abstraction level• Macro level                             the system• Meso level                              a component...
Various levels of abstraction• design a world or regional concept for transport of  commodities• design regional or nation...
design phases•    initiative•    feasibility•    preliminary design•    final design•    detailed designApril 12, 2012    ...
Cyclic design                                 •   analysis                                 •   synthesis                  ...
Structural design                                 New Text• The structure should not fail:      Z = strength - load = R - ...
Problem !• In coastal engineering we have a problem with the  load.                        ρs Hs3                 M=      ...
Two cases1. It is a pure economic problem2. Also human lives and other non-monetary values are   included, like protection...
For breakwaters• Usually a pure economic problem• Balance between investments and maintenance has to  be found (see append...
Design storm and design life• Economic lifetime of a breakwater is in the order of 50 years• Decision makers therefore oft...
Better values• Life time 50 years• Probability of failure during lifetime 10%• Required storm frequency has to be:        ...
April 12, 2012   13
Upcoming SlideShare
Loading in...5
×

Breakwaters and closure dams: chapter 3

951

Published on

Published in: Education, Technology, Business
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total Views
951
On Slideshare
0
From Embeds
0
Number of Embeds
1
Actions
Shares
0
Downloads
58
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

Breakwaters and closure dams: chapter 3

  1. 1. Chapter 3: The design processct5308 Breakwaters and Closure DamsH.J. VerhagenApril 12, 2012 1Faculty of Civil Engineering and GeosciencesVermelding onderdeel organisatieSection Hydraulic Engineering
  2. 2. The design process A design should combine: • Functionality • Technology (what is feasible) • Environment (what is allowed or accepted) • Cost and Benefit (not only money) • Paperwork (drawing board) (could be replaced by virtual paperwork) • Matter (actual construction)April 12, 2012 2Vermelding onderdeel organisatie
  3. 3. abstraction level• Macro level the system• Meso level a component of the system• Micro level an element of one of the components Macro level Meso level Micro level 1a Harbour in global and Harbour layout Breakwater regional transport chain 1b Harbour layout Breakwater Crest block 2a Regional water Fresh water basin Closure dam for fresh management plan water basin 2b Fresh water basin Closure dam (location, Closing method cross section) 2c Decision to construct Dam in the Closing method north- the Delta plan Brouwershavense Gat gap 2d Dam in the Closing method north- Design of a caisson Brouwershavense Gat gapApril 12, 2012 3
  4. 4. Various levels of abstraction• design a world or regional concept for transport of commodities• design regional or national plans• design a national or provincial zoning policy• design an overall port with intermodal facilities• design a breakwater for such a port• design a quarry to provide stone (or find an alternative)• design the workshop for maintenance of the equipment of the quarryApril 12, 2012 4
  5. 5. design phases• initiative• feasibility• preliminary design• final design• detailed designApril 12, 2012 5
  6. 6. Cyclic design • analysis • synthesis • simulation • evaluation • decisionApril 12, 2012 6
  7. 7. Structural design New Text• The structure should not fail: Z = strength - load = R - S > 0• Simple case: cable in a crane strenght: R = A σ load: S=Mg Z = R - S = A σ - Mg Acrit = Mg/ σ Add safety factor: Acrit = γ Mg/ σ• Usually γ is given in professional codes and standards• For Breakwaters PIANC has issued values of γ• In case of high uncertainties a probabilistic approach can be followedApril 12, 2012 7
  8. 8. Problem !• In coastal engineering we have a problem with the load. ρs Hs3 M= KDΔ3 cot α• Load parameter: Hs• Strength parameters: ρs, Δ, M, KD, α• For strength parameters: Gauss distribution, small standard deviation• But there is no “average” Hs• We have to use a “design storm”April 12, 2012 8
  9. 9. Two cases1. It is a pure economic problem2. Also human lives and other non-monetary values are included, like protection of a museum or a religious siteApril 12, 2012 9
  10. 10. For breakwaters• Usually a pure economic problem• Balance between investments and maintenance has to be found (see appendix 7 in the book)• But this is often not done, because: • available budget for initial work • various sources of money for investment and maintenanceApril 12, 2012 10
  11. 11. Design storm and design life• Economic lifetime of a breakwater is in the order of 50 years• Decision makers therefore often suggest: “use for design a 1 in 50 years storm”• Probability of serious damage is Poisson distributed: p =− exp(− fTL ) • p = probability of occurrence on an event in period TL • TL = lifetime of construction • f = average frequency of the event per year ⎛ 1 ⎞ p =1 − exp ⎜ − 50 ⎟ =1 − exp(−1) = 0.632 ⎝ 50 ⎠• There is a probability of 63% that the construction will fail during lifetimeApril 12, 2012 11
  12. 12. Better values• Life time 50 years• Probability of failure during lifetime 10%• Required storm frequency has to be: 1 1 f =− ln(1 − p) =− ln(1 − 0.1) = 0.0021= 1 TL 50 474• So a 1/500 storm is a convenient valueApril 12, 2012 12
  13. 13. April 12, 2012 13
  1. A particular slide catching your eye?

    Clipping is a handy way to collect important slides you want to go back to later.

×