Storm Hazard Mitigation Structures References 681
Part C | 30
cantly increase our understanding of the physics in the
future.
30.3.3 Structural Design
The predominant material of construction for shoreline
stabilization structures is rock. Timber, steel, and concrete materials have been employed for groins but are
not considered here.
The structural design of rock structures is discussed
above (Sect. 30.2.3) for coastal armoring structures.
However, in many cases where headland breakwaters, near-shore breakwaters, and groins are built in
shallow water, only one rock size is employed as illustrated in Fig. 30.28. The crest elevation is above the
mean high water (MHW) tidal elevation but the structure is overtopped and often completely submerged
during storm surge events. The van der Meer formulations for overtopped and completely submerged
conditions should be employed. These structures are
highly permeable so that the permeability parameter,
P D 0:6.
30.4 Websites and Sea Level Rise Trends
30.4.1 Websites
The US Army Corps of Engineers, The Coastal
Engineering Manual (CEM): http://chl.erdc.usace.
army.mil/cem.
The Construction Industry Research and Information Association (CIRIA) The CIRIA/CUR/
CETMEF Rock Manual: http://www.ciria.org.
The EurOtop Team The Assessment Manual: http://
www.overtopping-manual.com.
The Calculation Tool: http://www.overtoppingmanual.com/calculation_tool.html.
30.4.2 Sea Level Rise Trends
Global climate change is real. The potential for accelerated, RSLR rates at most coastal locations poses a threat
to existing shore protection hard structures around the
world. Severe storms (low-pressure events and hurricanes) may occur more often to increase the frequency
of storm surges and shift the exceedance frequency
curves for high water elevations (Fig. 30.2). More severe storms may produce higher offshore wave heights.
Consequently, breaking waves near shore will be larger
due to deeper water depths closer to shore. These consequences of climate change and sea level rise on water
elevations and wave heights will produce larger stresses
on coastal structures. The exceedance probability for
the loads (water levels and wave heights) will increase
the probability of failure and resulting risk. In addition,
wave run-up and overtopping will increase to reduce the
functionality of the structures and add to the flooding
damage.
A review of the typical shore protection structures
shown in Fig. 30.4 and shoreline stabilization structures
presented in Fig. 30.16 reveals that rock structures are
most often the best alternative (lowest life-cycle costs)
for shore protection with hard structures. Rock structures can be more readily raised in crest elevation and
repaired when damaged than all the other types. Rock
structure crests can be elevated to keep up with potentially accelerating sea level rise rates to maintain
functionality for wave run-up and overtopping. And,
rock structure damage can be repaired to keep up with
larger waves producing more damage more often. The
resilience of the coastal shore protection effort can be
maintained with rock structures and hybrid structure
combinations (rubble mounds with frontal berms) will
be important in the future.
However, complete failure of the hard, shore protection system must always be considered in modern,
contemporary, coastal engineering design. See Kamphuis [30.17, Chapter 17] for a discussion of resilient
systems design that must also consider the social, political, and institutional constraints in the complete process
of resilient systems design.
References
30.1
CEM: The Coastal Engineering Manuel (US
Army Corps of Engineers, Engineering Research and Development Center, Vicksburg 2006,
2011)
30.2
Kuratorium für forschung im küsteningenieurwesen: EurOtop, wave overtopping of sea defences
and related sturctures: Assessment Manual, Küste
73, 1–178 (2007)
30.3
CIRIA/CUR/CETMEF: Rock Manual, 2007. The Use of
Rock in Hydraulic Engineering, 2nd edn. (CIRIA,
London 2007)
30.4
Y. Goda: Random Seas and Design of Maritime
Structures, 3rd edn. (World Scientific, Singapore
2010)
30.5
H. Oumeraci, A. Kortenhaus, W. Allsop, M. de Groot,
R. Crouch, H. Vrijling, H. Voortman: Probabilistic
Part C | 30
cantly increase our understanding of the physics in the
future.
30.3.3 Structural Design
The predominant material of construction for shoreline
stabilization structures is rock. Timber, steel, and concrete materials have been employed for groins but are
not considered here.
The structural design of rock structures is discussed
above (Sect. 30.2.3) for coastal armoring structures.
However, in many cases where headland breakwaters, near-shore breakwaters, and groins are built in
shallow water, only one rock size is employed as illustrated in Fig. 30.28. The crest elevation is above the
mean high water (MHW) tidal elevation but the structure is overtopped and often completely submerged
during storm surge events. The van der Meer formulations for overtopped and completely submerged
conditions should be employed. These structures are
highly permeable so that the permeability parameter,
P D 0:6.
30.4 Websites and Sea Level Rise Trends
30.4.1 Websites
The US Army Corps of Engineers, The Coastal
Engineering Manual (CEM): http://chl.erdc.usace.
army.mil/cem.
The Construction Industry Research and Information Association (CIRIA) The CIRIA/CUR/
CETMEF Rock Manual: http://www.ciria.org.
The EurOtop Team The Assessment Manual: http://
www.overtopping-manual.com.
The Calculation Tool: http://www.overtoppingmanual.com/calculation_tool.html.
30.4.2 Sea Level Rise Trends
Global climate change is real. The potential for accelerated, RSLR rates at most coastal locations poses a threat
to existing shore protection hard structures around the
world. Severe storms (low-pressure events and hurricanes) may occur more often to increase the frequency
of storm surges and shift the exceedance frequency
curves for high water elevations (Fig. 30.2). More severe storms may produce higher offshore wave heights.
Consequently, breaking waves near shore will be larger
due to deeper water depths closer to shore. These consequences of climate change and sea level rise on water
elevations and wave heights will produce larger stresses
on coastal structures. The exceedance probability for
the loads (water levels and wave heights) will increase
the probability of failure and resulting risk. In addition,
wave run-up and overtopping will increase to reduce the
functionality of the structures and add to the flooding
damage.
A review of the typical shore protection structures
shown in Fig. 30.4 and shoreline stabilization structures
presented in Fig. 30.16 reveals that rock structures are
most often the best alternative (lowest life-cycle costs)
for shore protection with hard structures. Rock structures can be more readily raised in crest elevation and
repaired when damaged than all the other types. Rock
structure crests can be elevated to keep up with potentially accelerating sea level rise rates to maintain
functionality for wave run-up and overtopping. And,
rock structure damage can be repaired to keep up with
larger waves producing more damage more often. The
resilience of the coastal shore protection effort can be
maintained with rock structures and hybrid structure
combinations (rubble mounds with frontal berms) will
be important in the future.
However, complete failure of the hard, shore protection system must always be considered in modern,
contemporary, coastal engineering design. See Kamphuis [30.17, Chapter 17] for a discussion of resilient
systems design that must also consider the social, political, and institutional constraints in the complete process
of resilient systems design.
References
30.1
CEM: The Coastal Engineering Manuel (US
Army Corps of Engineers, Engineering Research and Development Center, Vicksburg 2006,
2011)
30.2
Kuratorium für forschung im küsteningenieurwesen: EurOtop, wave overtopping of sea defences
and related sturctures: Assessment Manual, Küste
73, 1–178 (2007)
30.3
CIRIA/CUR/CETMEF: Rock Manual, 2007. The Use of
Rock in Hydraulic Engineering, 2nd edn. (CIRIA,
London 2007)
30.4
Y. Goda: Random Seas and Design of Maritime
Structures, 3rd edn. (World Scientific, Singapore
2010)
30.5
H. Oumeraci, A. Kortenhaus, W. Allsop, M. de Groot,
R. Crouch, H. Vrijling, H. Voortman: Probabilistic