200
CHAPTER 5. COASTAL STRUCTURE MOD
between tests raise the question about which result best represents
prototype. Here the experience of the model engineer comes into plæ
the differences are limited, the conservative result can be chosen. L
differences in stability warrant further investigation.
Usual data collection during stability testing includes recording \
data and recording changes to the rubble-mound profile. Wave ga
often are located in deeper water near the wave board and in shallow w
immediately in front of the structure. Gauge arrays might be use
extract the incident and reflected wave spectra using the methods give
Chapter 7.
Profile structure changes traditionally are measured using a soun
rod technique. Hudson (1959) recorded rubble-mound structure pre
using a sounding rod fitted with a foot made of a circular plate havin
area of one-half the average diameter of the armor stones.
Besides wave and structure profile data, auxiliary measurements n
be needed to document such phenomena as wave overtopping and ti
mission, flows and pressures within the structure, flow kinematics nea
toe and slope of the structure, and stresses within individual armor u
Defining Damage in Rubble-Mound Models
Damage occurs to rubble-mound structures when individual armor
on the structure are dislodged which can lead to further unraveling c
structure or loss of underlayer materials. Armor stone can usually tol
rocking without loss of armor layer integrity. However, if the armor
consists of slender artificial concrete units, then even rocking in plao
cause breakage of the units into smaller pieces which are more easil
moved by waves. (Simulation of armor layer damage due to breakz
discussed in the section following this one.) Owen and Briggs (1985) i
that failure can also involve loss of armor on the structure’s lee side d
wave overtopping, displacement of the structure’s crown, slumping (
rubble-mound, or fluidization of the armor layer.
1 he armor size distribution and contact with neighboring units
great influence on the stability of individual armor units. Therefore,
age should not be expected to be uniformly distributed across th<
section of the model, but instead damage will occur in spots (Tprum,
1979).
I wo methods are commonly used for quantifying damage in n
mound structure models: counting the number of individual armor
that have been dislodged, or determining the volumetric change in
where armor units have been displaced.
I he method of counting displaced armor units requires some v
CHAPTER 5. COASTAL STRUCTURE MOD
between tests raise the question about which result best represents
prototype. Here the experience of the model engineer comes into plæ
the differences are limited, the conservative result can be chosen. L
differences in stability warrant further investigation.
Usual data collection during stability testing includes recording \
data and recording changes to the rubble-mound profile. Wave ga
often are located in deeper water near the wave board and in shallow w
immediately in front of the structure. Gauge arrays might be use
extract the incident and reflected wave spectra using the methods give
Chapter 7.
Profile structure changes traditionally are measured using a soun
rod technique. Hudson (1959) recorded rubble-mound structure pre
using a sounding rod fitted with a foot made of a circular plate havin
area of one-half the average diameter of the armor stones.
Besides wave and structure profile data, auxiliary measurements n
be needed to document such phenomena as wave overtopping and ti
mission, flows and pressures within the structure, flow kinematics nea
toe and slope of the structure, and stresses within individual armor u
Defining Damage in Rubble-Mound Models
Damage occurs to rubble-mound structures when individual armor
on the structure are dislodged which can lead to further unraveling c
structure or loss of underlayer materials. Armor stone can usually tol
rocking without loss of armor layer integrity. However, if the armor
consists of slender artificial concrete units, then even rocking in plao
cause breakage of the units into smaller pieces which are more easil
moved by waves. (Simulation of armor layer damage due to breakz
discussed in the section following this one.) Owen and Briggs (1985) i
that failure can also involve loss of armor on the structure’s lee side d
wave overtopping, displacement of the structure’s crown, slumping (
rubble-mound, or fluidization of the armor layer.
1 he armor size distribution and contact with neighboring units
great influence on the stability of individual armor units. Therefore,
age should not be expected to be uniformly distributed across th<
section of the model, but instead damage will occur in spots (Tprum,
1979).
I wo methods are commonly used for quantifying damage in n
mound structure models: counting the number of individual armor
that have been dislodged, or determining the volumetric change in
where armor units have been displaced.
I he method of counting displaced armor units requires some v