192
CHAPTER 5. COASTAL STRUCTURE MODEL
designed and operated 3-d physical model, unless “the owner and engine
are in a position knowingly to take large risks.
5.2.4 Rubble-Mound Model Scale Selection
Scale selection for all models of coastal structures involves a compromis
between the desire to model at as large a scale as possible to avoid potenti;
scale effects and the economics of conducting tests at smaller scales.
Within the acceptable scale range for rubble-mound structure test;
scale selection decisions are influenced by practical considerations, such i
size of available model armor units, water depth of available wave tanks an
basins, and wave generating capability. Sometimes the model engineer wi
model several different prototype conditions using one set of model arme
units by simply changing the length scale and altering the model wat<
depth and wave conditions accordingly. The range of length scales is the
dictated by the wave flume dimensions and wave generation capability.
Based on successes of the past, Hudson, et al. (1979) suggested that th
appropriate length scale range for rubble-mound stability tests is betwee
1:5 and 1:70. The majority of tests conducted by Hudson at the Waterway
Experiment Station were at scales between 1:40 and 1:50.
Oumeraci (1984) stated that rubble-mound structure models have line:
scales ranging between 1:10 and 1:80, with 1:50 being the most commoi
Jensen and Klinting (1983) give a somewhat larger scale of 1:30 as beir
the most common scale for model rubble-mound breakwaters.
5.2.5
Rubble-Mound Structure Modeling Procedures
Physical model tests of rubble-mound structures primarily are used to eva
uate how well the armor layers stand up to severe wave attacks anticipate
in the prototype. In order to make this evaluation, the model engineer mu;
1. Assure that the rubble-mound as constructed in the model
is representative of what is (or will be) constructed in the
prototype.
2. Operate the model in the most appropriate manner.
3. Utilize a reliable and consistent method of evaluating damage to the structure.
Many laboratories throughout the world have been conducting rubbl
mound stability tests for decades, and in the process, have developed ted
niques and procedures that often become “standard practice” for all sul
sequent studies. For example, Owen and Allsop (1983) described typic
CHAPTER 5. COASTAL STRUCTURE MODEL
designed and operated 3-d physical model, unless “the owner and engine
are in a position knowingly to take large risks.
5.2.4 Rubble-Mound Model Scale Selection
Scale selection for all models of coastal structures involves a compromis
between the desire to model at as large a scale as possible to avoid potenti;
scale effects and the economics of conducting tests at smaller scales.
Within the acceptable scale range for rubble-mound structure test;
scale selection decisions are influenced by practical considerations, such i
size of available model armor units, water depth of available wave tanks an
basins, and wave generating capability. Sometimes the model engineer wi
model several different prototype conditions using one set of model arme
units by simply changing the length scale and altering the model wat<
depth and wave conditions accordingly. The range of length scales is the
dictated by the wave flume dimensions and wave generation capability.
Based on successes of the past, Hudson, et al. (1979) suggested that th
appropriate length scale range for rubble-mound stability tests is betwee
1:5 and 1:70. The majority of tests conducted by Hudson at the Waterway
Experiment Station were at scales between 1:40 and 1:50.
Oumeraci (1984) stated that rubble-mound structure models have line:
scales ranging between 1:10 and 1:80, with 1:50 being the most commoi
Jensen and Klinting (1983) give a somewhat larger scale of 1:30 as beir
the most common scale for model rubble-mound breakwaters.
5.2.5
Rubble-Mound Structure Modeling Procedures
Physical model tests of rubble-mound structures primarily are used to eva
uate how well the armor layers stand up to severe wave attacks anticipate
in the prototype. In order to make this evaluation, the model engineer mu;
1. Assure that the rubble-mound as constructed in the model
is representative of what is (or will be) constructed in the
prototype.
2. Operate the model in the most appropriate manner.
3. Utilize a reliable and consistent method of evaluating damage to the structure.
Many laboratories throughout the world have been conducting rubbl
mound stability tests for decades, and in the process, have developed ted
niques and procedures that often become “standard practice” for all sul
sequent studies. For example, Owen and Allsop (1983) described typic