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Chapter 5
Rubble Mound Structures
5.1 Introduction
Rubble mound structures are constructed for the construction seawalls and
groins for Coastal protection, revetments for bank protection, and training
walls for prévention of sand bar formation in a dominant littoral zone or
for navigational channels, spurs for training of rivers, breakwaters for the
formation harbour and Coastal protection through detached offshore or as
submerged breakwaters. The design of a rubble mound structure is quite
difficult compared to solid face structures as the interaction waves with
such structures is complex and are dictated by empirical formulae arrived
through physical modelling. Waves usually break over rubble mound structures and are exposed to non-stationary velocity and accélération fields in
particular during their run-up and rundown. The protection against waves
offered by these structures mainly dépend on its permeability and slope.
Flatter the slope, graduai is the dissipation of incident wave energy and
individual armour blocks that are needed for the structure to be stable
will be. Steeper slopes require larger size armour blocks for its stability.
The wave characteristics, tidal range, extreme events like storm surge control the design of rubble mound structures. Optimizing a rubble mound
structure that satisfy ail the requirements can only be achieved through
comprehensive physical model tests. The breakwaters, jetties, revetments,
seawalls, and spurs are mostly formed with a core of natural small size
natural rocks, sand filled in tubes (geo-tubes), or other suitable material
over which a layer of natural rocks, the weight of which is a function of the
prevailing wave climate are laid. For breakwaters, particularly in deeper
locations of high waves, an additional layer (top or primary layer) of artificial armour blocks of concrète are adopted. The rubble mound structures
adopted for Coastal protection or for formation of harbours are exposed
to waves propagating over different water levels, thus necessitating spécifie
designs or many times it may be a conventional one as per the site conditions and the purpose for which it is constructed. They are either designed
Chapter 5
Rubble Mound Structures
5.1 Introduction
Rubble mound structures are constructed for the construction seawalls and
groins for Coastal protection, revetments for bank protection, and training
walls for prévention of sand bar formation in a dominant littoral zone or
for navigational channels, spurs for training of rivers, breakwaters for the
formation harbour and Coastal protection through detached offshore or as
submerged breakwaters. The design of a rubble mound structure is quite
difficult compared to solid face structures as the interaction waves with
such structures is complex and are dictated by empirical formulae arrived
through physical modelling. Waves usually break over rubble mound structures and are exposed to non-stationary velocity and accélération fields in
particular during their run-up and rundown. The protection against waves
offered by these structures mainly dépend on its permeability and slope.
Flatter the slope, graduai is the dissipation of incident wave energy and
individual armour blocks that are needed for the structure to be stable
will be. Steeper slopes require larger size armour blocks for its stability.
The wave characteristics, tidal range, extreme events like storm surge control the design of rubble mound structures. Optimizing a rubble mound
structure that satisfy ail the requirements can only be achieved through
comprehensive physical model tests. The breakwaters, jetties, revetments,
seawalls, and spurs are mostly formed with a core of natural small size
natural rocks, sand filled in tubes (geo-tubes), or other suitable material
over which a layer of natural rocks, the weight of which is a function of the
prevailing wave climate are laid. For breakwaters, particularly in deeper
locations of high waves, an additional layer (top or primary layer) of artificial armour blocks of concrète are adopted. The rubble mound structures
adopted for Coastal protection or for formation of harbours are exposed
to waves propagating over different water levels, thus necessitating spécifie
designs or many times it may be a conventional one as per the site conditions and the purpose for which it is constructed. They are either designed