110
Coastal Engineering: Theory and Practice
Jetties
Jetties are usually constructed perpendicular to the shore; it can be effectively used inside harbor basins for transfer of cargo. It can be broadly
classified as open jetty (piled) or closed/solid jetty (closed walls with earth
fill). The solid jetties can influence the shoreline dynamics similar to that
of a groin. Figure 4.8 shows a typical layout of jetty. It demonstrates that
this is longshore drift dominated coast that has lead to the advancement of
the shoreline on the updrift, whereas, the downdrift side is protected by a
groin field as a countermeasure for érosion. Groin is also spelt as groynes.
Approach channel
Breakwateç
Up drift
( accretion)
■ “
7 Direction of
j prédominant
’ littoral drift
Direction of
Wave crest
Fig. 4.8 Layout of a jetty.
Revetments
Revetments are structures deployed primarily to improve the stability of
the sloping surfaces along the shore. It is a sought after durable and environment friendly érosion protection System for berms, slopes, riverbanks
and shorelines. The revetments can be made up rubble stones, concrète
blocks with good interlocking capacity or even geosynthetics and geosystems. Figure 4.9 shows a typical cross-section of quarry stone revetment,
which is quite easy to construct. Interlocking concrète blocks of different
shapes also exist for forming the revetment.
Coastal Engineering: Theory and Practice
Jetties
Jetties are usually constructed perpendicular to the shore; it can be effectively used inside harbor basins for transfer of cargo. It can be broadly
classified as open jetty (piled) or closed/solid jetty (closed walls with earth
fill). The solid jetties can influence the shoreline dynamics similar to that
of a groin. Figure 4.8 shows a typical layout of jetty. It demonstrates that
this is longshore drift dominated coast that has lead to the advancement of
the shoreline on the updrift, whereas, the downdrift side is protected by a
groin field as a countermeasure for érosion. Groin is also spelt as groynes.
Approach channel
Breakwateç
Up drift
( accretion)
■ “
7 Direction of
j prédominant
’ littoral drift
Direction of
Wave crest
Fig. 4.8 Layout of a jetty.
Revetments
Revetments are structures deployed primarily to improve the stability of
the sloping surfaces along the shore. It is a sought after durable and environment friendly érosion protection System for berms, slopes, riverbanks
and shorelines. The revetments can be made up rubble stones, concrète
blocks with good interlocking capacity or even geosynthetics and geosystems. Figure 4.9 shows a typical cross-section of quarry stone revetment,
which is quite easy to construct. Interlocking concrète blocks of different
shapes also exist for forming the revetment.