With the constant threat from natural disasters like tsunamis and rising sea levels, sea wall design has also improved to help reduce the devastating force these natural disasters can unleash on coastal communities.
Changes that have been noted to make the biggest difference are:
- Shape – with the help of simulators that help imitate the way a wave acts it has been noted that strait walls are subjected to more force from the waves. This leads to the weakening and destruction of the wall over time. The shape of the sea wall along the coast line as well as the shape of the sea wall itself makes a difference to how much protection it can offer.
- Construction Material – soil was mostly used in the past due to its easy availability but it has been noted to be a rather weak form of wall building material. A mixer of soil and boulders has been proven to be a stronger base material with the soil anchoring the bolder in place while the rocks take the brunt of the force.
- Sea wall skins – above the wall itself a firm covering of jagged rocks should be provided. Jagged (odd shaped rocks) or cement blocks provide absorb and cushion the wave’s force thus slowing it down rapidly as the wave tries to compensate filling the gapes in between the rocks before moving along.
Sea wall stability mainly depends on back wall fill, since the back wall fill is what holds the wall together during storms. If the back fill on the wall is less than the strength of the wall is greatly reduced and vice versa. The foundation beneath the wall itself should also be strong and this can be done by digging a deep trench before beginning the fill.
Confession of the filling material also ensures immediate strength since loose soil will be easily washed away. The trench also breaks the layer between the ground level and the trench attaching the sea wall to the ground. The mixer of soil, rock boulder and cement (if possible) should be used starting from the foundation trench working its way up to the sea wall.
These methods can be used to cover long distance with shorter residential areas enforcing other designs. Sea wall designs that splash back the wave in to itself are also in use were high tides sometimes send rough waves. The splash back causes a counter reaction force working against itself to reduce its strength thus reducing its high and keeping the water at bay.
Sea wall design can only help reduce the damage done by rough waves since it is not possible to prepare for rare waves that tower 100-150‘high for which no sea wall can offer protection. It is in the interest of engineers that they should improve sea wall design so as to reduce destruction caused by sea wall construction methods that are out dated and termed not effective in modern engineering.
Sea Wall Design,