Floodwalls, Construction Materials and Land Surveying - Literature review Example

A flood wall is an artificial barrier that is built across a river or any other waterway that may rise above normal levels to protect the surrounding area from flooding side effects. Flood walls are mainly used in places where space is scarce and other methods, such as the construction of levees and dikes, would not be necessary due to interference with buildings or roads. Flood walls are majorly designed using prefabricated concrete materials and always have flood gates that provide passage, but are closed during flooding seasons to protect the surrounding land from flooding (Barr n.d.; Skinner et al 2001)Flood walls can be deployed by volunteers of emergency response teams in areas that are flood-prone (US Army Corps of Engineers 1995).

Traditionally, floodwalls are built using sandbags. Flood walls can be designed to provide both temporary and permanent protection against flooding, leading to the several types of floodwalls that are available depending on the type of protection intended (Skinner et al 2001).Types of floodwallsThe foregoing discussions explain the various types of floodwalls including gravity, cantilever, buttress, and counterfort types. In practice, the gravity and cantilever floodwalls are the more commonly used types.

Gravity floodwalls.From its name, this type of floodwall depends upon its weight for its stability. The structural stability of the gravity wall is attained by effective positioning of the mass of the wall, rather than considering the weight of the retained materials. The gravity wall resists overturning by the dead weight of the concrete and masonry construction. That is, it becomes too heavy to be overturned by the lateral flood load rocking on it. The frictional forces between the wall foot and the soil foundations prevent the sliding of the flood wall down the foundation.

The soil foundations' stability has to be maintained by making sure that the wall neither moves nor falls along surfaces of failure (Barr n.d.).Gravity walls are commonly used due to their advantages over other types. Gravity flood walls are appropriate for low walls or lightly loaded walls where the flood force expected is not too high. They are also relatively easy to construct and design. However, the major limitation of gravity floodwalls is that they require large volumes of material in their construction.

As the height of the gravity floodwall to be constructed increases, other types of floodwalls become cheaper.