Importance Of Seawall

1.0 Introduction

A sea wall is a form of coastal defense constructed where the sea, and associated coastal processes, impact directly upon the landforms of the coast. The purpose of a seawall is to protect areas of human habitation, conservation and leisure activities from the action of tides and waves. Seawalls may be constructed from a variety of materials, most commonly: reinforced concrete, boulders, steel, or gabions. Additional seawall construction materials may include: vinyl, wood, aluminium, fibreglass composite, and with large biodegrable sandbags made of jute and coir. A seawall works by reflecting incident wave energy back into the sea, thereby reducing the energy and erosion which the coastline would otherwise be subjected to.

Firstly, wave reflection induced by the wall may result in scour and subsequent lowering of the sand level of the fronting beach. Secondly, seawalls may accelerate erosion of adjacent, unprotected coastal areas because they affect the littoral drift process. The design and type of seawall that is appropriate depends on aspects specific to the location, including the surrounding erosion processes. There are three main types of seawalls: vertical, curved or stepped, and mounds. Project proposal is to construct a curved sea wall. Curved Seawalls help in breaking the waves and lessen the wave energy. The curved design of the seawalls adequately protects the base of the wall and prevents the waves from reaching the top of the wall. The concave structure of the seawall dissipates incident energy leading to low waves and reduced turbulence. But the biggest disadvantage of curved seawalls is that its design involves complex engineering and high costs. Besides, the deflected wave energy can rub against the material beneath the wall causing damage

In this way a full engineering description of each stratum can be obtained at the time the material is recovered in the ground. When in-situ testing is being done, supervision is equally important to ensure that the work is carried out with due care.

Ideally, the ground investigation should be conducted as an operation of discovery, utilizing a flexible step-by-step approach. It may often be possible, for example, to carry out a little amount of investigation using machine drug trial pits during the course of the site reconnaissance. Based on the results of this work, it will then be possible to plan the main phase of the ground investigation using the most appropriate and cost-effective methods. The extent and depth of the ground investigations will be determined by the geology of the site and the nature of the proposed sea wall construction. Where weak compressible materials are encountered, investigations should be taken deep enough to allow an estimate of consolidation settlement to be made. If bearing piles are thought to be a possibility the investigation should be continued until a suitable bearing stratum has been reached and shown to be of adequate thickness. In certain cases a