Site Investigations

“Facts About Site Investigations” describes the many aspects of an investigation and why they are an integral part of all marine construction projects.

A site investigations is the first step toward a successful dredging project. Conversely, an inadequate site investigation is one of the most frequent causes of delay and of additional unexpected, unbudgeted costs. With modern techniques and computer-based site investigations, accurate preparation has become realistic and it will help define the design of the project and will limit, as much as possible, conflicts arising because of unforeseen conditions. For a “ground examination”, data collection of three aspects are recommended: geological and geotechnical evaluations; bathymetric surveys; and environmental assessments. This will answer some basic questions such as:
  • What types of soils and material are present?
  • Are these materials dredgeable?
  • What type of equipment and plant will be needed?
  • What will the wear and tear on plant be?
  • Is the stipulated budget feasible for the work to be carried out?
  Some large contractors have databases with the results of previous investigations. In those cases, especially for maintenance dredging, a desk study examining existing data may suffice. For most capital dredging projects, however, thorough inspection of the entire area is crucial. The most recent data is important because conditions change and earlier investigations may not wholly represent the present situation. For land reclamation projects, site investigations should include both the site of the dredging project, as well as the site of the borrow pit where fill is being extracted. In addition, other “above water” types of investigation could include knowledge of the frequency of marine traffic, obstructions such as debris, the location of outfalls, navigational markers or buoys, regulations specific to the particular site, and support and safety facilities such as air-sea rescue services, tugs, safe havens, and fuel and electricity supplies. In a broader view, the evaluation of noise and air quality, the presence of cultural or archaeological objects of value, and the impact of dredging on area activities, for instance, recreation are also important. The more knowledge the contractor, client and the public have, the better chances of a cost-effective operation with minimal risks. “Facts About Site Investigations” answers essential questions such as:
  • Why do site investigations matter?
  • When is a site investigation necessary?
  • When should a site investigation take place?
  • What constitutes a thorough site investigation?
  • What are geotechnical and geological evaluations?
  • How is geological data gathered?
  • What is a bathymetric survey?
  • What are environmental assessments?
  • What tools are used for site investigations?
  • Are there specific site investigation techniques for rock?
  • How many samples should be collected?
  • What are other aspects of a site investigation?
  • Who is responsible for the site investigation?
  • What are the advantages to a site investigation?
  • Who benefits from a good site investigation?