PART VII: APPLICATIONS 



91. Side-scan sonar results to date have shown that a variety of struc- 

 tures and bottom features can be successfully imaged with side-scan sonar. 

 These applications are categorized as follows: 



a. Providing quality control during and after construction. Side- 

 scan sonar could be used to monitor the extent of construction; 

 to explain cost overruns due to material loss or dredging out- 

 side of dredging limits; to document proper construction of 

 each layer, of any terraces or berms, and of the structure toe; 

 and to document uniformity of construction. 



b. Providing site reconnaissance to define existing structure and 

 site features. Side-scan sonar could be used to save time and 

 money on structure cross sections, bathymetric surveys, sedi- 

 ment sampling, and underwater inspections by identifying spe- 

 cific areas for quantitative survey (i.e., areas of structural 

 anomalies or deterioration, shoals, channels, bedrock outcrops, 

 disposal mounds, sediment interfaces, etc.). Areas of scour 

 and settling could also be documented using side-scan sonar. 

 Bedforms and features of the bottom sediments can be used to 

 interpret local processes. 



c. Locating underwater features. Side-scan sonar could be used to 

 locate navigation hazards prior to dredging and clearing opera- 

 tions; lost vessels prior to salvaging; and relict coastal 

 structures, pipelines, cables, and other items of interest in 

 planning, design, or construction. 



d. Monitoring changes to existing structures. Periodic comparison 

 of side-scan sonar records could be made to note failure at the 

 structure toe/bottom interface and major changes in the armor 

 cover layer. In addition, side-scan sonar can be used to 

 document scour around piers and structures and note areas of 

 shoaling in channels. 



92. The potential variety of applications is much wider than this 

 general list. Use of side-scan sonar on a particular project may provide the 

 user with detail of the structure and its setting beyond the original survey 

 scope. Other applications include any project where there is a need for rapid 

 qualitative information in support of planning, engineering, construction, or 

 maintenance. 



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