Unclassified 



20. Continued 



estimate of the condition and the extent of required maintenance is obtained, guarantees 

 that the inspection will gather information that can be analyzed in a manner consistent with 

 standard statistical practices. The procedures presented in this report yield results that can 

 be relied upon for a given confidence level and accuracy requirement. The criteria presented 

 in this report provide a scientific method for specifying the number of elements to be 

 sampled for each waterfront facility. Data obtained using these criteria can be compared 

 to each other with proven correlation procedures to indicate trends in deterioration rates 

 and allow more accurate projections of maintenance and repair requirements. 



Library Card 



Naval Civil Engineering Laboratory 



SAMPLING CRITERIA AND PROCEDURES FOR UNDERWATER 

 INSPECTION OF WATERFRONT FACILITIES (Final), by R.L. Bracken 

 TN-1762 98ppillus December 1986 Unclassified 



1. Inspection criteria 



2. Statistical analysis 



I. YF60.534.091.01.202 



Sampling criteria have been developed for planning and executing an underwater inspection 

 of waterfront structures. The proposed sampling criteria use statistical sampling methods and in- 

 ferences. Statistical sampling provides an objective method for determining the sample size (for 

 variables and for proportions), for estimating population parameters for a desired confidence level 

 and precision, and for evaluating the cost tradeoffs based upon a desired confidence level and pre- 

 cision. The scientific approach to sampling, where an estimate of the condition and the extent of 

 required maintenance is obtained, guarantees that the inspection will gather information that can 

 be analyzed in a manner consistent with standard statistical practices. The procedures presented 

 in this report yield results that can be relied upon for a given confidence level and accuracy re- 

 quirement. The criteria presented in this report provide a scientific method for specifying the 

 number of elements to be sampled for each waterfront facility. Data obtained using these criteria 

 can be compared to each other with proven correlation procedures to indicate trends in deteriora- 

 tion rates and allow more accurate projections of maintenance and repair requirements. 



Unclassified 



