Reliability Assessment of Breakwaters

In this report, several level II reliability techniques are discussed and applied to breakwater design. Using these methods, the reliability and reliability index are determined for the dominant performance functions of a breakwater including stone and concrete armor stability, concrete armor structural response, runup, and overflopping. The methods include Taylor series finite difference (TSFD) methods, which are shown to be easily computed using a handheld calculator or spreadsheet. The TSFD method is shown to yield reasonable accuracy for preliminary comparison of various alternatives. An invariant iterative TSFD method and associated FORTRAN program are shown, which provide an improved approximation to the reliability for design and evaluation purposes.