Typhoon is one of the common natural disasters in the Southeast coast of China.The huge waves induced by typhoon heavily threaten the construction and operation safety of bridges in the complex coastal area.One sea-crossing bridge under construction is located in the Fujian coastal area

which has a high risk of typhoon disaster

is taken as the example.The bridge site is under harsh marine environment and has many nearby islands and complex terrain.In order to study the characteristics of the extreme waves at the bridge site

60 hours of wave elevation data during Typhoon Dujuan were measured.The wave heights were obtained from the elevation data by

firstly

removing the errors and the trend of the tide and

secondly

reconstructing the missing data.The ratios between different statistic wave heights in this area were calculated by linear regression analysis

and were compared with the values given in"Code of Hydrology for Harbor and Waterway".Probability distributions of the wave height at the site were also discussed.The main conclusions include that

（1）the ratios of the statistic wave heights in this region agree well with those defined in the code.But more specifically

the ratios for each hour’s result show some randomness.（2）Gumbel distribution is well fit for the observed empirical wave height distribution.The study provides guidance and reference to the design and construction as well as disaster prevention of sea-crossing bridges under extreme waves.