Thewavetransmissioncharacteristicsandwaveinducedpressuresontwinplatebreakwaterareinvestigatedexperimentallyinregularandrandomwaves.Atotaloftwentypressuretransducersarefixedonfoursurfacesoftwinplatetomeasurethewaveinduceddynamicpressures.Thespatialdistributionofdynamicwavepressureisgivenalongthesurfaceofthetwinplate.Theupliftwaveforceobtainedbyintegratingthehydrodynamicpressurealongthestructureispresented.DiscussedaretheinfluenceofdifferentincidentwaveparametersincludingtherelativeplatewidthB/L,relativewaveheight/iHaandrelativesubmergencedepths/aonthenon-dimensionaldynamicwavepressuresandtotalwaveforces.Fromtheinvestigation,itisfoundthattheoptimumtransmissioncoefficient,tKoccursaroundB/L0.41~0.43,andthetwinplatebreakwaterismoreeffectiveindifferentwaterdepths.Themaximumofpressureratiodecreasesfrom1.8to1.1whentherelativesubmergencedepthoftopplateisincreasedfrom0.8to+0.8.
