水下接触和近场爆炸作用下沉箱码头的毁伤特性

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中图分类号：0383.1 国标学科代码：13035 文献标志码：A

Abstract：Toinvestigatethedamage mechanismandloadcharacteristicsofcaissonwharfunderunderwatercontactandnearfieldexplosion，ahigh-fidelitynumericalmodelwasconductedbasedonthescaledmodeltestsofcaisonwharfandverified bycomparingthesimulationresultswiththeexperimentaldata.Thepropagationandatenuationcharacteristicsofshockwaves inside the caisson，partition wals，，and intermal backfillsoil were analyzed.The destructionprocessand typical damage mechanisms of thecaisson wharf were analyzedbycomparing Holmquist-Johnson-Cook constitutive model damage contour maps with experimental results.The results shows that the damage areas and characteristics ofthe caison wharf are largely consistent underboth underwater contact and near-field explosion.Theprimary damage areas are blast-facing walland deck slab.The blast-facing wallexhibitscratering and breaching phenomena，whileof the deck slab shows transverse ful-length cracksatrench-slabconections，ongitudinalacksandblowoffhesidewalsanditeralparitionsofthecissonharf sustain elatively minor damage.Shock wave within thecaison subjected tounderwater contactand near-fieldexplosions undergo reflection andtransmissionatthe interfaces betweenthe partitions and filings within thecompartments.The blastfacingwallandsidewallsofthewharfaresubjectedtoshockloads.The transmitedcompressivewavesacross thetransverse bulkheads and blast-resistant back walsexhibited amplification compared tothe incident waves，whereas atenuation was observedasthewavestraversedthesand-filledcompartments.Numericalsimulationresultsrevealedthat theshockwaveload within thecaisson undergoes adecayrate thattransitions fromrapid to gradual.Damage characteristicsof caison wharf is primarilyshaped during the underwater explosion shockwave phase. Neglecting large-scale macroscopic movements such as upliftandscattering postpanel failure，thedamage formation timeslightly exceeds twicetheshockwave propagationduration through the structure.

Keywords：underwater contact explosion; underwater near-field explosion;caisson wharf;damage effect; damage mechanism; shock wave propagation

水下爆炸相较于空中爆炸，具有毁伤作用更强、破坏机理更复杂、毁伤部位更隐蔽和毁伤程度难以探查等特点，是沉箱码头面临的主要威胁之一。（剩余16494字）