简介：Theresultsofastudyonthekeytechnologyofusingshellsand,akindofseasand,asbackfillforseareclamationaredescribedbriefly.Laboratorytestsshowthatthephysicalandmechanicalpropertiesofshellsandareasgoodasnormalquartzsand.Basedonthechemicaltestanddurabilitytestofshellsanditcouldbeconcludedthattheinfluenceofcorrosionofshellsandbyacidrainandseawatermightbeignoredintheevaluationofthesafetyanddurabilityoftheengineeringproject.Theresultsoffieldimprovementtestsshowthatthebearingcapacityofshellsandbackfillfoundationismorethan200kPaaftervibroflotationimprovementordynamiccompactionimprovement.Theshellsandisagoodbackfillmaterialforseareclamation.

简介：-Thispapercarriesouttheanalysisofmechanicsofagripsystemofthree-key-boardhydraulictongsdevelopedforoffshoreoilpipelineswhichhasbeensuccessfullyusedinoilfieldsinChina.Themainimprovementofthissystemisthataleverframestructureisusedinthestructuraldesign,whichreducesgreatlythestressesofthemajorcomponentsoftheoilpipetongs.Theoreticalanalysisandnumericalcalcu-lationbasedonthirteenbasicequationsdevelopedshowthattheteethboardofthetongsisnoteasytoslipasfrequentlyhappenstoothersystemsandisofhigherreliability.