The Hong Kong–Zhuhai–Macao Bridge(HZMB)involved the installation of 120 mega-cylinders with a diameter of 22 m,weights up to 513 t,and penetration depths up to 33 m using an eight-vibratory hammer group.Due to the l...The Hong Kong–Zhuhai–Macao Bridge(HZMB)involved the installation of 120 mega-cylinders with a diameter of 22 m,weights up to 513 t,and penetration depths up to 33 m using an eight-vibratory hammer group.Due to the lack of engineering experience on the drivability of large-diameter cylinders under multiple vibratory hammers,predicting the penetration rate and time of steel cylinders is an open challenge that has a considerable impact on the construction control of the HZMB.In this study,the vibratory penetration of large-diameter steel cylinders in the HZMB is investigated based on geological surveys,field monitoring,and drivability analysis.The vibratory penetration rate,installation accuracy,and dynamic responses of the steel cylinders at both the eastern and western artificial islands are analyzed.The dynamic soil resistance has a great influence on the cylinder drivability.However,the current design methods for estimating the vibratory driving soil resistance are proven inaccurate without considering the scale effects.Therefore,a modified method with a normalized effective area ratio A_(r,eff)is proposed in this study to calculate the vibratory soil resistance for open-ended thin-wall cylinders under unplugged conditions.Considering the scale effects on the vibratory driving soil resistance,the proposed method leads to closer results to the measured data,providing a reference for future engineering practice.展开更多
针对目前EPCglobal ONS(Object Name Service)系统存在的信息容易被偷听、篡改、欺骗等威胁,提出一种基于DNSCurve协议和椭圆曲线加密机制的ONS系统来实现产品动态信息在查询过程中的安全性和隐私性,并通过实验验证此系统的安全性能,能...针对目前EPCglobal ONS(Object Name Service)系统存在的信息容易被偷听、篡改、欺骗等威胁,提出一种基于DNSCurve协议和椭圆曲线加密机制的ONS系统来实现产品动态信息在查询过程中的安全性和隐私性,并通过实验验证此系统的安全性能,能够抵御偷听、篡改、欺骗等攻击,有效地加强了ONS系统安全,对整个物联网的发展具有很重要的现实意义。展开更多
基金supported by the National Natural Science Foundation of China(52001267)Tianjin Port Engineering Institute Co.,Ltd.,and Eunsung O&C Offshore Marine and Construction(EUNSUNG19EG01).
文摘The Hong Kong–Zhuhai–Macao Bridge(HZMB)involved the installation of 120 mega-cylinders with a diameter of 22 m,weights up to 513 t,and penetration depths up to 33 m using an eight-vibratory hammer group.Due to the lack of engineering experience on the drivability of large-diameter cylinders under multiple vibratory hammers,predicting the penetration rate and time of steel cylinders is an open challenge that has a considerable impact on the construction control of the HZMB.In this study,the vibratory penetration of large-diameter steel cylinders in the HZMB is investigated based on geological surveys,field monitoring,and drivability analysis.The vibratory penetration rate,installation accuracy,and dynamic responses of the steel cylinders at both the eastern and western artificial islands are analyzed.The dynamic soil resistance has a great influence on the cylinder drivability.However,the current design methods for estimating the vibratory driving soil resistance are proven inaccurate without considering the scale effects.Therefore,a modified method with a normalized effective area ratio A_(r,eff)is proposed in this study to calculate the vibratory soil resistance for open-ended thin-wall cylinders under unplugged conditions.Considering the scale effects on the vibratory driving soil resistance,the proposed method leads to closer results to the measured data,providing a reference for future engineering practice.
文摘针对目前EPCglobal ONS(Object Name Service)系统存在的信息容易被偷听、篡改、欺骗等威胁,提出一种基于DNSCurve协议和椭圆曲线加密机制的ONS系统来实现产品动态信息在查询过程中的安全性和隐私性,并通过实验验证此系统的安全性能,能够抵御偷听、篡改、欺骗等攻击,有效地加强了ONS系统安全,对整个物联网的发展具有很重要的现实意义。
