开敞海域淤泥质浅滩深挖槽航道边坡研究

安全、经济地确定航道边坡坡度意义重大.依托连云港徐圩港区5 万-10万吨级航道工程,在现场观测分析的基础上,从岩土整体稳定角度和波浪动力角度,研究提出了开敞海域淤泥质浅滩深挖槽航道边坡设计方法.结果表明,在连云港徐圩航道区域,航道边坡坡比采用1 ： 7 是基本稳定的;选用无侧限抗压试验指标作为航道边坡岩土稳定分析计算参数,提升了岩土整体稳定分析手段在航道边坡设计的作用;首次采用波浪摩阻流速研究了不同浪级、波向、坡度、航道等级条件下波浪动力对航道稳定性的影响.

环抱式防波堤口门航道横流三维特性研究

环抱式防波堤口门易出现较大横流,且三维特性明显。针对连云港主港区深水航道,建立三维潮流数学模型,并用现场航槽实测资料进行验证,在此基础上计算分析了不同潮差条件下口门段进港航道横流的三维特性。研究结果表明:最大横流约出现在高潮位前1.5 h,自表层至底层相继出现,且表、底层出现时刻仅相差0.5 h;因航道边坡较小,最大横流时未见水流分离现象,航槽底部没有反向流;各层最大横流值均与涨潮潮差有关,且相关程度高;航道内最大横流垂向分布梯度随潮差增加略有增大。

GaAs垂直结构PIN二极管限幅器

基于垂直结构GaAs PIN二极管的工艺技术开发,在GaAs PHEMT生产线上开发研制了GaAs PIN二极管限幅器单片集成电路。针对不同频段的单片电路采用了不同的材料结构参数设计。工艺中采用先进的深挖槽技术,严格控制横向钻蚀问题,制作出了限幅水平40 mW、最大承受功率5 W的多个频段GaAs限幅器单片电路,成品率达到95%以上。GaAs垂直结构PIN二极管工艺对GaAs PIN二极管大功率开关、限幅器等GaAs MMIC的发展具有重大意义。

Stability of long trench in soft soils by bentonite-water slurry

A series of centrifuge model tests exploring the effects of different types of slurry on long-trench stability in soft clay were conducted. The influence of groundwater conditions relative to trench stability was examined by constructing long trenches using different slurries. The soil deformation and surface settlement induced by the excavation of the trench are found to be closely related to slurry type and excavation depth of the long trench. Increasing the bentonite concentration of the slurry has beneficial effects on stability: 1) larger particles can improve local and global stability in cases where filter cakes do not form, and 2) larger viscosity can promote filter cake formation on the walls of long trenches excavated in soft clay and enhance their stability.