连续箱梁高架桥横向动力分析

本文提出了可以考虑箱形梁弯曲、扭转、畸变多种因素的梁－墩系统横向振动的动力分析模型。     

钻井过程中钻具吸附卡钻事故成因与处理技术

针对钻井过程中常遇的吸附卡钻事故，就其成因、产生条件及处理技术方法进行了较为详细的论述。结合工程实例对新研制的XS-1型解卡剂作用机理进行了分析、应用并提出了具体的操作规程和注意事项。     

卫星天线的单片机快速对星系统

使用GPS接收机模块得到卫星天线所在位置的经纬度,单片机模块进行数据处理得到对星所需要的方位角、仰角,与电子罗盘测得的天线的方位角、仰角进行比较得到其差值,并用液晶显示模块将其结果全部显示出来,指导天线操作人员实现快速、准确对星。     

鹿山大桥移动模架施工测量技术

鹿山大桥路线总长约2.422km,跨越约900m宽的富春江,水中和岸上引桥均采用预应力混凝土连续箱梁,跨径为31～50m,总长度为1018.1m,由两岸双幅25孔梁组成,主要采用移动模架进行施工。结合本桥的工程概况及特点,介绍了大桥的移动模架施工测量方法。     

大跨斜拉桥悬臂端钢箱梁上监测点高程测量新方法

在斜拉桥的主梁施工中,需要高精度测量悬臂端钢箱梁的高程。随着悬臂的增长,桥面的晃动越来越大,水准仪读数的难度也越来越大,甚至读不出数据;同时由于梁面上施工设备的影响,测量的难度很大,时间也很长。本文提出采用Leica TCA2003全站仪测量高差和水准仪测量工作基点高程相结合的方法,测量钢箱梁上监测点的高程,通过理论分析和对比实验证明了该方法的可行性。     

汶川地震庙子坪特大桥主桥箱梁开裂震害分析

2008年汶川地震中庙子坪特大桥主桥箱梁开裂严重,并在两个端部（过渡墩处）有较大的横向残余位移。为深入了解主梁开裂震害原因,选取桥址附近台站实测的八条强震动记录及常用El Centro等波作为输入,考虑箱梁施工过程及初始应力影响,通过时程分析进行数值模拟并与实际震害比较。结果表明:不同地震波输入下得到的箱梁高应力区与实际开裂区吻合较好,预示箱梁开裂震害不属于偶然现象。箱梁在主墩处、边跨和中跨合龙段区域处的顶板,边跨1/6~1/2及中跨1/4~3/4区域处的腹板,边跨和中跨合龙段及其相邻2~3个节段处的底板,在地震中易出现高拉或压应力区。地震过程中估计纵向预应力筋应力增加接近100MPa,横桥向挡块破坏降低了跨中箱梁的拉和压应力,对箱梁开裂震害有一定减轻作用。     

地震环境下钢筋混凝土箱梁复合受力特性分析

利用传统有限元分析法对地震环境下钢筋混凝土箱梁复合受力特性分析时,采用专家经验进行配筋,存在较强的主观意识,导致获取的复合受力特性分析结果存在偏差。根据以往的实验研究参数结合国家对混凝土桥梁参数的限制条件,构建地震环境下钢筋混凝土箱梁复合受力实验模型。设定实验模型尺寸,根据模型尺寸选择模型材料,采用圆钢与角钢搭建跨梁连续支座,融合反力架与千斤顶设计实验加载方案;根据方案中得出的配筋计算结果,获取地震环境下钢筋连续箱梁复合受力实验模型的科学配筋方案。实验结果表明,该实验模型可对地震环境下钢筋混凝土箱梁复合受力特性进行全面、准确分析。     

Cyclic tests of steel plate shear walls using box‐shape vertical boundary elements with or without infill concrete

The steel plate shear wall (SPSW) is an effective lateral force resisting system in which unstiffened steel infill plates are connected to the horizontal and vertical boundary elements (VBEs) on all sides of the plates. The boundary elements must be designed to resist the tension field force of the infill panels. When the VBEs are made from a steel box section, the flange of each box VBE connected with the infill panels can be pulled out‐of‐plane by significant panel forces, called pull‐out action. This study investigates capacity design methods for box VBEs in SPSWs. Simplified fixed beam and portal frame models aim to estimate the pull‐out responses of the flange of the box sections with and without infill concrete, respectively. In this study, cyclic tests of three full‐scale two‐story SPSWs using box VBEs with or without the infill concrete are conducted. Inelastic pushover analyses of the finite element models are conducted. The tests and analytical results confirm that the proposed design methods, which aimed to prevent the full yield of the flange under the pull‐out action, are applicable. Furthermore, the test and analytical results suggest that the initial yielding of the flange of box VBEs under the collective effects of the pull‐out action on the flange, the gravity load, and the sway action on the SPSW represents a local yielding. A strict prohibition of the initial yielding on the flange under the aforementioned collective effects is not recommended for pursuing a cost‐effective design. Copyright © 2017 John Wiley & Sons, Ltd.     

辽河盆地西部凹陷北部地区新生代断裂特征与圈闭类型

通过对辽河盆地西部凹陷北部地区构造特征研究,将新生代盆地划分为初始裂陷、伸展断陷、挤压拗陷3个演化阶段。新生代构造以张性断裂为主,兼具走滑和反转特征,其中,沙四、沙三期为伸展断裂系统,沙一、沙二至东营期为走滑断裂系统,馆陶期为挤压断裂系统。沙箱模拟实验证明,挤压反转构造受断层下盘施力方式控制,与基底走滑作用有关,伸展断裂控制的断鼻状构造和挤压背斜构造是高升斜坡带和牛心坨隆起带上较为有利的目标优选类型。     

Observations on shell growth and morphology of the bivalve Ruditapes philippinarum

The bivalve Ruditapes philippinarum is not only one of the main mollusc species in the west Pacific Ocean, but also one of the main species for aquaculture in China. Knowledge of growth of the R. philippinarum shell will improve our understanding of the shell as an environmental archive. It is also useful for the aquaculture of R. philippinarum. In this research, a hanging box culture method was introduced in the culture of R. philippinarum. The bivalves were cultured for 126 days, from March 31 to August 3, 2002. The average growth rates of shell width, height, and thickness were 0.069, 0.046, and 0.032 mm/d, respectively. The mean increase of average individual wet mass was 0.028 g/d. The largest growth rates of both shell and average individual wet mass occurred in June, indicating that water temperature and bivalve reproduction were 2 important factors. The shell morphology underwent significant changes with shell growth. The ratio of height to thickness (value of B/C) shifted 1.58 in the first 60 days to 1.54 in the last 30 days, which was resulted from the change in major shell growth direction. Periodic changes in the B/C ratio led to corrugated shell form, which could be used to determine the age of the shell.