斜拉桥鞍座锚固段拉索聚脲防腐耐磨层施工技术

新汴河大桥主桥B部分为独塔单索面预应力混凝土部分斜拉桥,该工程是徐州至明光高速公路的新材料、新技术应用工程,该桥塔上鞍座锚固段拉索采用了国内首次使用的钢绞线拉索专用防腐聚脲防护处理,该聚脲材料具有极佳的防腐性、韧性、拉伸强度、耐冲击性和耐磨性,从而提高了斜拉索的使用寿命。结合本工程施工实例,综合介绍该新型聚脲材料作为钢绞线拉索防腐耐磨层的施工方案和工艺流程,可为类似工程的应用及施工提供参考。     

大吨位箱梁单点顶推技术探讨

顶推法是顶推桥梁施工工法中常用的施工方法,但大吨位箱梁单点顶推施工国内较为少见.通过长沙湘府路湘江大桥跨京广铁路联主跨箱梁顶推施工实践,较为详细地总结了大吨位箱梁顸推施工中临时墩布置、滑道设置、纠偏限位控制、导梁安装及后锚点等结构体系的设置要点与施工过程中关键工序的控制要点.     

京沪高速铁路钢筋混凝土结构植筋锚固施工技术

结合京沪高铁钢筋混凝土结构植筋锚固施工实例,介绍了植筋锚固部位和设计要求,以及植筋锚固施工技术,为高速铁路由于设计变更、结构补强而总结出了一套成熟的、安全可靠的钢筋混凝土结构植筋锚固施工工艺.     

A New Technique of High-performance and Fast Tensioning Prestressed Anchorage CableEI北大核心

Research purposes: The large-span transition section tunnel of the Badaling Great Wall station on the Beijing-Zhangjiakou high-speed railway with the maximum excavation width of 32.7 m, and the largest excavation area of 494.4 m 2 , is the world's biggest traffic tunnel in the world with the largest excavation width and excavation area, which has difficult construction and high security risks. The initial support system of tunnel is mainly realized by prestressed bolt, prestressed cable and shotcrete. After test, anchor cable tension using the traditional anchor cable construction technology can't meet the design requirements, at the same time, it takes about 30 days to achieve prestressed tensioning. Therefore, we need to study the high-performance fast tensioning prestressed anchor cable technology, to effectively control surrounding rock deformation, to ensure the safety of construction, improve construction efficiency. Research conclusions:(1) The traditional anchor cable construction technology is adopted. The anchor cable tension value is mainly controlled by the grip force between the anchor rope and grouting body and the cohesive force between grouting body and surrounding rock. (2) The grip force between the anchor rope and the grouting body can be increased by about 2 times by increasing the "barb"; The cohesive force between the grouting body and the surrounding rock can be increased by 1.5 times by 6 ~ 7 MPa high-pressure grouting process. (3) The modified sulphoaluminate cement slurry can reach more than 30 MPa within 1 day of the slurry strength, so as to realize fast anchor cable tension within 1 day after grouting completion. (4)The research results can be used for reference in similar prestressed anchorage cable construction projects. © 2018, Editorial Department of Journal of Railway Engineering Society. All right reserved.     

压力型锚索锚固段应力分布规律及锚固段设计

根据Mindlin问题的位移解和弹性力学理论,基于变形协调假定,导出了压力型锚索锚固段粘结应力和轴力分布弹性理论解.采用岩质边坡条件下的参数,对锚固段应力分布进行了计算,总结了软岩条件下锚固段应力分布特征,并具体分析了锚固体半径对应力分布的影响,提出在设计中可以利用应力分布弹性理论解计算得到的应力分布曲线和应力峰值进行锚固段设计的思路,为压力型锚索的设计计算提供了一种参考依据.     

湛江海湾大桥锚拉板式索梁锚固区疲劳试验

为评估湛江海湾大桥锚拉板式索梁锚固结构关键构造细节的疲劳性能,对该结构进行了足尺模型疲劳试验.为指导疲劳试验,了解结构受力特性,用通用有限元软件ANSYS对结构进行了分析.结果表明,锚拉板与锚拉筒之间的连接焊缝下端部应力集中明显,最大主拉应力出现在该区域;在设计疲劳荷载作用下,该结构关键构造细节处均未发现疲劳裂纹,结构疲劳性能满足设计要求.     

轨枕板钢螺纹尼龙套管与硫磺锚固螺栓受力分析

车辆减速器轨枕板上的钢螺纹尼龙套管和硫磺锚固螺栓,在安装使用中,特别在施工新安装减速器时,常发生拔出并破坏混凝土轨枕板事故,造成不必要的损失。分析了钢螺纹尼龙套管和硫磺锚固螺栓在安装时所受到的拔力,以及安装时如何避免发生破坏轨枕板事故。     

大跨度斜拉桥索梁锚固区三维有限元仿真分析

采用不同建模方法,对大跨度斜拉桥索梁锚固结构—钢锚箱进行三维非线性有限元仿真分析,并将计算结果与钢锚箱静载模型试验结果相比较。结果表明,实体单元加接触单元法计算模型,即用实体单元模拟钢锚箱底部的锚垫板、用空间高阶壳单元模拟锚箱中其他钢构件及主梁、用非线性接触单元模拟锚垫板与承压板间不焊接但紧密压贴的关系,能够较真实、合理地反映钢锚箱的实际受力情况。钢锚箱虽然板件较多,但整体性能好,索力传递流畅,锚箱锚固顶、底板上2条焊缝传递索力,承压板与主梁焊缝主要传递抗弯作用力,因此要保证各板件接触、焊接良好,不能产生大的残余应力和残余变形。随着荷载的增长,钢锚箱高应力区应力增长速度减缓,部分低应力区应力增长加快,这对受载有利。仿真计算时,要注意壳单元角点局部位置可能出现应力计算失真。     

植入法嵌岩钢管桩桩端锚固技术

。章某化工园码头处基岩埋深浅、覆盖层薄,高桩梁板码头的桩基采用植入法嵌岩钢管桩文从设计和施工两方面对钢管桩桩端的锚固进行分析和研究,探讨出提高锚固能力的方法。     

某轮在文茨皮尔斯港锚地抗大风的几点启示

某轮在文茨皮尔斯港外锚地抗大风历时2天,经过全体船员的努力奋斗,终于保住了船舶和船员的安全,但留给我们的还有许多情况值得思考,以期在今后的抗大风操作中提醒广大船长和船员能做的更好,使船舶更安全。