Joints behaviour of through steel beam to composite column connection: Experimental study

The objective of this study is to categorize the failure modes; moment and rotation capacities; ductility; stiffness; joint classification; strain behaviour; and load transfer mechanism of steel beam through CFST column connections. Eight one-third scale composite joints were tested under static load up to failure. The key parameters comprise two η_Strength ratios; the effect of beam flange and web continuity inside the connection zone; and full cross-section continuity of steel beam. Moreover, the contribution of the connection component to the overall capacity of composite joints was determined. Results indicated that through beam connection could provide an ideal rigid joint. The absence of beam flange and the discontinuity of full beam cross-section made the connection component highly susceptible to fracture. In contrast, the presence of these details leads to higher ductile behaviour and prevent joint failure. The flange contribution to the moment and rotation capacities is significant, contrarily to the web contribution, which is negligible in value. The flange contribution to ductility coefficient is more dominated compared to web contribution. When strong column-weak beam criteria are followed, the continuity contribution to initial stiffness is more dominated. In contrast, the specimens that follow the weak column-strong beam criterion, the flange contribution to the initial stiffness has the major effect.     

装配式波纹钢板综合管廊连接节点抗震性能分析

为探究波纹钢板综合管廊在低周循环往复荷载作用下的滞回性能，以某波纹钢板综合管廊实际工程为依托，采用数值模拟与试验相结合的方法，研究管廊在横向、纵向、竖向共6种荷载工况下的抗震性能，以及法兰连接、法兰厚度、管廊壁厚（波纹钢板厚度）、螺栓位置等参数对结构滞回性能的影响。研究结果表明： 1）在低周循环往复荷载作用下，波纹钢板综合管廊塑性变形能力强，抗震性能良好；但管片拼装节点处是其薄弱位置，易发生脱开现象。 2）法兰对结构力学性能及滞回性能的影响显著，但法兰厚度改变对其影响较小。 3）环向法兰上螺栓的位置对结构纵向滞回性能影响较大，对其他方向滞回性能则几乎无影响。 4）波纹钢板厚度是影响结构抗震性能的关键因素。     

大直径盾构管片吊机系统故障分析及处理措施

针对京张铁路项目海瑞克盾构机S-1050在掘进过程中出现的管片吊机系统故障问题,主要从电路控制原理、S7-300PLC应用、机械等方面做详细阐述,并对主电路、PLC控制电路、管片吊机提升系统、吊机承重销轴、称重传感器等典型故障进行深入研究,探讨大直径盾构机管片吊机系统故障排查方法,尤其对管片运输吊机称重传感器和管片旋转吊机的关键电路部分进行综合分析,以便总结检修经验,在施工过程中准确、快速解决问题,提升盾构机掘进效率。     

一种多阵联合的拖线阵左右舷分辨方法

左右舷模糊一直是困扰拖曳线列阵声呐使用的关键技术,其制约了拖线阵声呐的使用效能。现有声呐系统装备的首端阵和舷侧阵均具有左右舷分辨能力,其与拖线阵声呐的信息互补性为拖线阵左右舷分辨提供了可能。文中提出一种多阵联合的拖线阵左右舷分辨方法,即利用舷侧阵和拖线阵公共频段的联合波束形成技术实现拖线阵的左右舷分辨,通过仿真分析验证了所提方法的有效性。结果表明,所提方法能够实现拖线阵左右舷分辨,平均分辨正确率不低于90%。     

带节点深水管道GSPU湿式保温管全尺寸模拟弯曲性能试验

文中介绍了全尺寸深水海底管道GSPU湿式保温涂层及节点SPU湿式保温涂层的模拟弯曲试验设备、方法、步骤及试验结果。通过试验前后表观观察及力学性能测试的对比分析,结果表明试验结果符合ISO 12736—2011附录B标准要求,节点及管体涂层经弯曲试验后与钢管之间剪切力也变化很小,充分说明节点及管体涂层的良好抗弯曲性能。     

一种接头管防绕流料仓漏斗在地连墙中的应用

本文提供一种能够确保地下连续墙接头管防绕流的料仓漏斗装置以及施工方法,适用于地下连续墙接缝施工,保证接缝施工质量,降低接头管被嵌固在墙体底部的风险,提高接缝抗渗漏能力。可在地连墙接头管施工中大力推广应用,装置新颖可靠、工艺成熟先进。     

Stress magnification effect of initial deformation on the notch stress field and fatigue strength of thin plate welded joints

Compared with thick plate welded joint, the welding joint of thin plate will produce initial deformation due to its low bending rigidity. The existence of initial deformation will cause the welded structure to produce secondary bending effect, which will produce greater stress magnification effect at the weld toe and seriously affect the fatigue strength of thin plate welded joints. Therefore, based on the correction formula of thick plate, considering the influence of initial deformation and geometric nonlinearity of thin plate, this paper deduces the stress magnification factor formula at the weld toe of T-shaped and cruciform specimens. The accuracy of the revised formula is further verified by comparing the notch stress calculated by the modified formula with the FE results. Finally, the modified formula is applied to the notch stress and fatigue evaluation of typical thin plate welded joints respectively. The results show that the proposed notch stress calculation formula can fully consider the stress amplification effect of thin plate structure, and can be used to quickly evaluate the notch stress field and fatigue strength of thin plate welded joints.     

管片钢筋骨架自动焊接技术的设计与应用

为解决当前盾构管片钢筋骨架焊接主要以人工焊接为主，存在劳动强度高、焊接环境差、焊接质量不稳定、焊接效率低下等问题，提出采用自动焊接的方式取代人工焊接。结合自动焊接技术在其他领域中的应用现状，就实现钢筋骨架自动焊接需要解决的具体问题进行分析，基于2步法，同时配套自动焊接生产线及工装夹具设计，即先完成钢筋网片自动焊接，再基于钢筋网片实现整个钢筋骨架的自动焊接。考虑到装备的经济性和灵活性，采用CO2气体保护焊焊接方式。结果表明： 1）钢筋骨架自动焊接系统具有对电力系统要求不高、产品焊接质量均匀可控、系统安全可靠等特点； 2）钢筋骨架自动焊接技术改变了钢筋骨架制作以人工焊接为主的传统加工方式，改善了工人的劳动环境和劳动强度，提高了盾构管片钢筋骨架的焊接质量。     

基于多波束点云的水下柱桩及桩间距高精度确定方法

受海水介质环境复杂、桩体倾斜以及测量误差大的影响,水下圆柱桩位置的高精度、低成本、高效率确定一直是港口工程建设中的一个难点。为此,提出了一种基于多波束点云的水下圆柱桩及桩间距高精度确定方法。该方法首先基于多波束测量实现桩体及海床点云数据低成本、高效获取。考虑桩体属性信息、点云法向量和高程等几何信息,利用一种综合阈值分割方法实现了桩体点云的有效提取。还提出了顾及桩体形态、测量误差的桩体中心位置综合确定方法,实现桩体相对位置和桩间距的高精度确定。该方法得到了实际工程验证,取得了优于5 cm的桩体相对位置和桩间距确定精度。     

螺栓锚固式桥梁伸缩装置技术及其应用

高速公路传统桥梁伸缩装置损坏后维修时间长,交通管制压力大。研发的螺栓锚固式桥梁伸缩装置技术,获得国家实用新型专利。该技术结构合理,施工更换方便快捷,使用寿命长;同时介绍了其安装实例。