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大汶溪大桥是一座双塔斜拉桥,施工过程中采用了塔梁同步施工技术。通过严谨的测量监控,大桥施工过程中塔柱、主梁和斜拉索一直处于动态三角平衡状态。在塔梁同步施工过程中,采取测量控制修正了施工各阶段的应力、线型、索力和各种施工误差,有效地解决了主塔在不均匀水平力作用下塔柱顺直施工的问题,使大汶溪大桥在成桥后整体内力和线型能够满足设计要求。 相似文献
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《Planning》2015,(13)
武汉鹦鹉洲长江大桥设计为三塔四跨悬索桥,其1号塔位于长江汉阳岸边坡坡脚,门框式结构,采用了高效快速施工方法施工成型。底节塔柱与塔座同步浇筑,塔柱采用无劲性骨架法施工,配备6m高大节段液压爬模结构,塔柱下横梁采用钢管支架法与塔柱并行施工,上横梁采用牛腿支架法与塔柱同步施工,并在地面进行对拉试验取代高空支架预压施工。通过设计和施工相结合,做到了施工过程模块化和简单化,实现了塔柱快速施工,探索了塔柱施工新方法。 相似文献
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结合温州市七都大桥北汊桥工程主通航孔索塔的施工,对独柱式变截面长圆形索塔的施工关键技术进行了研究。鉴于主塔结构形式,经分析后决定,下塔柱施工采用整体定型钢模板模架一体化施工工艺,中塔柱和上塔柱采用液压爬模施工工艺,利用定型筋性骨架进行钢筋的安装和固定,钢锚梁、钢牛腿及索导管于塔侧平台上拼装、整体吊装定位,主塔混凝土采用汽车泵和固定泵配合浇筑的方式,并在主塔施工过程中,严格把控各道工序的施工质量和进度,确保主塔按期封顶。总结的经验可为类似工程提供借鉴。 相似文献
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马岭河斜拉桥塔梁同步施工可行性研究 总被引:1,自引:0,他引:1
马岭河特大桥8号墩采用塔梁同步施工,9号墩采用先主塔后主梁的非塔梁同步施工,故分别建立了这两种施工方法的模拟计算模型。通过对这两种模型的计算结果进行对比分析,从主梁和主塔两个方面论证了塔梁同步施工的可行性。结合该桥的工程实例,分别阐述了在塔梁同步施工情况下主梁和主塔施工所采取的控制措施。为以后其他采用塔梁同步施工的斜拉桥建设提供参考。 相似文献
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在沪苏通长江公铁大桥主航道桥中,以大桥29号墩斜拉索挂设施工为例,逐个识别施工特点,并进行前置条件分析,而后制定相应对策.塔端挂设滞后主塔3个节段解决塔柱结构安全问题,大型塔式起重机解决塔端挂设动力问题,斜拉索吊机中支点处锚固张拉解决主梁结构安全问题,架梁起重机后锚梁结构、支撑结构设计考虑避让斜拉索和梁面锚拉板解决施工... 相似文献
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南浦大桥主桥的两座钢筋混凝土塔柱高154m,其中主桥塔下横梁是塔柱的关键部位,位于塔柱标高+38.0~+46.0m处,为7000(宽)×8000(高)×40000~42800mm(长)的梯型空腹后张高强钢丝束预应力箱型梁(见图1)。据有关资料,象南浦大桥这样的高耸塔、巨型梁的预应力后张施工在国外都少见,所以我们在施工中碰到不少困难,但在中国建筑科学研究院结构所的关心和大连拉伸机厂的积极配合之下,特别是经过现场工人和技术人员的艰苦努力,采用XM型锚具,顺利完成了下横梁的预应力张拉。我们通过这次工程实践获得了一些经验、教训和认识,特在此提供给大家,以便为大桥下 相似文献
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斜拉桥倾斜的主塔塔柱在施工过程中会产生相应方向的位移,对塔柱根部、塔柱与横梁交界处的应力有较大影响。某宽幅斜拉桥塔柱为钢筋混凝土结构,为避免混凝土拉应力超标,在塔柱施工过程中一般要设置主动横撑,并施加初始顶推力。依托该宽幅斜拉桥H型主塔,通过主塔施工过程仿真计算,研究横撑位置、施工工序等对塔柱的影响,比选并提出最优方案。 相似文献
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A. K. Ghorbani‐Tanha A. Noorzad M. Rahimian 《The Structural Design of Tall and Special Buildings》2009,18(4):371-385
With a height of 435 m, Milad Tower, situated in north‐west of Tehran, Iran, would be the fourth highest telecommunication tower of the world. This tower has the largest head structure among its counterparts. Preliminary studies demonstrate that the upper part of the tower has excessive wind‐induced acceleration‐related vibrations beyond human comfort limit during wind events. In this paper, the effectiveness of tuned mass damper (TMD) on the suppression of wind‐induced motion of Milad Tower is examined through mathematical analyses. The tower is modelled as a vertical linear cantilever beam, with 57 degrees of freedom. The fluctuating wind speed is assumed to be a stochastic process which is identified by an appropriate power spectral density function. Random vibration analyses were carried out to determine response statistics. The possible application of TMDs in suppressing wind‐induced motions of the tower was investigated, and a TMD was designed to be installed at the sky dome. The results clearly show that the designed TMD has a considerable influence on the suppression of the structural response of the tower below human comfort limits. The authors believe that Milad Tower can be considered as a benchmark control problem for television and telecommunication towers by the structural control community. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
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为确保斜风作用下大跨度悬索桥的抗风稳定性,采用考虑静风效应和全模态耦合影响的斜风下大跨度桥梁三维精细化颤振分析程序,以润扬长江大桥南汊悬索桥为工程背景,在0°和±3°初始风攻角下,分析了斜风下成桥状态和加劲梁从跨中向两侧桥塔对称架设全过程的颤振稳定性,并揭示了斜风作用和静风效应对成桥和施工状态大跨度悬索桥颤振稳定性的影响。结果表明:悬索桥成桥和施工状态的颤振临界风速随着风偏角的增加呈现波动起伏变化特征,且主要在斜风情况下达到最低值;斜风作用和静风效应不会影响悬索桥施工期颤振稳定性的演变规律,但会显著降低悬索桥成桥和施工状态的颤振稳定性;斜风作用使得成桥和施工状态颤振临界风速的最大降幅平均值分别达到了8.0%和19.6%,而斜风和静风的综合效应则进一步劣化悬索桥成桥和施工状态的颤振稳定性,最大降幅平均值分别达到了11.5%和22.4%,因此大跨度悬索桥成桥尤其是施工状态的颤振稳定性分析必须考虑静风和斜风综合效应的不利影响。 相似文献
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针对复杂异形桥梁结构风荷载参数的不确定性问题,采用计算流体动力学方法,对主梁和桥塔的风荷载参数进行数值风洞模拟。研究了不同气流攻角对主梁结构风荷载的影响及不同气流风偏角对桥塔风荷载的影响。通过数值计算,为相似复杂异形桥梁风荷载参数取值提供了参考。 相似文献
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运用Midas和SAP2000软件,分析计算扣锚索、工作索、缆风索和塔架的结构强度和稳定性.结合施工经验对武隆乌江特大桥钢筋混凝土预制箱形拱桥缆索吊装进行了双肋合龙改单肋合龙的优化设计,并阐述了施工中的关键技术和质量控制措施,总结大跨度缆索吊装设计和施工工艺.成功地保证施工安全,创造出良好的经济效益和社会效益. 相似文献
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Zhi Sun Nin Hou Haifan Xiang 《Frontiers of Architecture and Civil Engineering in China》2009,3(1):18-24
Tower cranes are commonly used facilities for the construction of high-rise structures. To ensure their workability, it is
very important to analyze their response and evaluate their condition under extreme conditions. This paper proposes a general
scheme for safety and serviceability assessment of high-rise tower crane to turbulent winds based on time domain buffeting
response analysis. Spatially correlated wind velocity field at the location of the tower crane was first simulated using an
algorithm for generating the time domain samples of a stationary, multivariate stochastic process according to some prescribed
spectral density matrix. The buffeting forces applied to the structure were computed according to the above-simulated wind
velocity fluctuations and the lift, drag, and moment coefficients obtained from a CFD computation. Those spatially correlated
loads were then fed into a well calibrated finite element model and the nonlinear time history analysis was conducted to compute
structural buffeting response. Compared with structural onsite response measurement, the computed response using the proposed
method has good precision. The proposed method is then adopted for analyzing the buffeting response of an in-use tower crane
under the design wind speed and the maximum operational wind speed for safety and serviceability assessment. 相似文献
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斜拉桥作为一种常见的大跨度桥梁结构形式,在施工中一般应对其斜拉索以及塔梁进行检测,并对相应的施工过程进行控制,以保证施工的顺利进行,确保施工质量。文中以某斜拉桥的施工为背景,较为详细地讨论了斜拉桥钢筋混凝土桥塔、主梁检测断面的布置、检测工作的内容以及施工质量检测标准,以期为同类工程的检测提供参考。 相似文献
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为完成红岛航道桥塔柱防腐涂装及避雷塔等辅助设备的安装,施工单位设置了主塔施工工作平台,安装了升降吊篮,考虑桥上风力、风向对涂装的不利影响,对吊篮安全性能进行了验算,并对其安装及拆除方案进行了阐述,以确保施工安全。 相似文献