支模钢平台在高空多层混凝土连廊施工中的应用研究

发布时间：2019-03-28 11:33

【摘要】：高空连廊结构是近二十年来逐渐发展起来的一种新型结构型式,由于其外观上的独特性及功能上的多样性,越来越多的设计师青睐于这种悬空结构。本文以扬州智慧大厦高空多层混凝土连廊的施工为研究背景,在对比分析了几种施工支模方法的基础上,结合本工程的具体特点,确定了将空间钢桁架承力结构作为连廊施工的支模平台,并针对下列几个施工难点问题展开了研究：(1)支模钢平台及钢牛腿的设计选型问题。通过分析对比两种支承方式的空间钢桁架结构—上承式和斜撑式,确定了以上承式空间钢桁架结构作为支模钢平台的结构型式,并分析了该结构的自振特性。考虑到钢平台使用阶段的支座反力较大,所以支承牛腿的设计采用了抗剪能力较强的双腹板箱型牛腿。此外,还研究了钢平台在使用阶段对已建主体结构的影响,并对拉应力较大位置采取了加强措施。(2)支模钢平台的拆除期问题。本文按照一定的分析思路,先对第1道连廊梁板单独承受第2道施工时的脚手架布置进行设计,确定出基本荷载信息,然后利用ANSYS分析了半刚性连接的钢管脚手架整体结构在不同荷载工况下的受力行为,通过将脚手架的支反力导入到第1道连廊梁板与主体结构的整体模型中,验算了第1道连廊梁板在10d龄期下单独承受第2道施工时的受力性能,结果显示,各杆件的变形均满足要求,但是次梁的承载力不满足要求,需对次梁采取加强措施。加强次梁后,理论上施工完第1道连廊梁板即可拆除钢平台,但实际施工过程中,为了保证工程质量和安全,待浇完第2道梁板混凝土后再拆除钢平台。(3)支模钢平台的安装问题。作为本工程高空混凝土连廊施工的支模钢平台为空间钢桁架结构,其常见的安装方案有多种,根据施工现场的实际情况,初选了支模钢平台的两种安装方案,通过对两种方案进行多指标综合比较,最终确定了采用优势最为明显的整体提升法来安装和拆除支模钢平台。此外,文章分析并解决了本工程提升过程的一些技术难点问题,同时给出了整体提升安装的具体思路。(4)支模钢平台施工过程中的控制问题。首先,基于对计算结果的评价指标,从3种吊点布置方案中确定了最为合理的8吊点方案。在已知吊点布置的位置及数量后,分两种情况研究了提升位移差限值的控制问题,经过比较,确定了将各吊点的位移差限值设为±30mm。随后,针对钢平台在提升阶段的稳定性问题利用ANSYS进行了分析计算,结果表明钢平台在实际提升过程中不会发生平面外失稳。实际施工时,钢平台在浇完第2道连廊梁板后进行拆除,所以采用生死单元法研究了施工第2道梁板时钢平台的受力性能,得出结论：以承受第1道连廊梁板的施工来设计钢平台是可行的,且钢平台在施工完第2道梁板后再进行拆除也是可行的。最后,文章还论述了钢平台整体提升过程的控制与监测措施。本文的研究,希望能为类似高空多层混凝土连廊的施工提供借鉴和参考。
[Abstract]:The structure of the high-altitude corridor is a new type of structure that has gradually developed in the past two decades. Due to its unique and functional diversity, more and more designers favor the suspended structure. In this paper, based on the construction of the high-altitude multi-layer concrete corridor in the intelligent building of Yangzhou, this paper, on the basis of the comparison and analysis of several methods of construction formwork, has determined the bearing structure of the space steel frame as the formwork platform for the continuous corridor construction. The problems of the design and selection of the steel platform and the steel leg are studied in this paper. In this paper, the structural type of the above-bearing space steel frame structure is determined as the structure of the formwork steel platform, and the natural vibration characteristics of the structure are also analyzed by analyzing the upper and lower bearing types and the diagonal braces of the space steel frame structure of the two support modes. Considering that the bearing counterforce of the use stage of the steel platform is large, the design of the support leg is a double-web box-type bull leg with strong shear capacity. In addition, the influence of the steel platform on the structure of the built-in main body in the use stage is also studied, and the measures for strengthening the tensile stress are also taken. (2) The removal period of the formwork steel platform. In this paper, according to a certain analysis method, the design of the scaffold layout in the first lane of the first corridor is designed and the basic load information is determined, and then the stress behavior of the whole structure of the semi-rigid-connected steel pipe scaffold under different load conditions is analyzed by using the ANSYS. By introducing the supporting reaction force of the scaffold into the whole model of the first corridor beam plate and the main body structure, the stress performance of the first corridor beam slab under the 10-d age is checked, and the results show that the deformation of each rod meets the requirements, However, if the bearing capacity of the secondary beam does not meet the requirements, the secondary beam shall be strengthened. After the secondary beam is strengthened, the steel platform can be removed by the construction of the first corridor beam and slab in theory, but in the actual construction process, in order to ensure the project quality and safety, the steel platform shall be removed after the second beam and slab concrete is to be poured. (3) The installation of the formwork steel platform. As the formwork steel platform for the construction of the high-altitude concrete continuous corridor of the project is a space steel frame structure, the common mounting scheme of the steel frame is various, and according to the actual situation of the construction site, the two installation schemes of the support die steel platform are selected, and the multi-index comprehensive comparison is carried out on the two schemes, The integral lifting method with the most obvious advantages is finally determined to install and remove the formwork steel platform. In addition, the paper analyzes and solves some technical difficulties in the lifting process of the project, and gives the concrete idea of overall lifting and installation. (4) Control problems during the construction of the formwork steel platform. First, based on the evaluation index of the calculation results, the most reasonable 8-point scheme is determined from the three-point arrangement scheme. After the position and the number of the known lifting points are known, the control problem of the limit of the lifting displacement difference is studied in two cases, and the limit of the displacement difference between the lifting points is determined to be equal to 30 mm after comparison. Then, the stability problem of the steel platform in the lifting stage is analyzed and calculated by using the ANSYS, and the result shows that the steel platform will not lose out-of-plane instability in the actual lifting process. In the actual construction, the steel platform is removed after the second corridor beam slab is poured, so the force performance of the steel platform is studied by the life-and-death unit method, and it is concluded that the steel platform is feasible to design the steel platform with the construction of the first corridor beam slab. And the steel platform is also feasible after the construction of the second beam slab. Finally, the paper also discusses the control and monitoring measures of the whole lifting process of the steel platform. The research of this paper is to provide reference and reference for the construction of similar high-altitude multi-layer concrete corridor.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU755;TU974

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