400m跨双层网壳结构设计与施工技术研究

发布时间：2018-04-14 23:32

  本文选题：大跨度 + Midas　； 参考：《太原理工大学》2014年硕士论文

【摘要】：2008年奥运会以后,我国大跨度空间钢结构得到了空前的发展,各种结构形式、跨度及规模的建筑物不断出现。钢结构优越的材料性能、超快的施工速度及可持续重复利用等优点,均表明人类已具备建设300-1000m超大跨度,及更大空间钢结构的能力。目前国内外的建筑物跨度多在300m以内,2000年建成的千年穹顶以钢索和膜材做成的索膜结构直径为320m。休斯敦受飓风和热浪袭击严重,提出了ETFE气枕作为维护结构,跨度1600m,高450m的城市穹顶。2010年,俄罗斯某公司提出预在西伯利亚废弃的矿坑建一个直径1200m,可容纳10000人的三层建筑。随着全球变暖,环境恶化,资源的短缺,及应对未来更为艰难的生存环境,人类对建设超大跨度,超高层的公共建筑越来越向往,这些建筑不仅能满足一些重大的社会经济活动的要求,内部具有自给自主的系统,提供给人们舒适的工作环境、维持正常的生活,还可以在地震等自然灾害来临时,为灾民提供一个安全的避难场所。本文选用双层球面网壳结构体型,其跨度400m,矢高70m,进行结构设计及施工技术研究。基于太原地区的场地特征条件,以某体育馆的整体结构模型为研究对象做如下工作：1)安装方法。本文对大跨度空间钢结构的安装方法进行了总结与分析,针对超大跨度结构自重大,杆件复杂的特点,对几种常用的安装方法进行了可行性分析。其中攀达,整体提升、整体顶升、折叠展开式等方法较适用,但仍需对关键技术难点进行设计。2)模型设计。在3D3S中建立跨度为400m的凯威特K-6型双层球面网壳模型,导入Midas/Gen软件,将杆件进行分类分组,进行钢结构设计及截面优化,减少用钢量,最终网壳屋盖总用钢量为27058t,即每平方米用钢量为191.92kg。3)静力分析。通过Midas/Gen软件对各荷载组合控制下的结构进行应力、位移、反力、内力的计算,分析结构静力特性,应力比最大为0.85,最大位移为349.04mm,均符合规范要求。4)施工阶段。根据工程实况及现场施工的需要,采用整体提升法,施工阶段最大位移为38.92mm,应力为-194.16N/mm2,最大反力为6442.77kN,所需提升荷载最大为1019.01吨。5)变形预调。采用正装迭代法进行变形预调时,合拢后Z向位移最大已经达到-41.40mm,经过二次迭代后,最大位移控制在0.014mm。施工后与原设计位置相接近。6)分布卸载。对80个临时支承支架分11步卸载,最大位移为41.39mm。7)合拢温差。对温差为-40℃～40℃进行了研究,得出-20℃对结构的影响最大,20℃最小,合拢温差应控制在10℃～20℃间。8)采用提升胎架及拉索的组合,并通过预应力拉索,协调整体提升时水平推力的影响。
[Abstract]:After the 2008 Olympic Games, the long-span spatial steel structures in China have been developed unprecedentedly, and various structural forms, span and scale buildings have been emerging.The excellent material properties of steel structures, super fast construction speed and sustainable reuse indicate that human beings already have the ability to build 300-1000m super-span and larger space steel structures.At present, the span of buildings at home and abroad is less than 300m. The diameter of cable-membrane structure made of steel cable and membrane materials built in 2000 is 320m.Houston was hit hard by hurricanes and heat waves and proposed a ETFE cushion as a maintenance structure with a span of 1600m and a 450m high urban dome. In 2010, a Russian company proposed a three-story building with a diameter of 1200m in an abandoned mine in Siberia that could accommodate 10000 people.With global warming, environmental degradation, a shortage of resources, and a more difficult living environment for the future, people are increasingly looking forward to building super-span, super-tall public buildings.These buildings can not only meet the requirements of some major social and economic activities, but also provide people with a comfortable working environment and a normal life. They can also be used in times of natural disasters such as earthquakes.Provide a safe haven for the victims.In this paper, the double layer spherical reticulated shell with a span of 400 m and a sagittal height of 70 m is selected to study the structural design and construction technology.Based on the site characteristics of Taiyuan area, the overall structure model of a gymnasium is studied as follows: 1) installation method.In this paper, the installation methods of large span spatial steel structures are summarized and analyzed.The methods of climbing, whole lifting, whole lifting and folding expansion are more suitable, but the key technical difficulties still need to be designed. 2) Model design.The model of K-6 double-layer spherical reticulated shell with a span of 400m is established in 3D3S, and the software Midas/Gen is introduced into the model, the members are classified and grouped, the steel structure design and section optimization are carried out, and the amount of steel used is reduced.Finally, the total steel used for reticulated shell roof is 27058 t, that is, 191.92 kg 路3 kg 路3 per square meter.The stress, displacement, reaction force and internal force are calculated by Midas/Gen software. The static characteristics of the structure are analyzed. The maximum stress ratio is 0.85 and the maximum displacement is 349.04mm.According to the actual situation of the project and the need of the field construction, the integral lifting method is adopted. The maximum displacement of the construction stage is 38.92 mm, the stress is -194.16 N / mm ~ 2, the maximum reaction force is 6442.77 kN, and the maximum lifting load is 1019.01 tons 路5) deformation presetting.The maximum Z-direction displacement has reached -41.40 mm after closing, and the maximum displacement is controlled at 0.014 m after the second iteration.After construction and the original design close to. 6) distribution of unloading.The 80 temporary support supports are unloaded in 11 steps with a maximum displacement of 41.39 mm. 7) closure temperature difference.The temperature difference of -40 鈩，

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