大跨度空间钢结构施工技术研究与监测

发布时间：2018-03-17 20:03

本文选题：大跨度空间结构　切入点：钢结构　出处：《天津大学》2014年博士论文　论文类型：学位论文

【摘要】：随着我国综合国力的提高和经济的发展,建筑形式呈现出多样化的发展趋势。现代钢结构正朝着高、大、复的方向发展,复杂钢结构的大跨、高层建筑愈来愈多,它们在施工过程中的力学问题也越来越受到广泛的关注。针对弦支穹顶叠合拱结构,就预应力张拉过程中空间钢拱是否与下部网壳结构协同受力,制定了两种施工方案。对此两种施工方案,分别进行了弦支穹项叠合拱结构施工全过程分析,对预应力张拉施工过程中索力、杆件内力和结构变形进行了全过程分析。为满足预应力施工过程的需要、保证工程顺利进行,对结构进行施工监测,从监测结果来看,实测结果很好地验证了理论计算结果,同时说明了通过有限元计算软件进行施工仿真计算的可行性。对大跨度大悬挑吊挂结构施工过程中的关键技术问题进行研究,并进行了施工过程力学模拟分析。针对本工程的结构特点,确定了临时支撑的设置原则和卸载方案,采用等效杆端位移法进行临时支撑的卸载数值模拟。对大悬挑结构卸载进行了数值模拟及施工监测。针对钢框架-支撑与空间交叉桁架复合结构施工中的重点难点,对结构施工变形控制措施及结构整体卸载进行了施工过程有限元分析模拟,考察荷载转换过程中结构的强度与刚度变化,为施工方案的确定提供理论支持,保证施工过程的顺利进行。采用电阻应变片静态有线应力监测、电阻应变片静态无线应力监测和钢弦式应变传感器应力监测三种监测手段,对天津图书馆钢框架-支撑与空间交叉桁架复合结构关键节点的应力状态进行施工全过程监测。三种手段监测结果相互对照,可以及时发现问题,保证了监测结果的准确性和有效性,以及现场施工的顺利进行。将向心关节轴承引入弦支穹顶结构的撑杆上节点,形成了向心关节撑杆上节点,配合不可滑动撑杆下节点以及撑杆形成了向心关节索杆体系。选取工程实际向心关节轴承撑杆上节点进行了足尺试验,并进行了有限元模拟。提出了基于非线性有限元技术的反分析方法,分析了向心关节索杆体系弦支穹顶结构的施工张拉过程,确定了其施工放样状态。对向心关节索杆体系弦支穹顶结构张拉过程进行施工监测,通过监测各张拉阶段上部结构位移、支座位移,确保张拉过程中结构安全可靠,同时验证了施工张拉数值模拟方法的可行性。对切割加长大跨度结构滑移施工技术的总体思路和实际关键控制点进行了研究,通过对腹杆加强、支撑架搭设、滑移顶推点设计、滑移过程中的同步控制等技术措施进行研究,保证了工程的顺利实施。为了评定其滑移过程中桁架结构的安全性,使结构在滑移过程中保持同步且不因应力过大产生过大的变形,实现桁架整体滑移施工,并且满足其后续施工和使用的要求,对该桁架结构整体滑移过程中的部分关键杆件应力应变进行了现场监测。针对以上几种不同形式的大跨度空间钢结构,根据其结构受力特点、结构布置形式和现场工作条件等因素,确定相应的测点布设方式,力争达到“监测完整、性能稳定兼顾性价比最优”的布设原则,为今后相关结构工程的施工监测方案确定提供参考和理论依据。
[Abstract]:With the rapid development of China's comprehensive national strength and economic construction form, showing a diversified trend. Modern steel structure is a high, large, complex direction, complex steel structure of large span, more and more high-rise buildings, they are in the process of construction of the mechanical problems are more and more attention. Aiming at suspend dome with stacked arch structure, spatial prestressing process of steel arch and the lower shell structure is synergy force, made two kinds of construction schemes. This two kinds of construction schemes, were a suspen dome with stacked arch structure to analyze the whole process of construction, the cable force in the construction process of prestressed tension bar deformation, internal force and structure are discussed. In order to meet the needs of the prestressed construction process, ensure the smooth progress of the project, the construction monitoring of the structure, from the monitoring results, the measured results are in good agreement with the theory. The results, and explain the feasibility of construction simulation calculation by FEM software. The large-span suspended key technical problems in the construction process of the pick hanging structure is studied, and the simulation analysis of construction process mechanics. According to the structure characteristics of this project, the establishment principle and the unloading plan determined the temporary support. Numerical simulation of unloading the equivalent rod end displacement method for temporary support. The large cantilever structure of unloading numerical simulation and construction monitoring. On the construction of steel braced frame and space truss composite structure to cross point, construction of a finite element analysis simulation of deformation control measures and the whole body of the structure construction study of load conversion process, the structural strength and stiffness changes, provide theoretical support for the determination of construction scheme, to ensure the smooth progress of the construction process. Using electric resistance Static strain gauge cable stress monitoring, resistance strain gauge static wireless stress monitoring steel wire strain sensor and stress monitoring of the three monitoring methods, the whole process of construction monitoring of Tianjin Library of steel braced frame and space truss composite structure cross key nodes stress state. The three means of monitoring results of mutual control. You can find the problem in time, to ensure the accuracy of monitoring results and effectiveness, and smooth progress of the construction site. The introduction of sphericalplain bearing supporting nodes of suspendome structure, form a centripetal joint strut node, with sliding strut joint and struts formed a centripetal joint cable strut system is selected from the project. The actual sphericalplain bearing supporting nodes are test and finite element simulation. The back analysis method of nonlinear finite element technique based on the analysis of the heart Cable strut joint suspendome construction process of tension structure, the construction lofting state is determined. The sphericalplain cable strut system suspendome tensioning construction process monitoring, through the monitoring of the tension displacement of superstructure phase displacement, ensure the tensioning process is safe and reliable, and verification the tension of the numerical simulation method. The feasibility of the general idea of cutting construction technology span structure and the actual slip up the critical control points were studied, through the strengthening of the brace, support frame erection, sliding pushing point design, research technical measures in the process of synchronous sliding control, to ensure the smooth the implementation of the project. In order to assess the safety of the truss structure during sliding, the structure to keep pace and not due to excessive stress resulting from the deformation in the sliding process, the realization of the overall truss sliding construction, and Meet the following construction and use requirements, the whole sliding the truss structure parts in the process of the key elements of stress and strain of field monitoring. The large span steel structure for the above several different forms, according to the stress characteristics of the structure, structure and working conditions and other factors, determine the layout of measuring point accordingly, and strive to achieve a complete monitoring, the layout principle of stable performance, taking into account the cost optimal to provide reference and theoretical basis for future structural engineering construction monitoring scheme is determined.

【学位授予单位】：天津大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TU758.11

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