【作者】 张君；

【导师】 毕贵权； 王秀丽；

【作者基本信息】 兰州理工大学 ， 结构工程， 2019， 硕士

【摘要】 大跨度空间结构造型优美,受力合理,在近些年的建筑物设计中越来越受到设计师的青睐。大跨度空间结构形式多样,各具特点,其中网壳结构由于构造简单,受力均衡,在受弯、受压、受扭状态下均能保持良好的结构性能,所以在体育馆、游泳馆等大型公共建筑中得了到广泛应用。在考虑大跨度空间结构优点的同时,其在建造过程中的复杂程度和施工难度更要引起重视。由于此类结构建筑的施工周期较长,结构形式相对复杂,在建造过程中结构构件的力学变化情况难以判断,所以各种垮塌和失稳事故在大跨结构的施工中也是屡见不鲜,因此大跨结构在施工过程中力学响应的研究对预防各种工程事故的发生有着重大意义。本文依托于天水体育中心游泳馆实际工程项目,对大跨度空间钢网壳结构的施工过程进行了施工力学性能研究,并结合相关的结构安全评估理论对游泳馆整体结构进行了安全性评估,详细的研究工作内容如下:1.以天水体育中心游泳馆为例,分析了钢网壳结构在拼装过程中的力学形态变化情况。首先利用有限元软件ANSYS的瞬态分析功能对结构的吊装过程进行了动力分析,针对模型构建时单元的选择,边界的定义以及参数设置做了详细的阐述,对比了不同的起吊速度对结构杆件应力产生的放大效应;然后利用MIDAS GEN对钢网壳结构顶升及整体拼装过程进行了模拟,从模拟结果可以看出结构在施工过程中杆件受力处于安全状态;在整体结构的卸载阶段运用支座位移法进行模拟分析,从模拟结果可以看出,随着卸载的逐步进行,整体钢网壳结构内部不断发生内力重分布,应力值呈增大趋势,最终趋于稳定。2.采用监测设备对实际工程的施工过程进行实时力学监测,并将所监测的数据与数值模拟计算的数值进行对比分析。从整体的数据对比来看,二者结果总体趋势基本吻合,验证了有限元模拟分析的准确性,同时也对个别测点数据的差异性进行了原因分析,为以后的类似工程提供参考依据。3.运用层次分析法和模糊数学理论,并结合实际工程的相关资料对游泳馆结构进行安全性评估,通过量化的分析方法对结构进行详细的分析判断,为结构的安全性提供保障。综上所述,进行大跨度空间结构施工力学分析对建筑物的施工安全有着重要的预警作用,运用科学系统的方法进行结构安全性评估对后期建筑结构的健康运营有着重要意义。本文所采取的分析方法以及实测数据对今后类似大跨度空间结构的研究有着指导性意义。更多还原

【Abstract】 The large-span spatial structure is beautifully shaped and reasonable in force.In the design of buildings in recent years,the large-span spatial structure has become more and more popular among designers.The large-span spatial structure has various forms and different characteristics.Reticulated shells are widely used in gymnasiums,swimming pools and other large public buildings because of their simple structure,balanced stress and good structural performance under bending,compression and torsion.While considering the advantages of the large-span space structure,the complexity and difficulty of construction should be paid more attention.Due to the long construction period of this type of structural building and the relatively complicated structural form,it is difficult to judge the mechanical changes of structural construction during the construction process,so various collapse and instability accidents are also common in the construction of large-span structures.Therefore,the study of the mechanical response during the construction of large-span structures is meaningful for preventing the occurrence of various engineering accidents.Based on the actual project of the swimming pool of Tianshui Sports Center,this paper conducted a mechanical analysis of the construction process of the large-span space steel mesh shell structure,and combined the relevant structural safety assessment theory to conduct a safety assessment of the structure of the swimming pool.The detailed research work is as follows:1.Taking the swimming pool of Tianshui Sports Center as an example,this paper analyzed the mechanical morphology changes of steel mesh shell structure during the assembly process.Firstly,the dynamic analysis of the lifting process of the structure was carried out by using the transient analysis function of the finite element software ANSYS.The selection of the unit,the definition of the boundary and the parameter setting were elaborated in the construction of the model.This paper compared the amplification effect of structural bar stress at different lifting speeds.Then MIDAS GEN was used to simulate the middle lifting process of the steel reticulated shell structure.From the simulation results,it could be seen that the jacking structure was in a safe state during the jacking process;In the unloading stage of the whole structure,the life-and-death element method was used for simulation analysis.It could be seen from the simulation results that with the gradual unloading,the internal force redistribution continuously occured in the overall steel reticulated shell structure,and the stress value increased,eventually tending to stable.2.The monitoring instrument was used to carry out structural real-time mechanical monitoring of the actual engineering construction,and the actual data monitored was compared with the numerical values of the simulation calculations.The overall data comparison showed that the results were in good agreement,verifying the accuracy of the finite element simulation analysis,and also analyzing the cause of the difference in the data of individual measurement points,providing a reference for similar projects in the future.3.This paper used the analytic hierarchy process and fuzzy mathematics theory,and combined the relevant data of actual engineering to evaluate the safety of the swimming pool structure..The quantitative analysis method was used to analyze and judge the structure in detail,which provided guarantee for the safety performance of the structure.In summary,the analysis of construction mechanics of long-span spatial structures plays an important role in early warning of construction safety of buildings.It is of great significance for the healthy operation of later construction structures to use scientific and systematic methods to carry out structural safety assessment.The analysis methods and measured data adopted in this paper have guiding significance for the study of long-span spatial structure in the future.更多还原