筒芯内模现浇混凝土空心楼盖内力分析及设计方法研究

【作者】 李海涛；

【导师】 刘立新；

【作者基本信息】 郑州大学 ， 结构工程， 2007， 硕士

【摘要】 现浇混凝土空心楼盖具有结构高度小、自重轻、刚度大、施工便捷、隔声隔热保温等优势，在多高层大跨房屋建筑中应用前景广阔。目前应用中最大薄弱环节是现浇空心楼盖的内力分析，楼盖空心部分及实腹(暗梁)的不同布置方式，使其内力分布相差很大。由于试验研究的局限性，虽可以从宏观上看到板的变形特征，但难以从微观角度了解空心板内部应力应变分布状况。板的细部构造设计缺少研究依据，空心楼盖的设计理论尚不完善。采用细密划分的有限单元体，把空心楼盖作为一个空间体模型，进行仿真分析，可以最接近实际地反映出现浇空心楼盖的受力变形特征。本文采用通用有限元软件ANSYS对空心楼盖整体受力性能进行仿真分析，并把结果和PKPM设计软件的分析结果进行了比较。本文首先对理想支承单区格实心楼盖和典型布筒空心楼盖，采用相同的单元类型和网格划分方案进行三维实体有限元分析；将计算结果与其经典解对比，验证了该划分方法的准确性，为后续确定有限元分析的单元类型和网格划分方案提供了依据。通过对比对边简支现浇混凝土空心楼盖的两种情形应力、挠度，证明了空心楼盖在孔向、径向两个方向的截面应力和抗弯刚度存在差异，径向截面的抗弯刚度可取孔向截面抗弯刚度的0.97倍。根据上述有限元分析方案，分别对柱支承现浇混凝土空心楼盖和实心楼盖进行有限元计算，考察空心对内力及变形的影响以及空心楼盖的基本性状，证明了其受力和挠度分布与实心楼盖整体上相似，但细节上有一定差别。将ANSYS有限元软件计算的结果和对比实心楼盖在PKPM(SATWE)中计算的结果对比分析，提出按照现有设计软件PKPM(SATWE)的计算结果进行修正的建议，并给出了相应的调整系数，供设计人员参考。提出了筒芯内模空心楼盖各区格柱上板带、跨中板带总弯矩占区格总弯矩的比率系数，柱上板带、跨中板带支座负弯矩、跨中正弯矩占跨中板带总弯矩的比率系数；给出筒芯内模空心楼盖计算经验系数的建议，列出了各区格分配系数表。更多还原

【Abstract】 The cast-in-situ hollow concrete floor system will be more widely used inmultiple-story and high-rise buildings for its advantages: low structural height andsmall deadweight and relatively high stiffness and convenient construction and thepredominance of noise isolation, heat insulation, thermal retardation. The mostvulnerable spot during application now is the inner mechanics analysis of thecast-in-situ hollow concrete floor system. Because of the different arrangement waysof hollow and dark beam, the phase contrast of the inner mechanics distribution isvery large. It is difficult to know the state of stress and strain distribution in the innerhollow floor from microscopic view because of the limitation of experiment research,although we can see the deformation trait from macroscopic view. The detailconstitution design of the hollow floor lacks research results to refer to, and the designtheory of hollow floor is not perfect. We analyze the hollow floor system as a spatialmodel by using finite element divided finely. From that the stress and deformation ofthe hollow floor can be reflected more actually. This paper will analyze the stressperformance of the whole hollow floor system by using the ANSYS element software,and compare the results of it with the analysis results of the PKPM design software.The thesis proposed the comparative analysis on solid and hollow slabs under theideal constraint condition by adopting the same solid isoparametric elements andmeshing methods. By comparing the compute results with classical result, it wasproved that the divide methods was accurate. That supplied the reference fordetermining the element type and meshing ways for the later finite analysis. Bycomparing the stress and deflection of the hollow floor supported by opposite sideduring the two conditions, it is proved that the stress and stiffness of the hollow floorsectional areas are different in the transverse and longitudinal directions. Thetransverse section stiffness is about 0.97 times of stiffness of the longitudinal section.According to the finite analysis methods mentioned above, cast-in-situ hollowand solid floor supported by column were computed respectively. The influence tostress and deformation brought by the holes and basic properties were analyzed. The stress and deflection distribution of the hollow floor is similar to that of the solid floor,but they are different in details. After comparing the results of ANSYS software withthe results of PKPM (SATWE) software, the amendment advice about the results ofPKPM (SATWE) software was put forward., and auxiliary value was supplied fordesigner to refer to. The ratio coefficient of the moment of flexure of the column stripand middle strip to that of all was put forward. Also, the ratio coefficient of thesupport negative moment of flexure and the midspan positive moment of flexure ofthe column strip and middle strip to that of all respectively ware put forward. Thesuggestion about the direct design method of the tube hollow floor was supplied. Thetables of distribution coefficient were listed.更多还原