三维空间相干相关激励下大跨空间网格结构地震响应研究

Seismic ground motions at a structural site are spatially correlated and coherent. It is more realistic to consider that the ground motions at multiple supports of a structure are spatially correlated and coherent than to assume that they are spatially uniform. The large-span space latticed structures has often used because of its light weight and relative ease to construct. The span of space latticed structures has increaseds gradually in recent years. The influence of the coherency on the seismic responses of structure has been investigated but the effect of the spatial correlation and coherency on the responses for the large-span space latticed structures has not been systematically investigated. As a matter of fast, on the basis of previous studies, the effects of spatial seismic excitations on large-span space latticed structures are investigated in detail. The main content of this study includes: (1) study characteristics of actual seismic ground motion, simulation of three-dimensional spatially correlated and coherent multiple-support excitations. (2) the seismic response of large-span space latticed structures under uniform and spatially correlated and coherent three-directional excitations will be investigated through the theoretical and numerical study, influence of spatially correlated and coherent on seismic response of large-span space latticed structures is studied. (3)The reasonable and effective seismic design method of large-span space latticed structures to consider the spatial variation effects by multi-support excitations will be developed. Through these studies, the useful seismic design method will be established to solve the actual engineering design problems, which will provide the reliable theoretical foundation and technical support for the engineering applications of the large-span space latticed structures.

地震动传播至结构场地时具有空间相关性和相干性，考虑地震动空间相关性和相干性的多点输入比一致输入更符合实际。空间网格结构因其重量轻易于建造等优点获得了广泛应用，并且跨度不断增加。空间相干性对结构地震反应的影响已有研究，但空间相关性和相干性对大跨空间网格结构地震反应的影响还没有系统研究过。为此，申请者拟对大跨空间网格结构的地震动空间效应展开深入系统的研究，主要内容包括：（1）研究实际地震动场特性，模拟三维空间相干相关地震动记录；（2）通过数值模拟和理论分析等手段对大跨空间网格结构地震动空间效应展开研究，探索地震动空间相干性和相关性对结构的影响程度和机理；（3）提出合理高效的三维空间相干相关激励下大跨空间网格结构的抗震设计方法。通过本项目的研究建立起可应用于工程实践的大跨空间网格结构抗震理论，为大跨空间网格结构的发展提供理论基础和技术保障。

地震动传播至结构场地时具有空间相关性和相干性，考虑地震动空间相关性和相干性的多点输入比一致输入更符合实际。空间网格结构因其重量轻易于建造等优点获得了广泛应用，并且跨度不断增加。故而，研究大跨空间网格结构地震动空间效应非常重要。. 本项目以空间网格结构为研究对象，对大跨空间网格结构地震动空间效应展开研究，探索地震动空间相干性和相关性对结构的影响程度和机理。主要开展了以下四个方面的研究工作：（1）重点研究了地震动场特性和地震动场模拟方法，分别采用扩展随机点源法和基于谱表示的三角级数合成法来模拟地震动记录，并将模拟记录应用于空间网格结构，调查多点输入下结构反应与一致输入的差异，获得了地震动空间变化性对结构的影响规律和机理；（2）研究了结构初始几何缺陷的建模方法，采用联立自回归模型对球面及柱面网壳结构的初始几何缺陷进行建模，得到了空间相关的初始几何缺陷对满足结构稳定性的结构承载能力概率分布和网壳结构的可靠度的影响规律。（3）研究了小样本地震动记录数量对网壳结构抗震设计需求估计的影响，为减小失效概率的差异，在抗震设计中增加地震动记录数量是需要的，采用7条记录获得的结构失效概率与不考虑小样本数量相差半个数量级。（4）为在受压杆件中充分利用材料的抗拉强度，提出一种新形式的杆件——刚壁气承轴心受压杆件，推导刚壁气承轴心受压杆件的承载力公式，并与薄壁圆管进行比较，表明刚壁气承轴心受压杆件具有很好的承载力，当长细比较大时，优势更加明显。. 通过本项目的研究，丰富了空间网格结构的抗震设计理论，为推动空间网格结构向更大跨度方向发展提供了思路。发表SCI收录论文4篇，EI收录论文1篇，授权发明专利4项，联合培养硕士生2人，在读硕士生1人，指导本科毕业论文2篇。