基于抗连续倒塌性能的张弦梁结构撑杆构型与数值验证

Progressive collapse resistance-based strut configurations of beam string structure and its numerical verification

针对传统张弦梁结构冗余度低、易发生连续性倒塌的特点,引入变换荷载路径法改进撑杆构型,提出了一种交叉撑杆构型的张弦梁结构体系。以某体育馆张弦梁结构为原型,建立了新型撑杆构型的张弦梁结构基准模型。通过优化撑杆交叉角度、交叉节点位置等参数,得到了多个具有新型撑杆构型的张弦梁结构模型,并采用有限元方法对其承载力与抗连续倒塌性能进行了分析。结果表明:经合理设计,新型撑杆构型的张弦梁结构与传统张弦梁结构在刚度、承载力等方面较为接近,且新型撑杆构型的张弦梁结构承载力与撑杆交叉节点的位置有关;当中间索失效时,下撑杆能代替失效索为结构提供有效的传力路径,且交叉角度较大时新型撑杆构型的张弦梁结构抗连续倒塌性能更好;当边索失效时,交叉撑杆构型的张弦梁结构的竖向位移均较传统张弦梁结构的大幅减小,其抗连续倒塌性能更加优良。

Due to the low redundancy and incidental progressive collapse for traditional beam string structure(TBSS),the strut configuration was improved by introducing the alternate load path method,and a beam string structure system with novel strut configuration was proposed.A benchmark model of the beam string structure with the novel strut configuration was established based on the structural scenario of a stadium.Several beam string structure models with novel strut configuration were obtained through optimizing the crossing angle of strut and its location of crossing joints,and the bearing capacity and progressive collapse performance were analyzed with the finite element method.The results show that when a proper design is applied,the stiffness and the bearing capacity between the novel structure and the traditional one are almost the same,and the bearing capacity is dependent of the location of strut crossings for the novel structure.For the failure of intermediate cable,the lower strut can act as an alternate of the failed cable to provide an effective force transferring path for the novel structure,and the progressive collapse resistance performance is better for the novel structure with a larger angle of the crossing struts.For the failure of the side cable,the vertical displacement of the novel structure is largely reduced compared with that of the traditional one,and the novel structure can achieve an even better resistance of progressive collapse.