多重四边形环索-张弦梁屋盖拉索张拉施工过程监测及数值模拟分析

Construction Monitoring and Numerical Simulation of Multiple Square Loops-string Dome

为了研究四边环索-张弦梁屋盖在索力张拉时的变化规律,以福州奥体中心体育馆屋盖为工程背景,实时监测索力张拉过程中拉索索力、构件应变及屋盖变形等关键响应.监测结果表明,张拉各重四边形环索可以使屋盖的挠度显著减小;然而,张拉张弦索,会产生一定的"卸载"作用,使得屋盖挠度略有增加,预应力张拉完成后,整个屋盖结竖向刚度显著增大,屋盖挠度减小124mm.各阶段索力张拉过程中,索力及杆件应力均在安全许可范围内.同时,建立空间有限元分析模型,定义非线性阶段施工工况,采用短链杆的温降收缩模拟实际各级索力张拉过程.数值模拟结果与实测结果吻合较好,说明文中建立的数值模型可以较准确地模拟多重环索-张弦穹支屋盖在索力张拉过程中的响应.

In order to study the mechanical characteristic of Multiple Square Loops-String Dome(MSLSD),Fuzhou Olympics Gymnasium is taken as the research background in this paper,which is the first MSLSD project in China.Tension force,sections stress and displacement of the MSLSD under each construction process are monitored.The measured data indicate that tensioning cables of Square Loops can reduce the deflection significantly and improve vertical stiffness of roof.However,the tensioning cables of beam strings increase the roof deflection slightly,which acts as unloading effect.In the end,the vertical stiffness of MSLSD roof increases significantly,and vertical deflection is enhanced by 124 mm after all prestress constructions.For each prestress construction stage,the construction monitored values of cables tension forces and sections stresses are within the safety range.Meanwhile,the 3Dfinite-element model of MSLSD is established.In the model,the prestress constructions are simulated by temperature shrinkage of special link elements.The numerical results match well with monitor data,which validates the numerical model.