大跨度轮辐式单双层索网结构施工过程模拟

Simulation of Construction Process for Large-span Wheel-spoke Single-double-layer Cable Net Structures

对于大跨度索网屋架结构,结构刚度主要来自拉索预应力与张拉形成的几何形态,因此,施工张拉过程对结构成型与安全至关重要。作为首创的轮辐式单双层索网结构,乐山奥体中心体育场屋架具有结构形式复杂、两侧索网不对称、施工难度大等特点。对索系屋架结构进行低空低应力组装、整体提升安装、分批成组锚固的3步式施工过程模拟,考察了张拉施工过程中的结构位形与索力变化情况。结果表明,屋架张拉过程中拉索内力、结构位移过渡稳定,单双层索网交界处不平衡力可控,索网体系无失稳风险,屋架整体有足够的施工安全储备。

For large-span cable net roof structures,the structural stiffness primarily comes from the prestress of the cables and the geometric configuration formed by tensioning.Therefore,the construction tensioning process is crucial for the formation and safety of the structure.As an innovative wheel-spoke and single-double-layer cable net structure,the stadium roof of Leshan Olympic Sports Center exhibits characteristics such as complex structural form,asymmetric cable nets on both sides,and high construction difficulty.A three-step construction simulation,involving low-level,low-stress assembly,overall lifting installation,and phased grouping anchoring was conducted for the cable system roof structure.The changes in structural geometry and cable forces during the tensioning process were examined.The results indicate that the internal forces and structural displacements during the roof tensioning process transition smoothly.The imbalanced forces at the junction of the single and double layers of cable nets can be controlled,and the cable net system has no instability risk,the overall roof structure possesses sufficient construction safety reserves.