大跨双向张弦结构不平衡支撑式滑移技术研究
Research on Unbalanced Support Sliding Technology of Long-span ？？Bidirectional Beam String Structure

针对大跨双向张弦结构提出一种滑移施工方法――不平衡支撑式滑移施工技术，即在施工过程中，通过对索施加合适的预应力，增加结构原有支座的竖向反力，弱化中间滑道临时支撑。基于不平衡支撑式滑移施工技术，以国家体育馆为例建立模型，分析不同索初始索力下关键杆件应力、关键点竖向位移、多滑道支撑的支座反力变化等，探讨大跨双向张弦结构不平衡滑移施工的可行性。研究结果表明：在保证结构安全稳定的前提下，选择适当的索初始索力，可以弱化结构中间临时支撑，减少临时支撑及其下部基础的造价，进而降低滑移施工总成本。
The authors presented a new method of sliding construction ― the technology of unbalanced support sliding construction, which increased the vertical reaction forces of the original bearing reaction and weakened the middle sliding temporary supports through imposing appropriate pre？？stress on cables during construction. Taking the National Stadium as an example, the stress of different key bars with different pre？？stress imposing on the cable, vertical displacement of certain key points, and reaction force of support, etc,were analyzed. Moreover, the possibility of unbalanced sliding construction for long？？span bidirectional beam string structure was discussed. The study results show that the middle sliding temporary supports can be weakened, and the amount of intermediate temporary supports for steel under the premise of ensuring structural safety can be reduced. Furthermore, the total costs of sliding construction will reduce