混凝土填充率对STS管幕结构抗弯性能的影响研究

The Influence of Concrete Filling Rate on the Flexural Performance of STS Structure

STS管幕结构是由多根钢管并排组成具有强效横向连接的、辅助地铁暗挖施工的一种支护结构,具有安全、高效的特点。但在施工过程中难以保证混凝土的填充率,给该结构的整体受力性能带来了安全隐患,为推进STS管幕结构的应用,采用数值模拟的方法分析了混凝土不同填充类型和填充率对管幕结构抗弯承载力及刚度的影响。结果表明:管内中轴线以上及管间受压区从上至下20%高度范围内的混凝土对管幕结构的承载能力起主导作用,因此建议在实际工程中保证管内填满混凝土,同时确保管间压区混凝土填充率至少达到20%以上。

Steel Tube Slab(STS)structure is a kind of pre supporting structure of auxiliary subway construction with a strong lateral connection of multiple steel pipes,which has the characteristics of safety and high efficiency.However,it is difficult to ensure the filling rate of concrete during the construction process,which brings potential safety hazards to the overall mechanical performance of the structure.To promote the application of the STS structure,the impact of the concrete filling rate on the tube roof structure is deeply analyzed.In the study of concrete filling rate,the influence of different filling types and filling rate of concrete on the flexural capacity and stiffness of tube roof structure is analyzed by numerical simulation.The results show that the concrete above the middle axis in tube and the compression concrete within the 20%height range from top to bottom between the tubes are the main influence area.It is recommended to ensure the concrete filling rate 100%in the tube,and ensure that the concrete filling rate of the compression zone between the tubes is at least 20%or more.