单跨等截面柱门式刚架结构柱计算长度系数研究

Study on Calculating Length Coefficient of Portal Frame Column with Single Span and Equal Section

钢骨架轻型屋面板作用下的门式刚架厂房,在铁路类检修厂房中得到较为广泛的应用。其屋面恒荷载取值通常远高于传统压型钢板门式刚架厂房的荷载取值,由于其自重较大,超出了《门式刚架轻型房屋钢结构技术规范》的适用范围;而应用《钢结构设计标准》对其进行设计时,梁、柱设计截面往往过大,且大多是由构件局部及整体稳定限值的构造要求引起的,造成工程造价的大幅增大。亟需进行相关研究解决以上问题。结合工程实际,采用力学方法,提出了两种柱脚连接方式的刚架柱顶支座刚度及平面内计算长度系数的计算公式。通过数值拟合,得到了近似公式。研究结果表明计算长度系数只与柱脚连接方式、水平弹簧支座刚度、转动弹簧支座刚度有关。研究结果对铁路类门式刚架厂房的设计具有现实的指导意义。

The portal frame workshop with steel frame and light roof plate is widely used in railway maintenance workshop.The constant load value of the roof is usually much higher than that of the traditional pressure steel slatted frame workshop.Due to its large dead weight,it is beyond the applicable scope of the technical specification for steel structure of light house with portal frame.However,when the steel structure design standard is applied to its design,the beam and column design section is often too large,and most of them are caused by the structural requirements of partial and overall stability limits of the members,resulting in a large increase in engineering cost.In this paper,by means of mechanical method,the formulas for calculating the stiffness of column top and the length coefficient in plane of rigid frame connected by two kinds of column legs are put forward.The approximate formula is obtained by numerical fitting.The results show that the calculated length coefficient is only related to the connection mode of column foot,the stiffness of horizontal spring support and the stiffness of rotating spring support.The research results have practical guiding significance for the design of railway portal frame.