几种常见形式的等效阶梯截面

针对许多平面杆系桥梁分析软件仅提供梯形分块法的截面尺寸输入方式和截面几何特性已知或者有解析表达式的带有曲边的截面不便直接使用梯形分块法的问题，利用桥梁结构平面计算中截面等效的概念．提出了等效算法，构造了节线数不多于6的等效阶梯截面，推导了等效阶梯截面几何要素的一般计算公式．给出了圆形、圆环等几种常用截面形式的不多于6条节线等效阶梯截面尺寸计算的具体而又简捷的公式。

Several Common Equivalent Ladder Sections

Many software for bridge beam structural analysis only supply the input mode of section size for the trapezoidal method, and it causes inconvenience for sections with curved border to apply direct the trapezoidal method, whose geometric characteristics are known or have analytic expressions. Aiming at these, using the concept of section equivalent in bridge structural plane calculation, the author brings forward method of equal effects, creates a kind of equivalent ladder section with no more than 6 partition lines, deduces common formulas of geometric factors of equivalent ladder section, presents full and brief expressions of section size of equivalent ladder sections with no more than 6 partition lines for several common sections such as circle and toroid, widens the applicative field of the trapezoidal method.