main rib meaning in English

主肋骨

The seperated pair of main ribs section was made up by bridge panel and girder , because its construction is convenient , used widely in the prestressing force concrete cable - stay bridge of large span
回答：分离式双主肋截面是由桥面板与边主梁组合而成，由于其施工方便，在大跨度预应力混凝土斜拉桥中得到广泛应用。
Modify above model along with altering structural form or the constitution of the bridge , such as different standard , steel ratio , steel pipe diameter , concrete module , brace allocation , the length of concrete of the main ribs , suspending pole mode and cable local vibrations , calculate the variety of dynamic character , analyze this factors which will affect . 2
对斜拉拱桥自振特性进行参数分析,分别考虑了不同规范、含钢率、拱肋钢管直径、混凝土弹性模量、横撑布置、拱肋段混凝土长度、吊杆形式对自振特性的影响,最后考虑了斜拉索局部振动对自振特性的影响。