短語詞組短語pined beam same span 等跨鉸接梁flat beam wide span plank 寬扁梁multiple beam span 多梁橋跨steel beam span 鋼梁跨越beam span depth ratio 跨高比beam under arbitrary span 任意跨距continuous beam with long span 大跨度連續(xù)梁flat beam -wide span plank 寬扁梁span beam 大跨度梁 返回 beam span