在相同技术条件下,利用有限元技术对比分析多种尺寸参数的主梁结构,以量化同跨度不同尺寸参数和不同跨度相同尺寸参数下主梁的刚度变化程度。通过分析和探讨,提出了尺寸参数对主梁刚度的影响趋势,并提取了相同技术条件下的不同主梁结构的性能量化指标,为主梁的改造和优化设计、降成本及相应标准拟定与修正提供重要理论和数据依据。“,”In this paper,several sizes of main girder structure are analyzed comparatively by finite element technology and quantified stiffness variation under the same conditions.Through the analysis and discussion,finds the effect tendency of parameters on the girder stiffness,and extracting the performance index from different girder in the same technology conditions which can offer important theoretical and data idea for girder modification,optimization design,cost reduction and corresponding standard formulation.