关键词: 桥梁工程；组合梁斜拉桥；辅助墩；综合评价法；最佳合理位置

Abstract: In order to study the influence of auxiliary pier position on the internal force of composite girder cable-stayed bridge, a composite girder cable-stayed bridge with a span of 1380m in Hubei province was taken as the object. 9 kinds of auxiliary pier position schemes were designed and finite element models were established respectively. 7 key indexes were selected, including the stress amplitude of the lower edge of the steel main girder, the stress amplitude of the upper edge of the concrete slab, the vertical deformation amplitude of the main girder, the stress amplitude of the stay cable, the bending moment amplitude of the main tower root, the bending moment amplitude of the lower beam of the main tower, and the bending moment amplitude of the tower column in the main tower. The internal forces of the 9 scheme models were compared and analyzed, and the reasonable location range of the auxiliary pier was obtained according to a single index. Using the comprehensive evaluation method of variation coefficient and standard score method, based on the principle of regression, the reasonable location of auxiliary pier for comprehensive evaluation of all indicators was determined. The results show that: for the stress amplitude of the composite girder, vertical deformation amplitude of composite girder, stress amplitude of stay cable and bending moment amplitude of main tower, the reasonable location range of the auxiliary pier is 0.230L~0.320L, 0.300L~0.320L, 0.275L~0.320L and 0.360L ~0.410L. Considering all indicators comprehensively, the optimal reasonable location of the auxiliary pier of the composite girder cable-stayed bridge is 0.285L away from the side pier (L is the side span).

Key words: bridge engineering; composite girder cable-stayed bridge; auxiliary pier; comprehensive evaluation method; optimum reasonable location