【作者】 梁田； 董军；

【Author】 TIAN Liang , *JUN Dong (School of Civil Engineering and Traffic Engineering, Beijing University of Civil Engineering and Architecture, Beijing, 100044, P.R. China)

【机构】 北京建筑工程学院；

【摘要】 曲线矮塔斜拉桥作为一种新兴的桥型在山区得到了广泛的应用,其箱型主梁不仅受轴向压,还承担着相当部分的弯矩和剪力。曲率的存在使得其受力更加复杂,且箱梁宽度的增大导致剪力滞效应严重。本文以龙井河大桥为研究背景,采用有限元理论,通过建立三维实体空间有限元模型,分析该桥主梁在成桥阶段预应力作用下曲线箱梁顶底板正应力分布及其剪力滞效应。研究结果表明施加预应力后,各控制点压应力有所增大,且纵向预应力的合理设置在一定程度上削弱了剪力滞效应引起的应力不均匀分布程度。部分截面顶板最大应力出现在翼缘悬臂端,集中荷载作用位置附近存在明显的剪力滞效应。曲线桥通常内径一侧剪力滞系数略大于外径一侧。按正、负剪力滞和最大剪力滞系数无法准确描述复杂主梁截面的剪力滞效应。更多还原

【Abstract】 The extradosed cable-stayed curved bridge is widely used in mountainous area. The existence of curvature makes the force state more complex and the broadening of box girder lead to serious shear lag effect. Based on the engineering background of Longjing River Bridge, the positive stress distribution and shear lag effect in top and bottom slab of the curved box girder under action of prestressing force are studied. It indicates that the compressive stress of each control points increase under the action of prestressing force, but a reasonable arrangement of longitudinal prestress would weaken the shear lag effect. Generally the shear lag coefficient of the inner diameter side is greater than that of outer diameter side to the curved bridge, and the shear lag effect is significant where loaded with concentrate force. It cannot describe the shear lag effect of a complex girder exactly with only positive, negative or maximum shear lag coefficient.更多还原