【作者】 李军；

【导师】 亓兴军；

【作者基本信息】 山东建筑大学 ， 桥梁与隧道工程， 2016， 硕士

【摘要】 斜交梁桥由于其适应路线走向、节约成本等优势而广泛存在于基础设施建设中。新2015版《中国地震动参数区划图》将于2016年6月1日开始实施,因此许多斜交梁桥已经满足不了当前阶段的抗震要求,需要进行减震加固。本文以一座斜度为30°的三跨连续斜交箱梁桥为研究对象,重点分析了地震作用下支座的动力响应和粘滞阻尼器在不同布置方案和阻尼器参数下对桥梁的减震效果,同时探讨了粘滞阻尼器与拉索组合减震措施下的桥梁地震响应及基础类型、宽跨比等桥梁参数对减震效果的影响,主要结论如下：1.横桥向水平地震剪力主要由桥台处支座承担,相对桥墩处支座,桥梁设计中桥台处支座型号较小,桥台处支座易发生屈服。对斜交梁桥进行强震地震响应分析时,需要考虑桥台支座的屈服效应。2.桥台处添加粘滞阻尼器的减震效果要明显优于桥墩处添加粘滞阻尼器的减震效果。采用桥台处设置阻尼器的合理方案时,阻尼器不仅对弯矩和位移有很好的减震效果,还对碰撞、墩底扭矩、主梁平面旋转等有很好的改善作用,但是对桥台处支座屈服影响不大,即添加阻尼器后桥台处支座仍发生屈服破坏。频谱成分不同的地震波对粘滞阻尼器减震效果影响较大,本文中合成波的减震效果要明显好于Taft波。3.采用拉索与阻尼器的组合减震措施时,虽然拉索会产生拉力,但对固定墩内力改善较小,桥台处支座仍发生屈服破坏,与桥台处添加粘滞阻尼器方案对比,未达到预期的更好效果。4.罕遇地震下桥梁墩柱进入塑性状态会显著降低结构内力,在桥台处添加阻尼器可以明显降低固定墩墩底截面曲率,降低地震对结构的损伤。5.不管是否考虑“碰撞约束”,墩底固结工况都会比桩土相互作用工况的结构内力增大、位移减小。粘滞阻尼器在桩土相互作用工况下的减震效果优于墩底固结工况。相同地震动作用下两种工况减震后的梁端纵向最大位移非常接近,粘滞阻尼器具有很好的普适性。6.宽箱梁桥与窄箱梁桥的最大碰撞力均发生在锐角处,且宽桥的碰撞力大于窄桥。跨径相同的宽箱梁桥在地震下的纵桥向位移响应要明显大于窄箱梁桥,粘滞阻尼器对宽箱梁桥的减震效果要略优于对窄箱梁桥的减震效果。更多还原

【Abstract】 Due to the advantages of route trend and cost saving, skew bridges widely exist in the construction of infrastructure. The new 《China seismic ground motion parameter zonation)) will be implemented in June 1,2016. Many of the skew bridge already can’t satisfy the seismic requirements at the present stage, so it need to be strengthened. In view of the less research on vibration reduction and seismic reinforcement of medium and small span skew girder bridge, therefore, this paper which chooses a slope for 30 degrees of three span continuous skew box girder bridge as the research object, focus on the analysis of dynamic response of support under earthquake and the vibration reduction effect of viscous dampers under different layout scheme and damper parameters. At the same time, the seismic response of the bridge with the combined vibration reduction measures of viscous damper and cable, the damping effect of bridge parameters such as foundation type, width span ratio, are all discussed. The main results are as follows:Result OneThe cross horizontal earthquake shear is mainly composed of the abutment bearing. Compared with the bearing on pier, the bearing model of the abutment is small, so yield bearing usually happen at the abutment yield easily. The abutment bearing yield effect of the skew girder bridge under the analysis of strong earthquake response need to be considered.Result TwoThe damping effect of the damper added in the abutment significantly is better than the damping effect of the damper added in bridge pier. When we adopt the reasonable scheme of damper that set at the abutment, the damper has good shock absorption rate not only to the bending moment and displacement, and also have very good improvement effect to the collision, torque, girder plane rotation etc. For bearing yield, the damper has a minimal effect, namely the bearing yield after adding damper on the abutment still occur. The seismic wave with different frequency spectrum has a great influence on the damping effect of the viscous damper. In this paper, the damping effect of the synthetic wave is better than the damping effect of the Taft wave.Result ThreeConsidering the damping effect with the cable and damper, although the cable can produce force, the influence on the internal forces of the fixed piers is very small, and the cable can not meet the expected effect that contrasted with the scheme of damper that set at the abutment.Result FourThe bridge pier under the rare earthquake that enters the plastic state will significantly reduce the internal force. The damper that set in abutment can significantly reduce the curvature of the fixed pier bottom section and reduce earthquake damage.Result FiveNo matter whether or not to consider the "collision constraint", in the consolidation conditions of the pier bottom,the internal force of the structure will increase, and the displacement will response. The damping effect of viscous damper in consideration of pile and soil interaction is better than in the consolidation condition of the pier bottom. Under the same ground motion, the longitudinal maximum displacement of the beam end in the two working conditions is very close, and the viscous damper has a good universality.Result SixThe maximum collision force of wide box girder bridge and narrow box girder bridge occurred in the narrow angle, and the collision force of wide box girder bridge is greater than that of the narrow box girder bridge. The displacement response of the longitudinal bridge under the same span is much larger than that of the narrow box girder bridge. The damping effect of wide box girder bridge with viscous dampers is slightly better than that of the narrow box girder bridge.更多还原