强震下斜交刚构连续梁桥倒塌特性研究

发布时间：2018-11-24 20:06

【摘要】：斜交桥的非对称支承特点使得其在地震作用下更容易遭受倒塌破坏,为探究斜交梁桥在地震倒塌过程中表现出的动态特性,建立一座斜交四跨刚构连续梁桥的精细化空间有限元计算模型,采用显式动力接触算法数值模拟强震下斜交箱梁桥的动态倒塌破坏特性,分析了主梁的不规则位移和梁端的碰撞现象。结果表明,斜交梁桥主梁在三向地震动作用下会发生水平面内旋转,不同地震动下主梁的旋转方向不同,梁体旋转过程中会与桥台发生碰撞,碰撞使得倒塌破坏过程中主梁靠近桥台的相对位移明显小于远离桥台的相对位移。梁端横截面碰撞力呈现不均匀分布,主梁锐角处碰撞力大于钝角处碰撞力,截面中心位置处很少发生碰撞,且碰撞作用会显著影响墩台的破坏顺序。墩台对主梁的碰撞实质上是桥梁下部结构对梁体的动态约束和阻挡限制,是主梁的动态约束边界条件。
[Abstract]:The asymmetric supporting characteristics of skew bridge make it more vulnerable to collapse and damage under earthquake. In order to explore the dynamic characteristics of skew beam bridge in the course of earthquake collapse, A finer spatial finite element model of a skew four-span rigid frame continuous beam bridge is established. The dynamic collapse and failure characteristics of skew box girder bridge under strong earthquake are numerically simulated by explicit dynamic contact algorithm. The irregular displacement of the main beam and the collision at the end of the beam are analyzed. The results show that the main beam of skew beam bridge will rotate in horizontal plane under the action of triaxial ground motion, the rotation direction of the main beam will be different under different ground motion, and the beam body will collide with the abutment during the rotation process. The relative displacement of the main beam near the abutment is obviously smaller than that far away from the abutment. At the end of the beam, the collision force at the sharp angle of the beam is larger than that at the obtuse angle, and the collision at the center of the section rarely occurs, and the collision will significantly affect the damage sequence of the pier and abutment. The collision of pier and abutment to the main beam is essentially the dynamic constraint and barrier restriction of the bridge understructure to the beam body, and is the dynamic constraint boundary condition of the main beam.
【作者单位】：山东建筑大学交通工程学院;
【基金】：国家自然科学基金项目(51178258)
【分类号】：U442.55

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