滚石撞击桥墩动力响应试验

发布时间：2019-02-19 13:30

【摘要】：为正确估计滚石撞击山区桥梁结构的动力响应,以中国西部山区中广泛采用的矩形桥墩为对象,利用45°,90°,135°不同高度重力摆锤下落,对3种不同截面尺寸(20cm×20cm,30cm×30cm,40cm×40cm)矩形墩柱进行冲击试验,从动态损伤扩展、墩柱撞击力及墩顶动力响应等方面研究矩形墩柱的冲击响应过程和破坏机理,并将墩柱撞击力时程曲线与中国《公路路基设计规范》(JTG D10—2016)及日本道路公团给出的等效静力撞击力计算公式进行对比和讨论。研究结果表明:冲击荷载作用下,墩柱可能出现整体损伤及局部损伤2种损伤形态,其中局部损伤出现在墩柱撞击区域,主要为剪切裂缝,整体损伤出现在墩底,主要为弯曲裂缝;墩柱整体刚度的提高对撞击区域混凝土局部损伤影响不大,但能减小墩顶位移,增大撞击力峰值;随着重力摆锤下落高度的提高,撞击初始动能越大,墩柱的墩顶位移及撞击力峰值都将增大;中国《公路路基设计规范》撞击力计算公式与试验平均撞击力接近,计算结果偏小,设计不安全,日本道路公团公式的分析结果与实测墩柱撞击力峰值吻合良好,建议工程设计予以采用。
[Abstract]:In order to correctly estimate the dynamic response of the bridge structure in mountainous area with rolling stones, taking the rectangular pier widely used in the mountainous area of western China as the object, using the gravity pendulum drop of 45 掳, 90 掳and 135 掳, three different cross section sizes (20cm 脳 20 cm ~ (10) cm 脳 30 cm) are studied. The impact response process and failure mechanism of rectangular pier columns were studied from the aspects of dynamic damage expansion, impact force and dynamic response of pier top. The time-history curve of impact force of pier column is compared and discussed with the formula of equivalent static impact force given by JTG D10-2016 and Japan Road Gongtuan. The results show that under impact load, there may be two kinds of damage forms: global damage and local damage, in which the local damage occurs in the impact zone of the pier column, mainly in shear cracks, and the whole damage occurs at the bottom of the pier. Bending crack; The increase of the overall stiffness of pier column has little effect on the local damage of concrete in the impact area, but it can reduce the displacement of pier top and increase the peak value of impact force. With the increase of the falling height of gravity pendulum, the greater the initial kinetic energy of impact, the greater the peak value of pier top displacement and impact force. The calculation formula of impact force is close to the average impact force of the test in China, the result is small and the design is unsafe. The analysis result of the Japanese road mass formula is in good agreement with the peak value of the measured impact force of piers. It is suggested that the engineering design be adopted.
【作者单位】：浙江大学宁波理工学院土木与建筑学院;
【基金】：国家自然科学基金项目(51178429) 浙江省自然科学基金项目(LY18E08004) 宁波市科技创新团队项目(2011B81005)
【分类号】：U441.3

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