论文部分内容阅读
为探讨节段拼装桥墩的抗震性能,设计了一个包含5种不同类型混凝土桥墩的试验方案,其中3种为节段拼装桥墩,其余2种分别为整体现浇钢筋混凝土桥墩和无粘结预应力混凝土桥墩。采用振动台试验方法比较分析了这5种不同构造类型混凝土桥墩的动力特性,损伤的发展过程,接缝的扩展规律,相同加速度激励下的最大位移响应等,总结了不同类型桥墩的地震响应特点和规律。试验结果表明:节段拼装预应力混凝土桥墩的破坏现象主要是塑性铰节段墩底接缝的张开,塑性铰节段墩身没有发生损伤现象,随输入增加,接缝张开程度逐渐增大,表现为明显的摇摆现象。在相同输入下,节段拼装试件的最大位移响应大于同等整体现浇钢筋混凝土试件。耗能钢筋的存在可以增加桥墩的侧向刚度,减小最大位移响应,延缓接缝的张开,增加结构的耗能能力。有粘结预应力筋的存在,使得节段拼装桥墩在较大输入激励下,预应力筋易发生屈服,从而导致位移响应急剧增大。
In order to investigate the seismic performance of the piers with segment assembling, a test scheme including five different types of concrete piers is designed, of which three are piers, and the other two are monolithic cast-in-site reinforced concrete piers and unbonded prestress Concrete pier. The shaking table test method is used to analyze the dynamic characteristics, the development of damage, the expansion law of joints, the maximum displacement response under the same acceleration excitation and so on. The seismic response characteristics of different types of piers are summarized And the law. The experimental results show that the failure phenomenon of prestressed concrete piers with segment assembly is mainly caused by the open joints of the piers at the bottom of the plastic hinge segment. There is no damage to the piers of plastic hinge segments. As the input increases, Large, manifested as obvious swing phenomenon. Under the same input, the maximum displacement response of the segment assembled specimen is greater than the same overall cast-in-place reinforced concrete specimens. The presence of energy-consuming reinforcement can increase the lateral stiffness of the piers, reduce the maximum displacement response, delay the opening of joints, and increase the energy dissipation capacity of the structure. The existence of bonded prestressed tendons makes the prestress tendons tend to yield under the large input excitation of the segment piers, resulting in a sharp increase of the displacement response.