墩高渐变的多联桥梁下部结构抗震配筋设计方法研究

Research on Seismic Reinforcement Design Method for Substructures of Multi-span Bridges with Gradually Changing Pier Heights

摘要:

为研究上下部结构形式一致、墩高渐变的多联桥梁在地震作用下的内力响应特点及规律，从而优化结构的抗震设计，以唐山地区某座城市桥梁为例，通过建立的三维有限元模型对其进行抗震计算，重点归纳探讨了高墩和矮墩的优势和劣势。在此基础上，提出了“先定义临界墩高，再以此划分高墩和矮墩；在E2地震作用下允许高墩进入塑性、矮墩保持弹性”的设计思路，并按此思路对案例工程进行了计算和配筋设计。结果表明，所提出的设计思路具有较高实用性，可有效减少配筋量和计算工作量，兼顾结构的安全性和经济性，可为类似多联桥梁抗震设计提供参考。

Abstract:

To study the internal force response characteristics and patterns of multi-span bridges with consistent superstructure and substructure forms and gradually changing pier heights under seismic action, the structural seismic design is optimized. Taking an urban bridge in Tangshan as an example, the seismic calculation is carried out through the established three-dimensional finite element model, and the advantages and disadvantages of high piers and low piers are mainly summarized and discussed. On this basis, the design concept of “first defining the critical pier height, and then classifying the high piers and low piers based on this, and allowing high piers to enter plasticity and low piers to maintain elasticity under the action of the E2 earthquake” is proposed. And based on this thought, the calculation and reinforcement design of the case project are carried out. The results demonstrate that the proposed design concept has the higher practicality, can effectively reduce the reinforcement quantities and computational workload, and take into account both the safety and economy of the structure, which can provide the reference for seismic design of similar multi-span bridges.