【作者】 蒋丹； 陈旭； 李建中；

【Author】 JIAN Dan;CHEN Xu;LI Jian-zhong;Department of bridge engineering, School of civil engineering, Tongji University;

【机构】 同济大学土木工程学院桥梁工程系；

【摘要】 双柱式高墩桥梁广泛存在于我国西部高地震烈度山区,但目前尚无针对墩柱间横系梁的成熟设计方案。实际工程中通常默认系梁沿墩高均匀布置,再由工程师根据设计经验和施工条件确定系梁数量;该过程存在较大的随意性,无法保证其在地震等极端荷载工况下的安全性与经济性。为此,本文基于多振型反应谱结构地震响应简化分析方法,针对双柱式高墩提出了一种高效抗震优化设计方法,能够在面对不同抗震性能目标的情况下,快速求得横系梁布置的最优方案。以西南山区某典型双柱式高墩为背景,首先通过有限元模型非线性时程结果验证了简化分析方法的有效性;随后依照本文所提出的优化设计流程得到了分别以最小化墩柱弯矩和剪力为设计目标的横系梁最优布置方案;将该最优布置结果与现有研究成果进行比较,验证了所提优化设计方法在此类优问题上的可行性和高效性。结果表明所提出的优化设计方法不仅能够得到与现有方法相似的横系梁布置方案,同时将设计耗时从约17小时缩减至约1小时,具有应用于实际设计的潜力。更多还原

【Abstract】 Double-column tall pier bridges are widely prevalent in the high seismic intensity mountainous regions of western China. However, no sophisticated design method is provided for this type of tall piers,especially the distribution pattern of link beams between the two columns to date. In current engineering practice,the link beams are generally assumed locating along the pier height uniformly, and the detailed number of link beams(i.e., the distance between adjacent ones) is determined based on the engineer’s design experience and construction conditions. The results from this approach significantly depends on the subjective judgement of designers, which thus may not able to guarantee the safety and cost-effectiveness of the structure under extreme loading conditions such as earthquakes. In this regard, this paper proposes an efficient seismic optimization design method based on a simplified multi-mode response spectral(MRS) seismic analysis method. This proposed method allows for the rapid determination of the optimal deployment of link beams considering various seismic performance objectives. Taking a typical double-column tall pier bent in the southwestern mountainous region as a case study, the effectiveness of the simplified MRS analysis method is first validated through comparing the results with those from nonlinear time history analyses of refined finite element models. Subsequently, employing the design process proposed in this paper, optimal link beams deployments are determined with the design objectives of minimizing pier bending moments and shear forces. A comparison of the obtained optimal deployment with existing research results validates the feasibility and efficiency of the proposed optimization design method for such problems. The results indicate that while yielding link beams deployments similar to existing methods, the proposed optimization method substantially reduces the time consumption from approximately 17 hours to around 1 hour, demonstrating its potential for practical application in design.更多还原