新型拱式钢筋混凝土梁桥优化设计方案研究

Study of Optimization Design Scheme for New-Type Hybrid Composite Beam Bridge

拱式钢筋混凝土梁桥(HCB)是近年国际上兴起的一种环保、美观的新型桥梁,国内尚无工程实例。为探索该类桥在国内推广应用的技术可行性,按照我国相关规范针对HCB结构尺寸和配筋方案进行了16m跨径HCB试设计,建立整桥实体有限元模型,研究结构尺寸参数对HCB基本受力性能的影响,指出设计主要控制因素;利用ANSYS优化模块得到优化设计方案,对优化方案的延性进行了研究。结果表明:试设计方案力学性能满足有关规范要求,设计控制因素包括拱顶内力和主梁挠度;优化后混凝土用量相比同跨径标准预应力空心板梁可节约33%,表明该类桥梁可行合理;HCB延性与底部水平抗拉钢筋数量和拱肋纵筋数量正相关。

The hybrid composite beam （HCB） bridge is a new-type of bridge thaenvironment-friendly and aesthetically pleasing, but there has no actual engineering practice inChina. To explore the technical viability of the application of HCB in China, the trial design 16 m long HCB bridge was carried out in accordance with the structural dimension and reinforce-ment layout of HCB stipulated in the Chinese specification. The solid finite element model of the o-verall bridge was established, to study the influence of the structural dimension parameters on the basic load bearing capacity of the HCB bridge and to find out the key control factors in the design. And the optimization module of the ANSYS software was used to gain the optimized design scheme and to study the ductilityof the optimized scheme. The results of the studyshow that the load bearing capacity of the bridge in the trial design can meet the relevant requirements in and the design control factors include the internal force in the arch crown and the deflection main girder. After optimization, the amount of concrete used saved 33% ,compared with cal prestressed concrete hollow plate girder with the same span length, confirming the applicability and rationality of the bridge of such type. The ductility of HCB is directly proportional to the a-mount of horizontal tensile reinforcement in the base of the beam and the longitudinal reinforce-ment in the arch rib.