为确保港珠澳大桥预制埋床式墩台的设计达到受力性能优良及布筋合理的要求,同时明确桥墩失效过程混凝土开裂及裂缝扩展情况及桥墩极限承载能力,采用强化有限元方法(AFEM)对桥墩失效过程进行了模拟分析。从网格分离技术、实体单元退化理论、桥墩中普通钢筋和预应力钢筋模型以及非线性问题处理方法等4个方面对钢筋混凝土结构开裂及破坏分析中的关键问题进行了讨论,建立了通用的钢筋混凝土结构性能分析技术框架;以受力最不利桥墩为对象,对2种配筋模式竖向荷载作用下的墩身非线性受力行为进行了全过程分析,比较了2种不同配筋对桥墩结构性能的影响,明确了混凝土开裂及裂缝扩展特点。结果表明:配筋方案1的混凝土一旦开裂,裂缝就急剧扩展,裂缝从上墩身快速向中墩身发展,出现竖向和横向变形跳跃;对于配筋方案2,当墩顶出现开裂以后,墩身刚度也明显下降,荷载-位移曲线有一个明显转折点,但未出现跳跃式变化,裂缝宽度也较第1种小,极限承载力提高了约10%,桥墩结构性能较方案1有明显改善;计算结果为桥墩结构设计提供了参考依据,同时也表明,基于增强有限元的混凝土结构失效过程分析方法,可考虑结构的空间效应、分析空间破坏形态,具有形式统一、概念简洁等优点,工程适用性强。 In order to ensure that the design of prefabricated pier for Hong Kong-Zhuhai-Macao Bridge meets the requirements of excellent load-bearing performance and reasonable reinforcement, the crack initiation and crack propagation and the ultimate bearing capacity of the piers during the failure of the pier are clarified. The finite element method ) On the pier failure process simulation analysis. The key problems in cracking and failure analysis of reinforced concrete structures are discussed from the aspects of grid separation technology, solid element degeneration theory, common steel bars and prestressed steel bars in bridge piers, and non-linear problem solving methods, and a general Reinforced concrete structure analysis of the technical framework; to force the most unfavorable piers as the object, two kinds of reinforcement mode vertical load of the pier under the non-linear force behavior of the whole process were compared, compared two different reinforcement pairs Bridge pier structural performance, clear concrete crack and crack propagation characteristics. The results show that once the concrete in the reinforcement scheme 1 cracks, the cracks expand rapidly, and the cracks develop rapidly from the upper body to the middle body, resulting in vertical and horizontal deformation and jumping. For the reinforcement scheme 2, when cracking occurs on the top of the pier, The stiffness of the pier body also decreased obviously. There was a clear turning point in the load-displacement curve, but there was no jumping change. The crack width was also smaller than that of the first one and the ultimate bearing capacity increased by about 10%. The structural performance of the pier was obviously improved The results also provide a reference for the design of piers. It also shows that based on the finite element method for analyzing the failure process of concrete structures, the space effect of the structure can be considered, the shape of the space destruction can be analyzed, the form is unified and the concept is concise. Applicability.