预应力砼桁架T构桥梁剪力铰及拉压支座病理分析

Pathological analysis on T-frame bridge of prestressed concrete truss shear and tensile and compressive bearing hinge

预应力砼斜拉桁架T构桥是一种较为特殊的桥梁结构形式,综合斜拉、桁架及T形刚构三种结构的受力特点。以洪塘大桥为依托工程,剪力铰和拉压支座作为该桥的特殊构件,经常发生破坏,但是此类桥型工程实例及研究成果较少,桥梁产生病害的机理尚不明确。采用大型有限元软件建立洪塘大桥模型,用单因素和多因素正交试验法分析可能引起病害的因素,如预应力损失、基础不均匀沉降、刚度损失和活载对剪力铰和拉压支座的影响程度,为其设计优化提供有价值的参考和借鉴。

T-frame bridge of prestressed concrete truss is one of the specific forms of bridge structures, inte- grated characteristics of the three structures cable-stayed, truss and T Rigid and mechanical. Based on the re- search of Hongtang Bridge, the author found that shear strategy and tension-compression bearing, as special components of bridge abutment, are frequently damaged, but few examples and research findings of such bridge-engineering are reported, and the damage mechanism is not clear. Hongtang Bridge Model is estab- lished by finite element software to analyze the factors that may cause disease by univariate and multivariate or- thogonal test, such as prestressed loss, uneven foundation settlement, as well as the degree of influence caused by stiffness and loss of live load and shear hinges bearing tension and compression, which provide valu- able reference for its design optimization.