不同边界下钢筋混凝土梁桥的非线性响应

NONLINEAR RESPONSES OF THE REINFORCED CONCRETE BEAM BRIDGE UNDER DIFFERENT BOUNDARY CONDITIONS

本文针对钢筋混凝土梁桥,建立了结构的分层单元计算模型并研究了非线性响应。推导了混凝土Owen双参数准则,并根据混凝土单向压缩试验和双向等压试验进行了参数标定,得出了实用的屈服准则表达式。建立了三种边界条件下的计算模型,通过计算分析可知,应用铰支边界条件和简支边界条件,计算结果与试验数据偏离程度较大,均不能正确地评估桥梁结构承载能力;而在修正边界条件下,梁体跨中挠度的计算结果与试验数据吻合程度良好,故在进行梁桥结构响应分析时应正确考虑其边界条件。本文研究结论可供工程设计参考。

A layered element model of the structure is established and the nonlinear response is studied for the RC bridge in this paper. The Owen two-parameter criterion of concrete is deduced. According to the unidirectional compression test and bidirectional isostatic compression test, the parameters are calibrated, and the practical expression of yield criterion is obtained. The calculation model under three kinds of boundary conditions is established. Through calculation and analysis, it can he seen that the application of the boundary conditions of hinge and simple support, the deviation of the calcu- lated results from the test data is quite large, and the carrying capacity of the bridge can not be cor- rectly evaluated. Under the boundary conditions, the calculation results of midspan deflection of the beam body are in good agreement with the experimental data, so the boundary conditions of the beam bridge should be correctly considered in the structural response analysis of the beam bridge. The conclusion of this paper is available for engineering design reference.