高速铁路调跨简支箱梁足尺破坏试验与数值模拟研究

Destructive Experiment and Numerical Simulation of Full Scale Span Adjusting Simply Supported Box Girder of High-speed Railway

为研究高速铁路2300 MPa新型预应力体系32.6 m调跨简支箱梁的承载能力,采用足尺破坏试验方法,对新型调跨简支箱梁施加2.55倍设计弯矩对应的荷载,测试并分析箱梁破坏全过程的整体变形、局部应变、裂缝发展状况;对该新型调跨简支箱梁破坏过程进行数值模拟,提出考虑钢筋三维增强效应的混凝土本构模型,建立足尺度三维非线性有限元模型,解决钢筋混凝土损伤模拟时间成本高、收敛难度大的问题。研究结果表明:该新型调跨简支箱梁在2.55倍设计弯矩作用下未出现严重破坏现象,箱梁依旧具有较高的安全裕度,证明该高速铁路新型箱梁结构体系的合理性与推广使用的可行性。

In order to study the bearing capacity of the 2300 MPa pre-stressed 32.6 m span adjusting simply supported box girder,the destructive experiment and numerical simulation of the newly designed full-scale box girder were completed in this paper to test and analyze the global deformation,local strain and crack development of the new box girder under the 2.55 times the design bending moment.In order to solve the problem of high time cost and difficult convergence of reinforced concrete damage simulation,a concrete constitutive model considering three-dimensional reinforcement effect was proposed.A three-dimensional nonlinear finite element model was established to simulate the entire destructive process of the box girder.Both the experimental and numerical simulation results show that the 32.6 m span adjusting simply supported box girder with the new pre-stressed system does not appear serious damage under the 2.55 times the design bending moment,with a high safety margin,proving the rationality of the structural system and the feasibility of the application of the new designed box girder.