高速铁路48 m跨度超高性能混凝土简支梁设计及抗弯性能试验研究

利用超高性能混凝土设计建造桥梁可使结构尺寸更加纤细,能将48 m跨度简支梁质量控制在约850 t以实现整孔运架。本文对48 m跨度超高性能混凝土简支梁设计方案进行静力、动力计算及稳定性分析,并通过与模型梁试验结果的对比,验证超高性能混凝土箱梁设计的合理性及结构受力特征。研究结果表明:推荐的48 m跨度超高性能混凝土简支梁设计方案可实现整孔运架;所采用的设计参数和计算方法合理,开裂前超高性能混凝土梁为弹性工作状态,理论计算结果与试验结果较吻合,破坏荷载作用下梁体安全;超高性能混凝土塑性修正系数应依据具体试验取值,无试验数据时可采用本文试验数据1. 5。

Design on 48 m Span UHPC Simply-supported Girder of High Speed Railway and Experimental Study on Its Flexural Behavior

The bridge using Ultra-high performance concrete may be more slender.The weight of the 48 m UHPC simply supported beam may be controlled within 850 t,leading to integral prefabrication and erection.In this paper,the calculation of static,dynamic and stability of 48 m UHPC simply-supported girder is conducted.The rationality of UHPC box girder design method and structural stress characteristics are verif ied by comparing with model beam test results.The results show that the design scheme of 48 m UHPC simply supported beam recommended in this paper may lead to integral prefabrication and erection.The applied design parameters and the calculation method are rational.The UHPC beam is in elastic state prior to cracking.The theoretical calculation is in good agreement with the test.The beam is safe under failure load.The plastic correction coeff icient of UHPC should be selected according to the specif ic test data.If no test data is available,1.5 suggested in this paper may be used.