中横梁对双T梁桥纵梁受力性能影响的数值分析

Numerical analysis of middle cross beam on longitudinal beam of double T-beam bridge

目前我国的装配式T形梁桥除了设置端横梁外,一般还设置中横梁。然而中横梁的设置,不仅会增加梁体预制的复杂度,还会增加现场装配的难度和时间。在工业化建造和快速化施工的背景下,取消中横梁已成为趋势。但装配式双T梁作为开口构件,其扭转性能弱于闭口截面梁,取消中横梁,可能会对梁端支点产生不利影响。现采用空间有限元法,对无中横梁的先张法预应力双T梁桥的力学性能进行了研究,并与增设一道中横梁进行了对比。研究表明,通过合理的设计,在取消中横梁后,双T梁桥的各项力学指标能够满足规范要求,有很好的安全性和耐久性。

At present,the middle cross beam in addition to end cross beam is generally provided in the prefabricated T-shaped girder bridge in our country.However,the setting of middle cross beam will not only increase the complexity of beam prefabrication,but also increase the difficulty and time of field assembly.Under the background of industrial construction and rapid construction,it has become a trend to cancel the middle cross beam.However,the torsion performance of the prefabricated double-T beam as an open member is weaker than that of the closed section beam,and the cancellation of the middle cross beam may have a negative impact on the main girder,especially the beam end.In this paper,the mechanical properties of pretensioned double-T girder bridge without middle cross beam are studied by space finite element method and compared with that of adding one middle cross beam.The research results show that the mechanical properties of the double T-beam bridge can meet the requirements of the code after the cancellation of the middle diaphragm through reasonable design,and it also has good safety and durability.