对接接头对现代木结构桥梁SLT桥面板性能的影响

 针对现代木结构桥梁应力叠合木(SLT)桥面板性能受其对接接头的影响问题,探讨了Ritter、Crews 的设计方法以及加拿大、美国、欧洲的有关规范,并通过工程实例进行了计算分析。结果表明,对接接头会降低SLT 桥面板的强度及刚度,为了保证结构安全,需要合理设计对接接头的频率与间距,而各种设计方法及规范中,Ritter 设计方法相对安全,目前SLT 桥面板的应用在中国尚处于初期研究阶段,适合采用安全系数较高的Ritter 设计方法;在恒载和活载作用下,SLT 桥面板的挠度安全储备较应力安全储备大,采用Ritter 设计方法时弯曲应力计算值为设计值的69.2%,而挠度计算值为容许值的90.7%,因此在SLT 桥面板的应用设计中要着重考虑满足刚度要求。

Influences of butt joint on the behavior of stressed laminated timber deck of modern timber bridge

For the problem that the behavior of the stress laminated timber (SLT) deck of modern timber bridge is influenced by butt joint, the design methods of Ritter and Crews and the specifications of Canada, Europe and America are discussed, and the calculations contrasted through a practical engineering project. The results show that butt joint may reduce the strength and stiffness of the SLT deck, and that reasonable butt joint frequency and spacing should be considered in order to ensure the safety of the structure. The Ritter's design method is relatively safe among the various kinds of design methods and can meet the specifications. Therefore, it is recommended because the application of SLT deck in China is still in its early stage at present. The SLT deck has a larger emergency capacity of stiffness than that of strength under dead load and live load, the calculated value of bending stress is 69.2% of the design value, and the calculated value of deflection is 90.7% of the permissible value using the Ritter's design method, so the stiffness requirement should have a priority in the design consideration.