论文部分内容阅读
通过某城市地铁高架试验段槽形梁桥足尺模型破坏试验,测定结构的极限承载能力,研究其空间受力变形特性及破坏特征。试验结果表明,结构在正常使用和极限状态下的极限荷载分别为设计荷载的1.68和3.0倍,具有足够的安全系数。三维有限元数值计算结果表明,底板存在剪力滞后现象,越接近梁端愈明显。底板纵向剪应力最大值出现在梁端附近截面底板与腹板相交处,支座脱空效应对脱空支座位置的底板应力影响较大,设计中需对梁端进行局部加强处理。跨中截面腹板出现拉应力,最大可达0.91 MPa,设计中应考虑设置一定的竖向抗拉钢筋,防止裂缝产生。
Through the failure test of the full scale model of the trough girder bridge in a metro viaduct test section of a city, the ultimate bearing capacity of the structure is measured and the space deformation characteristics and failure characteristics are studied. The test results show that the ultimate load of the structure under normal use and at the limit state are 1.68 and 3.0 times of the designed load, respectively, with sufficient safety factor. The results of three-dimensional finite element numerical calculation show that there is shear lag in the bottom plate, and the closer it is to the beam end, the more obvious it is. The maximum longitudinal shear stress of the bottom plate appears at the intersection of the bottom plate and the web near the end of the beam, and the effect of the void of the support on the bottom plate stress at the position of the vacant bearing seat is large. Local strengthening of the beam ends is required in the design. Tensile stress occurs across the cross-section web, up to 0.91 MPa. Design should consider setting a certain vertical tensile reinforcement to prevent cracks.