预应力混凝土斜交箱梁桥的畸变效应分析

发布时间：2018-05-02 10:45

本文选题：斜交箱梁桥 + 畸变角　；参考：《石家庄铁道大学》2015年硕士论文

【摘要】：箱梁的截面形状是几何可变的,因此在偏载或反对称荷载作用下,箱梁截面不仅产生刚性扭转还会产生随畸变。目前,对于正交箱梁桥的畸变角和畸变应力的理论计算方法,国内外学者进行了大量的研究,并取得了相应的成果。但是有关斜桥的畸变效应研究很少,故本文分析了斜交箱梁桥在静载和动载作用下预应力斜交箱梁桥的畸变效应变化规律。运用大型软件ANSYS分别建立了简支和三跨连续斜交箱梁桥模型。首先,分析了简支和连续斜交箱梁桥自重下的纵向畸变效应并获得最不利截面;随后静力部分建立了一系列箱梁模型,分析参数变化时腹板与顶板交界处的畸变角纵向变化规律;最后动力部分采用车桥耦合模型,其中车辆采用6参数2自由度的1/4车辆模型,主要分析了车辆行驶过程中简支和连续斜交箱梁桥的不利截面在三种不同的行车位置、三种不同轴重、六种不同行车速度等参数变化时的畸变效应变化规律:简支斜交箱梁桥和三跨连续斜交箱梁桥的畸变效应有一定的差异;在简支斜交箱梁桥中,3/4跨截面为畸变效应的不利截面,随着参数的变化,可以看出斜度、行车速度、预应力水平、宽跨比对畸变效应的影响较大;在三跨连续斜交箱梁桥中,各跨的中部截面畸变效应较为明显,不同的参数变化对不利截面的影响存在一定的差异。其中,各跨中部截面畸变角曲线随车速和行车位置不同变化的不是很明显。
[Abstract]:The section shape of box girder is geometric variable, so the section of box girder not only produces rigid torsion but also produces distortion under the action of partial load or antisymmetric load. At present, domestic and foreign scholars have done a lot of research on the theoretical calculation method of the distortion angle and stress of the orthogonal box girder bridge, and have obtained the corresponding results. However, there are few researches on the distortion effect of skew bridge, so the variation law of distortion effect of skew box girder bridge under static and dynamic loads is analyzed in this paper. The models of simply supported and three-span continuous skew box girder bridges are established by using large-scale software ANSYS. Firstly, the longitudinal distortion effect of simply supported and continuous skew box girder bridges under deadweight is analyzed and the most unfavorable section is obtained. Then, a series of box girder models are established in the static part. The longitudinal variation law of the distortion angle at the junction of the web and the roof is analyzed. Finally, the vehicle-bridge coupling model is used in the dynamic part, in which the vehicle adopts a 1 / 4 vehicle model with 6 parameters and 2 degrees of freedom. In this paper, the unfavorable cross sections of simply supported and continuous skew box girder bridges are analyzed in three different driving positions and three different axle loads. There are some differences in the distortion effect between the simply supported skew box girder bridge and the three span continuous skew box girder bridge, and the 3 / 4 span section of the simply supported skew box girder bridge is the unfavorable section of the distortion effect. With the change of parameters, it can be seen that the distortion effect of slope, driving speed, prestress level, width span ratio is greater than that of three-span continuous skew box girder bridge, and the distortion effect of middle section of each span is more obvious in three-span continuous skew box girder bridge. There are some differences in the influence of different parameters on the unfavorable section. Among them, the distortion angle curve of the middle section of each span is not obvious with different speed and driving position.
【学位授予单位】：石家庄铁道大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U441

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