空心高墩施工阶段主要受力性能分析

发布时间：2018-05-29 23:17

本文选题：空心高墩 + 计算长度　；参考：《长安大学》2015年硕士论文

【摘要】：随着我国交通基础设施建设的迅速发展,各类公路、铁路桥梁如雨后春笋般出现。在山区及河流流经地区需要修建大量高墩桥梁,而空心桥墩因其优良的结构性能和较低的造价得到广泛使用。与此同时我国的桥梁施工技术也取得了巨大进步,大型造桥机械的使用使得大型桥梁的建设更加经济、快捷。本文以某铁路桥梁造桥机施工过程为例,通过公式和有限元方法研究空心桥墩在造桥机施工过程中的主要受力情况。其中包括以下几方面的研究:(1)分别用铁摩辛柯能量法和有限元法求解了桥墩在施工过程中墩顶不同约束条件下的屈曲荷载,并计算了桥墩在相应荷载下的弯矩增大系数,讨论分析了剪切变形和桥墩上下两端实体部分对临界屈曲荷载的影响。(2)对墩帽以下的墩身部分按照受压杆件分析其受力,假设桥墩墩帽以下部分满足平截面假定,并据此计算绘制了墩身两个不利截面的轴力弯矩相关曲线。(3)对墩帽部分应力复杂区域主要采用有限元计算方法计算分析了造桥机施工过程中局压的几种最不利工况,并用规范公式计算对比。通过分析表明剪切变形和桥墩墩实体部分对桥墩弹性屈曲荷载影响较小,可以忽略不计;空心墩正截面承载能力满足要求,且富裕很多;施工过程中墩帽部分局部拉应力超过混凝土极限拉应力,墩帽顶部将会出现裂缝。实际施工时需加大造桥机与墩帽顶部的受压面积等措施以解决局部应力过大的问题。
[Abstract]:With the rapid development of transportation infrastructure in China, all kinds of highways and railway bridges are springing up. A large number of bridges with high piers need to be built in mountainous areas and areas where rivers flow, while hollow piers are widely used because of their excellent structural properties and low cost. At the same time, great progress has been made in the technology of bridge construction in our country. The use of large-scale bridge construction machinery makes the construction of large bridge more economical and faster. Taking the construction process of a railway bridge maker as an example, this paper studies the main force situation of hollow pier in the construction process of bridge construction machine through formula and finite element method. The research includes the following aspects: (1) the buckling load of pier under different constraint conditions at the top of pier during construction is solved by using Temoco energy method and finite element method respectively, and the moment increasing coefficient of pier under corresponding load is calculated. The influence of shear deformation and the solid parts of the upper and lower ends of the pier on the critical buckling load is discussed and analyzed. The stress on the pier body below the pier cap is analyzed according to the compression member. The assumption that the section below the pier cap satisfies the assumption of the plane section is assumed. Based on this, the axial bending moment correlation curve of two unfavorable sections of the pier is calculated and drawn. The finite element method is mainly used to calculate and analyze the most disadvantageous conditions of local pressure during the construction of the bridge construction machine for the complex region of the partial stress of the pier cap. The standard formula is used to calculate and contrast. The analysis shows that the shear deformation and the solid part of the pier have little influence on the elastic buckling load of the pier, which can be ignored, and the normal section bearing capacity of the hollow pier meets the requirements and is much richer. During construction, the partial tensile stress of pier cap exceeds the limit tensile stress of concrete, and cracks will appear at the top of pier cap. In order to solve the problem of excessive local stress, it is necessary to increase the area under pressure at the top of bridge maker and pier cap in actual construction.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U441;U445.559

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