预应力混凝土超静定结构侧向约束的影响分析

发布时间：2018-03-28 17:51

本文选题：预应力侧向约束　切入点：变形协调　出处：《哈尔滨工程大学》2014年硕士论文

【摘要】：预应力技术广泛应用于大跨度超静定混凝土结构中。张拉预应力筋时,由于超静定结构中柱、墙等竖向构件具有较大的抗侧刚度,会对水平构件产生侧向约束。若不考虑侧向约束的影响,会使水平构件承载力的理论分析值大于实际值,从而带来安全隐患。因此对预应力混凝土超静定结构的侧向约束分析具有重要的理论意义和应用价值。本文首先对超静定混凝土结构的预应力效应进行分析,并依据新规范给出计算预应力损失的程序框图;其次通过两种方法推导超静定结构侧向约束的计算公式:一是不考虑转角,依据变形协调条件;二是忽略轴向变形,考虑柱端转角,利用矩阵位移法及D值法的相关知识,分别推导了单层单跨结构、单层双跨结构和单跨双层结构的侧向约束影响系数:最后通过SAP2000有限元软件对列举的工程实例及框架梁侧向约束影响因素进行模拟分析,得到以下结论:1.从对工程实例中框架梁侧向约束的数值模拟结果可知,有限元数值分析结果与理论计算结果相差不大,与变形协调法推导的理论值更为接近,说明在分析超静定结构侧向约束影响时,由于柱端转角很小,可以忽略其影响进行计算。2.从侧向约束影响因素的数值模拟结果可知,随着梁柱线刚度比的逐渐减小、框架结构跨数的逐渐增加、预应力筋偏心距的逐渐减小,框架梁的侧向约束损失值逐渐增大,而预加力对侧向约束损失的影响很小,同时预应力筋的张拉施工方案对侧向约束损失也有一定影响。3.通过有限元分析,提出从增大梁柱线刚度比、减小框架结构的跨数、合理选择预应力筋施工张拉顺序和通过构造措施四个方面减少超静定结构的侧向约束损失。
[Abstract]:Pre-stress technology is widely used in long-span statically indeterminate concrete structures. When tensioning prestressed tendons, vertical members such as walls have larger lateral stiffness due to columns in statically indeterminate structures. If the influence of lateral constraint is not taken into account, the theoretical analysis value of the horizontal member bearing capacity will be greater than the actual value. Therefore, the lateral constraint analysis of prestressed concrete statically indeterminate structure has important theoretical significance and application value. In this paper, the prestress effect of statically indeterminate concrete structure is analyzed. According to the new code, the program block diagram for calculating the loss of prestress is given. Secondly, the formula of lateral constraint of statically indeterminate structure is deduced by two methods: one is not considering rotation angle, the other is neglecting the axial deformation. Considering the angle of column tip, using the knowledge of matrix displacement method and D value method, the single-story single-span structure is derived respectively. The influence coefficient of lateral constraint of single-story double-span structure and single-span double-layer structure is analyzed. Finally, the engineering examples and the factors affecting the lateral constraint of frame beam are simulated and analyzed by SAP2000 finite element software. The following conclusions are obtained: 1. From the numerical simulation results of the lateral constraints of frame beams in engineering examples, it can be seen that the results of finite element numerical analysis are not different from the results of theoretical calculation, and are closer to the theoretical values derived by the deformation coordination method. The results show that in the analysis of lateral constraints of statically indeterminate structures, due to the small corner of column tip, the influence of column end can be ignored. 2. From the numerical simulation results of the influence factors of lateral constraint, it can be seen that the linear stiffness ratio of Liang Zhu decreases gradually. With the increase of span and the decrease of eccentricity of prestressed tendons, the value of lateral constraint loss of frame beam increases gradually, but the influence of prestress on lateral constraint loss is very small. At the same time, the tensioning construction scheme of prestressed tendons also has a certain influence on the lateral constraint loss. 3. Through the finite element analysis, it is proposed to reduce the span number of frame structure by increasing Liang Zhu's linear stiffness ratio. Reasonable selection of prestressing tendons construction tension sequence and construction measures to reduce the loss of lateral constraints of statically indeterminate structure.
【学位授予单位】：哈尔滨工程大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU378

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