细部构造对钢筋混凝土箱涵结构的抗震性能影响

发布时间：2018-03-20 12:17

本文选题：钢筋混凝土箱涵　切入点：细部构造　出处：《天津大学》2014年硕士论文　论文类型：学位论文

【摘要】：随着地下空间的开发和地下结构建设规模的不断加大，地下空间结构的抗震设计及其安全性评价的重要性、迫切性越来越明显，其抗震性能研究所涉及的内容也十分广泛。浅埋式地下箱涵结构因其上覆土层较薄，受地震作用较为显著，在结构设计时应该更加注意其抗震性能，加强其抗震研究。为探讨浅埋式钢筋混凝土箱涵的抗震性能和确保在地震时箱涵侧壁钢筋先于顶板屈服，运用Final-v11有限元软件对承受反复荷载作用的两个箱涵缩尺试验体建立钢筋与混凝土的分离式模型，其中混凝土用三维实体单元模拟，而钢筋用杆单元模拟，考虑其粘结滑移，进行数值模拟分析，并与试验对比结构的滞回曲线、耗能能力、破坏位置、钢筋应变等，结果表明：数值模拟结果与试验观测结果相吻合，基本能够表现结构的抗震性能和滞回特性，再现结构的破坏状况和钢筋屈服状况。这说明：在试验模拟时钢筋与混凝土之间的粘结滑移本构关系采用Naganuma模型，能够较好的反应其粘结性能；在数值模拟中采用的材料本构关系是合理的，此种数值模拟方法是正确的。为了分析箱涵结构细部构造对其抗震性能的影响，设计了四个变参数模型，对比计算结果可知：增加腋角水平长度和适当加密顶板配筋均能增强箱涵的耗能能力和抗震性能，并能保证反复荷载作用下侧壁钢筋先于顶板屈服，这对箱涵的抗震设计具有指导意义。最后，通过对实际工程中的浅埋式钢筋混凝土箱涵结构（其腋角部分的竖直长度与腋角部分的水平长度之比为1:3）的二、三维受力性能分析可知：用增加腋角部分的水平长度方法能够提高箱涵结构的抗震性能，实现地震时侧壁先于顶板破坏，，保证侧壁钢筋先于顶板屈服的原则，有利于减轻地震时的次生灾害和方便地震后的补强加固。另外，提取二维结构分析的节点位移后，按照相应位置施加在三维模型上的分析问题的方法，能够模拟三维结构的实际受力状态，对于解决类似的三维结构分析问题有借鉴性。
[Abstract]:With the development of underground space and the increasing scale of underground structure construction, the importance of seismic design and safety evaluation of underground space structure becomes more and more obvious. The research on seismic performance of shallow buried underground box culvert is also very extensive. The shallow buried underground box culvert structure should pay more attention to its seismic performance and strengthen its seismic research because of its thin overlying soil layer and strong earthquake action. In order to investigate the seismic behavior of shallow buried reinforced concrete box culvert and ensure that the lateral reinforcement of box culvert will yield before the roof during earthquake, The separated model of steel bar and concrete was established by using Final-v11 finite element software to test two box culverts subjected to repeated load, in which concrete was simulated by three-dimensional solid element, and bar element was used to simulate steel bar, and its bond-slip was considered. Numerical simulation analysis was carried out, and compared with the experimental results, the hysteretic curve, energy dissipation capacity, failure position, steel bar strain and so on of the structure were compared. The results show that the numerical simulation results are in agreement with the experimental observation results. It can basically express the seismic behavior and hysteretic characteristics of the structure, and reproduce the failure state of the structure and the yield state of the steel bar. This shows that the bond-slip constitutive relationship between the steel bar and the concrete is modeled by Naganuma model in the experimental simulation. The material constitutive relation used in the numerical simulation is reasonable and the numerical simulation method is correct. In order to analyze the influence of the detail structure of box culvert on its seismic performance, four variable parameter models are designed. The results of comparison and calculation show that increasing the horizontal length of axillary angle and properly infilling roof reinforcement can enhance the energy dissipation capacity and seismic performance of box culvert. It can guarantee the yield of the side wall reinforcement before the roof under the repeated load, which is of guiding significance to the seismic design of the box culvert. Finally, the ratio of the vertical length of the axillary corner to the horizontal length of the axillary angle of the shallow buried reinforced concrete box culvert in the actual engineering is 1: 3, and the ratio of the vertical length of the axillary corner to the horizontal length of the axillary corner is 1: 3. The results show that the horizontal length method can improve the seismic performance of the box culvert structure by increasing the horizontal length of the axillary angle part, realize the failure of the lateral wall before the roof in earthquake, and guarantee the principle that the reinforcement of the side wall will yield to the roof before the roof. In addition, after extracting the node displacement of the two-dimensional structure analysis, according to the corresponding position applied to the three-dimensional model analysis method, It can simulate the actual stress state of 3D structure, which can be used for reference to solve similar problems of 3D structural analysis.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U449.82

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