钢阻尼盆式橡胶支座水平向受力行为研究

发布时间：2018-03-18 10:18

本文选题：连续梁桥　切入点：减隔震　出处：《西南交通大学》2017年硕士论文　论文类型：学位论文

【摘要】：桥梁作为生命线工程很重要的一员,它的破坏将直接影响震后救援工作,使得次生灾害加重,所以进行桥梁结构抗震设计是必不可少的。连续梁桥具备结构刚度大、桥面变形小、动力性能好、变形曲线平顺、有利于高速行车等突出特点,在我国中小跨径桥梁中应用极为广泛。连续梁桥的支撑体系通常仅在一个中墩上布置固定支座,其余墩上布置活动支座。这种支座布置方式,会导致固定墩在地震作用时承担主要的纵桥向地震力,不能充分利用墩群的抗震能力。为了解决这个问题,本文提出了钢阻尼盆式橡胶支座这种新型减隔震支座,并对该支座受水平力作用时的力学行为进行了详细的研究。在对提出的钢阻尼盆式橡胶支座的构造和工作原理进行了详细的说明之后,对新型支座构造中主要部件之一的工字钢阻尼器大变形下的力学性能进行了研究。首先推导了工字钢阻尼器力-位移关系中屈服前刚度和屈服力的理论计算公式,其次考虑实际盆式橡胶支座的尺寸,确定了截面高度和阻尼器长度的取值范围,采用统计学方法拟合得到了工字钢阻尼器力-位移关系中屈服后刚度和极限强度的简化计算公式。在此基础上,研究了工字钢阻尼器的滞回曲线,并得到了其恢复力模型。在得到了工字钢阻尼器的力-位移关系的主要力学参数后,对钢阻尼器盆式橡胶支座在单向加载和低周往复加载时的力学行为进行了详细的研究,分别推导了两种加载方式下新型支座的力-位移分段函数,并利用有限元数值模拟,进行了验证。在此基础上,进一步提出了新型支座的恢复力模型。将现代智能优化算法中的模拟退火算法引入到新型支座的参数优化中来,提出了基于模拟退火算法的支座参数优化方法,并就其详细的计算流程进行了说明。算法的目标函数定义为固定墩墩底弯矩减小率、墩底弯矩和减小率以及墩梁最大相对位移减小率三者之和。为了满足不同的优化目标,引入三个权重系数来表征上述三种减小率所占目标函数的权重。最后,利用基于模拟退火算法的支座参数方法对采用了新型支座的某四跨连续梁桥进行了参数优化。计算结果表明,新型支座可以起到减小连续梁桥固定墩受力和墩梁相对位移的作用;采用优化后支座参数,桥梁结构在地震动作用下抗震性能相比于初始新型支座得到了有效提升,验证了新型支座参数优化方法的可行性。通过分析,总结出基于模拟退火算法的支座参数优化方法具有通用性、易操作性和较高计算效率的优点,能够很好地解决钢阻尼盆式橡胶支座参数优化的问题。
[Abstract]:As a very important member of lifeline engineering, the damage of bridge will directly affect the rescue work after the earthquake and aggravate the secondary disaster, so it is necessary to carry out seismic design of bridge structure. The bridge deck has the advantages of small deformation, good dynamic performance, smooth deformation curve, favorable to high-speed driving and so on. It is widely used in medium and small span bridges in China. The support system of continuous beam bridges is usually fixed on only one middle pier. The rest of the piers are arranged with movable supports. This type of support arrangement will lead to the bearing of the main longitudinal bridge seismic force on the fixed piers during the earthquake, and will not make full use of the seismic capacity of the piers. In order to solve this problem, In this paper, a new type of shock isolation support, steel damping basin rubber bearing, is proposed. The mechanical behavior of the bearing subjected to horizontal force is studied in detail. The structure and working principle of the proposed steel damping basin rubber bearing are explained in detail. The mechanical properties of I-steel damper, which is one of the main components of new-type support structure, are studied in this paper. Firstly, the theoretical formulas for calculating the yield stiffness and yield force in the load-displacement relation of I-steel damper are derived. Secondly, considering the size of the actual basin rubber bearing, the range of section height and damper length is determined. A simplified formula for calculating the yield stiffness and ultimate strength of I-beam damper is obtained by using statistical method. The hysteretic curve of I-beam damper is studied on this basis. After obtaining the main mechanical parameters of the load-displacement relationship of I-shaped steel dampers, the mechanical behavior of steel dampers under unidirectional loading and low-cycle reciprocating loading is studied in detail. The piecewise force-displacement functions of the new support under two loading modes are derived, and verified by finite element numerical simulation. Furthermore, the restoring force model of the new support is proposed. The simulated annealing algorithm of modern intelligent optimization algorithm is introduced into the parameter optimization of the new support, and the parameter optimization method based on simulated annealing algorithm is proposed. The objective function of the algorithm is defined as the reduction rate of the bending moment at the bottom of the fixed pier, the reduction rate of the bending moment at the bottom of the pier and the reduction rate of the maximum relative displacement of the pier beam. Three weight coefficients are introduced to represent the weight of the objective function occupied by the above three reduction rates. Finally, The parameters of a four-span continuous beam bridge with a new support are optimized by means of the support parameter method based on simulated annealing algorithm. The new support can reduce the force on the fixed pier and the relative displacement of the pier beam of the continuous beam bridge, and the seismic performance of the bridge structure under ground motion can be effectively improved compared with the initial new support by optimizing the parameters of the bearing. The feasibility of the new support parameter optimization method is verified. Through the analysis, the advantages of the support parameter optimization method based on simulated annealing algorithm are summarized, which are universal, easy to operate and high calculation efficiency. It can solve the problem of parameter optimization of steel damping basin rubber bearing.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U442.55

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