高墩大跨连续刚构桥下部结构抗震性能研究

发布时间：2018-01-18 10:36

本文关键词：高墩大跨连续刚构桥下部结构抗震性能研究　出处：《广东工业大学》2014年硕士论文　论文类型：学位论文

【摘要】：随着桥梁预应力技术以及大跨悬臂施工方法的发展,逐渐衍生出了连续刚构这一桥梁基本体系,连续刚构桥由于自身整体稳定性好、利于结构抗震成为近几年来跨河流、峡谷和跨线首选的桥梁结构之一。特别是自我国西部大开发以来,对高墩大跨连续刚构桥梁的需求量越来越大,应用范围越来越广。随着连续刚构桥跨度与墩高不断地加大、加高,桥梁结构的受力也更为复杂,暴露出的震害问题也越来越多。曾经发生在我国西部的四川汶川地震和青海玉树地震都给我们留下了深刻的教训和启示,迫使我们必须在桥梁抗震设计方面有更高水平的理论研究和切合实际、可行有效的防震措施。连续刚构桥是一种墩梁固结体系,在历次震害中表明单独的梁体破坏很少,落梁情况几乎没有,梁体的破坏均是由于墩柱与基础的破坏所致,因而对高墩大跨连续刚构桥墩身抗震性能研究势在必得。本文在高墩大跨连续刚构桥下部结构抗震性能研究方面主要做了以下工作： (1)根据地壳的构成及板块运动理论,剖析地震发生的成因,明确地震度量的方式及地震动特征的描述方式；掌握几组常见地震波加速度曲线的特征,研究其在反应谱分析和时程分析中的适用条件和输入方法。 (2)分析单桩分别在考虑桩-土效应与不考虑桩-土效应条件下的地震动响应情况。研究群桩中单桩之间的相互作用效应与S/d(桩间距／桩径)之间的关系；分析群桩动力阻抗(水平动力阻抗与竖向动力阻抗)与无量纲激振频率的相关性,以及群桩的动力阻抗与单桩动力阻抗之和的大小关系。 (3)分析空心墩连续刚构桥与实心墩连续刚构桥的结构动力特性,比较两者在地震动作用下的响应情况和内力分布规律,进而选择适当的桥墩截面类型和对桥墩截面参数进行可行性优化。 (4)通过对钢筋混凝土桥墩抗震变形能力的研究,明确塑性铰在反复地震作用下形成的原因和在抗震过程中所发挥的作用；通过总结借鉴前人的研究成果,给出等效塑性铰长度、配置箍筋用量和塑性铰区抗剪强度的计算公式。本文的创新之处在于：①连续刚构桥墩身截面分别采用空心矩形截面与实心矩形截面,将这两种不同墩身截面的桥梁结构进行动力特性分析和地震响应分析,确定墩身的最佳截面类型。另外,根据墩身内力分布规律,对墩身截面尺寸进行优化。②探索性的研究钢筋混凝土桥墩变形能力,分析塑性铰对桥墩抗震特性的影响,给出了在塑性铰区配箍的要求和计算方法。本研究为高墩大跨连续刚构桥墩身抗震设计提供了有效的计算思路和分析方法,其研究成果可为连续刚构桥墩身抗震设计和地震响应分析提供参考。
[Abstract]:With the development of bridge prestressing technology and long-span cantilever construction method, the continuous rigid frame is gradually derived as the bridge basic system. The continuous rigid frame bridge has good overall stability. Aseismic structure has become one of the preferred bridge structures across rivers, canyons and lines in recent years. Especially since the development of western China, the demand for long-span continuous rigid frame bridges with high piers is increasing. With the continuous rigid frame bridge span and pier height increasing, the force of bridge structure is more complex. The Wenchuan earthquake in the west of China and the Yushu earthquake in Qinghai province have left us with profound lessons and enlightenment. It is necessary for us to have a higher level of theoretical research and practical, feasible and effective earthquake prevention measures in seismic design of bridges. Continuous rigid frame bridge is a kind of consolidation system of piers and beams, which shows that the damage of single beam is very few, and the condition of falling beam is almost no. The damage of beam is caused by the damage of pier column and foundation. Therefore, the research potential of seismic behavior of pier body of long-span continuous rigid frame bridge with high piers is obtained. The main work of this paper is to study the seismic behavior of the substructure of continuous rigid frame bridge with high pier and long span. 1) according to the theory of crustal composition and plate movement, the causes of earthquake occurrence are analyzed, and the way of earthquake measurement and the description of seismic characteristics are defined. The characteristics of several common seismic wave acceleration curves are grasped and the applicable conditions and input methods in response spectrum analysis and time history analysis are studied. The seismic response of single pile under the condition of considering pile-soil effect and not considering pile-soil effect respectively is analyzed. The interaction effect of single pile in pile group and S / D (spacing / diameter of pile) are studied. The relationship between; The correlation between the dynamic impedance of pile group (horizontal dynamic impedance and vertical dynamic impedance) and the dimensionless excitation frequency, and the relationship between the dynamic impedance of pile group and the sum of the dynamic impedance of single pile are analyzed. 3) the structural dynamic characteristics of hollow pier continuous rigid frame bridge and solid pier continuous rigid frame bridge are analyzed, and the response and internal force distribution of the two bridges under ground motion are compared. Then the appropriate type of pier section and the feasibility optimization of the parameters of pier section are selected. (4) through the study of seismic deformation capacity of reinforced concrete pier, the causes of plastic hinge forming under repeated earthquake and the function of plastic hinge in seismic process are clarified. By summing up the previous research results, the formulas for calculating the equivalent plastic hinge length, the amount of stirrups and the shear strength in the plastic hinge region are given. The innovation of this paper lies in the use of hollow rectangular section and solid rectangular section respectively in the pier section of the continuous rigid frame bridge of 1: 1. The dynamic characteristics and seismic response of these two kinds of bridge structures with different pier sections are analyzed. In addition, according to the law of internal force distribution of pier body, the section size of pier is optimized by .2 exploratory research on the deformation capacity of reinforced concrete pier. The influence of plastic hinge on seismic behavior of bridge pier is analyzed, and the requirement and calculation method of hoop distribution in plastic hinge region are given. This study provides an effective calculation and analysis method for the seismic design of the pier of a long-span continuous rigid frame bridge with high piers. The research results can be used as a reference for seismic design and seismic response analysis of the pier of a continuous rigid frame bridge.
【学位授予单位】：广东工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U442.55;U448.23

【引证文献】