【作者】 钟轶峰；

【导师】 殷学纲；

【作者基本信息】 重庆大学 ， 固体力学， 2006， 博士

【摘要】 本文主要研究中（下）承式系杆拱桥结构体系和施工监控方法,以正在施工的复式提篮拱桥科研项目为背景,并为重庆大学基础应用基础研究基金项目（项目编号:717411067）。该桥型特点是内拱外倾、外拱内倾,两两组成组合拱肋,并与内、外吊杆和桥面系组合成空间结构体系。其受力复杂,空间效应明显,设计思路不同于通常的系杆拱桥,对于这类桥梁究竟如何分析计算,其结构受力特点如何,受力是否合理,施工如何保证工程质量,实现设计意图等,是桥梁设计者所关心的,笔者根据其自身特点总结出一套切实可行的设计和施工方法,主要内容如下:1.建立中（下）承式系杆拱桥力学模型与吊杆索力优化计算方法。在传统的拱桥计算方法中,为了将实际的拱桥结构转化为力学模型,多年来沿用了多体系假设、多平面假设、上下部结构假设、铰接与刚性连接假设等分析方法。这种假设对于一般的拱桥分析是足够精确的,但对于复杂的结构,尤其对中（下）承式系杆拱桥显得无能为力。论文根据拱桥自身的结构特点和力学特征,对其进行力学性能研究,采用以拱肋、吊杆和桥面体系为一体的整体精细有限元杆梁力学模型。推导出以索力为设计变量、桥面系弯矩应变能最小为优化目标的吊杆索力优化计算公式,并与其它几种常用优化方法进行比较分析。计算出吊索的调索量,得到吊索系的几何刚度阵[ K cg],在引入吊索系几何刚度阵的情况下进行拱桥的静动力分析,形成一个完整的、具有创新性的中（下）承式系杆拱桥的力学分析的理论与方法。（附表内发表论文对应编号:[3],[4]）2.推导出考虑吊杆系初始几何刚度阵的拱桥动力特性和稳定特征值有限元分析方法。中（下）承式拱桥的断桥与垮塌事故大多与吊杆的健康状态有关,传统设计中主要利用桥面简支梁模型计算吊杆内力[ K ]= [K₀]（ [ K₀]为拱桥整体刚度阵）,忽略桥面连续及弹性支撑对吊杆内力的影响,即按线性迭加理论进行分析,计算结果较为粗糙。为了解该桥型的动力和稳定性能（其横向刚度和稳定较弱）,论文首次利用一阶摄动理论推导出引入吊杆系几何初始刚度阵的拱桥动力特性和稳定特征值有限元计算公式,其中[ K ]= [K₀ ]+[K_cg]( [ K_cg]为吊杆长度调整产生的几何刚度阵)。在组建吊杆初始刚度矩阵时考虑桥面系对吊杆索力的影响,给出不同施工阶段合适的简支梁（一期恒载下）和弹性支承连续梁（二期恒载和活载下）桥面系计算模型,以尽可能真实地反映拱桥的实际受力情况,提高计算精度。根据拱桥前15阶振动周期和振型和稳定模态总结出相关的变化规律。针对不同吊杆损伤和吊杆布置形更多还原

【Abstract】 This paper is concentrated on the double R.C X-arch bridge’s structural system and construction control theory. Its inner arch rib inclines outer and the outer arch rib inclines inner. The combination arch ribs, tie-bars, and cross beams make up of space structure system. Its spacial static force、dynamical analysis and stabilization are very important in bridge compute and analysis. The double R.C X-arch bridge’s design idea is different form other tie-bar arch bridge because its inner force is complex and spacial effect is obvious. It’s necessary to sum up a suit of design methods according to its characteristic. On the background of the scientific research items , a complete analysis theory and calculation method which include optimal of the suspender’s tensile force、the static force、the dynamical characteristic、the stabilization and construction control are built. The main subjects are summarized as follow:1. Set up the tie arch bridge’s mechanics model and the optimize compute method.In traditional arch bridge compute method, the multi-system suppose, multi-plane suppose, up-down structure suppose, bore and rigidity connection suppose are used to translate the actual bridge structure into mechanics model. These supposes are accurate to ordinary arch bridge analysis, but not work with the complicated tie arch bridge. This paper researchs the bridge’s mechanics performance according to structure and mechanics characteristic and sets up integer fine FEM mechanics model which consists of arch rib, suspender, bridge board. The suspender’s tensile force is deduced by the optimize method based on the aim that keep the bridge board’s bend moment minimum and compared with orther optimize methods. The suspender’s length and corresponding geometry stiffness matrix [ K cg]are computed. The bridge’s statical and dynamical force are analysised by induct the geometry stiffness matrix which form a complete and innovate mechanics analysis theory and method of the tie arch bridge. （corresponding paper numbers are [3], [4] in appose table）2. Deduce the dynamical characteristic and stabilization eigenvalue FEM analysis methods considering the suspender’s orginal geometry stiffness matrix.The collapse of tie arch bridge is relate to the suspender’s health. In tradition design, the suspender’s tensile force is computed by the simple-support beam model（ [ K ]= [K₀], [ K₀] is the bridge’s stiffness matrix ） which ignore the effect of更多还原