【作者】 万其柏；

【导师】 张哲；

【作者基本信息】 大连理工大学 ， 桥梁与隧道工程， 2010， 博士

【摘要】 以斜拉桥为协作主体形成的斜拉桥与其他桥型的协作体系桥梁,具有多样美观的造型、优良的力学性能、良好的使用功能和经济性能等,在现代桥梁工程中得到广泛采用。其形式可分为分载协作和共载协作。其中斜拉-刚构协作体系桥是一种高效的协作体系桥梁,广州的金马大桥就采用这种协作体系桥梁的分载协作形式,形成了目前世界上跨度最大的混凝土独塔结构,获得了显著的经济效益,而桥梁的良好运营以及桥梁体系中蕴含的高效力学性能也促进了对该体系的深入研究。本文即从下述几个方面研究斜拉-刚构协作体系桥的静力特性。通过区分恒载作用下协作体系各部分所承当荷载的位置差异,将协作体系分为分载协作和共载协作两种基本形式,并从力学特性方面考察体系差异,说明这种分类具有一定的合理性。对斜拉-刚构协作体系进行了等效简化,运用弹性地基梁法考察了体系的力学特性。将斜拉索支承的主梁主跨等效为弹性地基梁,按两种模型对结构进行了简化,一种模型将刚构等效为弹性约束,作用于拉索支承的主梁上；另一种将无索区包括进来,将无索区靠近边跨端的约束等效为弹簧约束,按能量法建立平衡方程,并用有限元计算上述两种模型,分析了体系的静力特性。最后参照等征长度的概念,给出了斜拉索支承结构同多跨连续结构的简单类比,由此探讨了无索区的合理取值范围。对于对称形式的分载协作体系桥,以金马大桥为典型桥例,考察了结构主要参数对斜拉-刚构协作体系桥静力特性的影响规律,证实了刚度较大的刚构对于密索斜拉结构的受力特性有较大改善作用；并对体系主要参数选取多个水平,利用均匀设计法安排了数值试验,采用统计回归分析结构特性。对不对称分载协作形式的斜拉-刚构桥,同对称布置形式作对比,指出了结构不对称所带来的优缺点。分别研究了分载协作中结构比例,共载协作中相对刚度对结构力学特性的重大影响,讨论了分载协作体系的连接部位设计和斜拉-刚构协作体系桥的应用。更多还原

【Abstract】 At present, cooperative system bridges of cable-stayed bridges are greatly appreciated for excellent mechanical characteristics and performances, high adaptabilities, low costs and aesthetic appearances, many bridges of this type have been constructed or are being in construction now. Cooperative system bridges have two basic types, different-load cooperation and same-load cooperation. Cooperative cable-stayed and rigid frame system is a high efficient bridge system. The different-load cooperation type of this unique system was adopted in the application of Jimma Bridge in Guangdong, China, which ranked it the longest concrete bridge structure of sigle tower for having two spans of each 283m long. The successful construction of Jimma Bridge with extreme low costs compared to other variations, along with the high efficient inner structural characteristics and satifying performance in service, has greatly prompted the professional study of this system. The doctoral paper is focused on the examination on how the system perfomence so excellently with the cooperation of two structures, moreover, the static mechanical charatersistics of this system under all kinds of important actions are thoroughly discussed. The main research involves the following:Cosidering the difference in the location of the (dead) loads impacted on the structures, there are two basic types of cooperation system, which may simply identify the inner difference of mechanical performance, and reasearch on two systems has indirectly proved this classification is reasonable.The simplifing of cooperative cable-stayed and rigid frame bridge is proposed by suggesting a simulating structure approxmately has equal stiffeness, and the method of beam on elastic foundation is applied to investigate the mechanical performances.Two models both suggesting cable-stayed beams as beams on elastic foundation are studied with the energy principle approach, the first model takes the rigid frame structure as the restraints of cable-stayed structure while the second model calculate the main beam along with the associated rigid frame.Then the two models are throughly analized by FEM to obtain the mechanical performances. By introducing the index length-a defined length of cable-stayed bridge or cooperation system bridges invoving a cable-stayed main structure, then the bridge structure stayed by cables might be simplified as a multi-span continous beam bridge, in which the no cable-stayed zones (or unsupported beams) are considered as the middle or side spans by considering the connections. From the comparision the reasonable variables of no cable-stayed zones might be suggested.As for single tower symmetrical bridges of cooperation system of Jimma type, the characteristics of displacements and inner forces affected by the variables of cooperative cable-stayed and rigid frame bridge are examined, the results show that the rigid frame could improve the performances of slender cable-stayed structure enormously; the experiment design method is used in mathmatical experiments to select and decrease the models to applicable amount from the whole combination of all factors and all major parameters. The interaction of parameters is studied by the stastistics regression process, as several charateristcs then may be attained as how the effects caused by the interaction of the stiffness of beam, tower and cables. Relative high efficient structures may then be determinated by introducing the uniform design method and statistics process.The parametric analysis of the asymmetrical cooperation cable-stayed and rigid frame system is thoroughly carried out along with the comparision between the asymmetrical and symmetrical structure. The above structures of two types are considerably different and the asymmetrical arrangement introduces many advantages as well as certain shortcomings.Study proved that the span ratio is the critical factor in different-load cooperation systems as well as the relative stiffness in same-load cooperation systems. The connection parts are of global great importance in the combination of structures in different-load cooperation system and the reasearch has laid emphasis on the design and calculation of them. Several applications are given and discussed at the end of the paper to expand the range and to demonstrate the efficient of adpotion of cooperation system bridges.更多还原