【作者】 李文武；

【导师】 张哲；

【作者基本信息】 大连理工大学 ， 桥梁与隧道工程， 2013， 博士

【摘要】 我国西部山区经济欠发达、交通设施不完善,地形多山岭重丘,多数桥梁需跨越‘V’形深谷,施工难度大,基于上述实际情况,从经济、技术和环境等方面综合考虑,上承式钢筋混凝土拱桥较其它桥型具有较明显的优势,因此,对山区跨峡谷钢筋混凝土拱桥施工新工艺进行研究具有现实意义。当钢筋混凝土拱桥施工现场及周边缺少预制场地或预制件运输困难时,负角度竖转施工拱肋较为经济,且具有结构整体性好,施工操作方便,后期维修简便,维护费用少的优点。在此背景下,本文以国内首次采用负角度竖转施工的钢筋混凝土拱桥——珍珠大桥为工程背景,在收集和分析国内外负角度竖转施工的相关建设资料及研究成果的基础上,围绕该课题存在的问题,进行了如下问题的研究工作：(1)提出了基于动态无应力构形有限元,为桥梁施工过程模拟计算提供了一种新思路。提出了基于动态无应力长度的有间隙拉压杆单元,用于模拟有间隙栓接杆系结构的力学行为；提出了基于动态无应力长度的悬索单元和桁架单元,可以方便的模拟拉索的张拉施工。为了提高桥梁施工过程模拟的计算效率并确保计算精度,针对不同的结构力学模型采用不同的求解策略,提出了针对部分非线性计算的基于剩余荷载系数增量理论的迭代求解方法。(2)建立了一套适用于桥梁施工过程计算的动态无应力构形有限元计算程序DUFE,不仅能够解决钢筋混凝土拱桥负角度竖转施工问题,而且也能更为准确和方便的模拟桥梁平转及正角度竖转施工过程,模拟斜拉桥、悬索桥等索桥的吊杆张拉施工过程,以及模拟桥梁支座更换过程等其他类型桥梁施工过程计算问题。通过对有限元程序的经典验证算例计算分析,以及钢筋混凝土拱桥施工过程的实例分析,验证了本文基于动态无应力构形有限元计算程序的准确性、可靠性和实用性。(3)对负角度竖转施工过程的关键技术进行了研究。对采用负角度转体施工的拱肋轴线浇筑线形的确定进行了研究。对牵引阶段转体扣索索力和牵引索索力的确定方法做了研究,采用应力平衡法并引入迭代算法确定索力的调整范围。拱肋转体到位后,对劲性骨架合龙过程及临时拉索的拆除方案进行了优化。以珍珠大桥为例,对钢筋混凝土拱桥负角度竖转施工所需要一些关键构造进行设计,为同类工程的设计提供参考。(4)在收集国内外相关资料和深入分析国内外研究成果的基础上,分析了钢筋混凝土拱桥负角度竖转施工误差的来源和类型,并提出了降低结构参数误差对结构受力影响的方法。为了减小钢筋混凝土拱桥负角度竖转施工过程中的施工控制误差,采用不同的控制方法对依托工程珍珠大桥负角度竖转施工时引起施工误差的参数进了敏感性分析,建立一套适于钢筋混凝土拱桥负角度竖转施工控制体系。(5)采用动态无应力构形有限元对贵州珍珠大桥进行负角度竖转施工进行了分析,并与现场施工监控数据进行了比较。对拱肋位移、临时拉索索力及拱肋关键截面应力的实测结果与理论计算结果之间误差产生的原因做了分析,提出和总结了减小误差的方法,为类似桥梁的施工控制提供参考。更多还原

【Abstract】 For the undeveloped economy, inadequate transport facilities and mountainous terrain in China’s western mountains, most bridges need to across the deep V-shaped ravine which is the direct cause of the construction difficulty. Based on the above circumstances, the reinforced concrete deck arch bridge has obvious advantages compared to the other bridges. Therefore, it has practical significance to study the new construction technology of the reinforced concrete arch bridge that across the canyon in mountains area. When there is no prefabrication site around the construction site of the reinforced concrete arch bridge or it is difficult to transport the prefabricated members, it is economically to construct the arch ring with the negative angle vertical rotating method, which aslo has the unique advantages such as convinient installation, good structural intergrity, less and easy maintenance.It is the first time to apply the negative angle vertical rotation construction technology to the reinforced concrete arch bridge in China. Taking Pearl Bridge as an example, and on the basis of the related information collected and in-depth analysis at home and abroad, this paper conducts the following researchs with regard to the existing problems of this subject.(1) The finite element analysis based on the dynamic unstrained geometry is put forward, which provides a new idea for the simulation of the bridge construction process. The tension and compression link element with gaps based on the dynamic unstressed length is put forward to simulate the mechanical behavior of the bolted structures with gaps, the cable element and truss element based on the dynamic unstressed length are put forward to make it more convinient to simulate the tensioning construction of the cable. In order to improve the computational efficiency of the bridge construction process simulation and to ensure the accuracy of calculation, this paper adopts the different solution strategies for different structural mechanics model and puts forward the iterative method based on the remaining load coefficient increment theory for part of the no-linear caculation.(2) This paper establishes a DUFE programe to apply for calculation of bridge construction. This program not only can solve the caculation problem of the negative angle Vertical Rotating Construction of the reinforced concrete arch bridge, but also can solve the caculation problems of other types of bridge such as the stay-cable bridge, suspension bridge, continous beam bridge as well ascontinous rigid frame bridge. The accuracy, reliability and practicability of the finite element computational program based on the dynamic unstressed length in this paper is verified by analyzing the classic validation example of the finite elment program and the instance example of the reinforced concrete arch bridge construction process.(3) This paper studies the key technology during the negative angle vertical rotation construction process and determination of axis linear. In each negative angle vertical rotation construction stage of the arch rib, taking the arch axis linear as the research object to study the completed bridge arch axis linear, the unstressed arch axis linear, the casting arch axis linear and the templet installation coordinate in sequence with the step-by-step algorithm. Study the method of determining the rotation stayed-bukle cable force and the pulling cable force in the traction stage. Adopt the stress balance method and introduce the iterative algorithm to determine the adjustment range of the cable force. Conduct the optimization calculation for the closure process of the stiff skeleton after the arch rib is rotated in place. The optimal removal scheme of the rotation stayed-bukle cable and the temporary tie bar is proposed after the stiff skeleton is closed. Take the Pearl Bridge as the example to design the key structures that are needed when construct the reinforced concrete arch bridge with the negative angle vertical rotation method, which can provide reference for the similar engineering design.(4) It analyzes the sources and types of errors during the negative angle vertical rotating construction of concrete arch bridge and the ways to reduce errors are also proposed on basis of studying the related information collected and researchs at home and abroad. In order to reduce the control errors in the construction process of the reinforced concrete arch bridge with the negative angle vertical rotation construction method, it adopts different kinds of control method to conduct the sensitive analysis of the construction error parameters that is caused in the negative angle vertical rotaion constructon of the Pearl Bridge, and establishes a set of construction control system for the negative angle vertical rotation construction of the reinforced concrete arch bridge.(5) it analyzes the negative angle vertical rotation construction of Pearl Bridge based on the dynamic unstrained geometry FEA. And coMParison with the actual on-site construction monitoring data is conducted. Besides, it also analyzes the cause of difference between theoretical results and the actual monitoring results as for displacement of the arch, temporary traction cable force and stress of key cross section of arch, in addition, it summarizes the ways to minimize the difference which can be referenced for construction monitoring of similar bridges.更多还原