基于精细化分析的箱梁研究

发布时间：2018-03-24 21:35

本文选题：Visual　切入点：LISP　出处：《苏州科技大学》2017年硕士论文

【摘要】：“十二五”经济快速发展,车辆荷载等级不断提高、车辆数量不断增加,“十三五”期间,交通设施安全与规模要求越来越高,致使新建桥梁宽度越来越宽,与此同时,不可避免的桥梁病害数量日益增多。箱梁因具有良好的力学性能,如抗弯、抗扭等,所以被广泛应用于桥梁建设中在国际桥梁建设中,因此箱梁精细化研究分析就显得很有必要。以往桥梁设计计算受限于电算发展限制,多以平面杆系理论进行结构计算,其分析计算结果精度相对于现在的“扁平梁”过于粗糙。在实际工程中,结构采用杆系计算通过规范要求,但结构后期运营中还是不可避免的出现病害,无形之中就偏离了设计人员的目的。为弥补平面杆系计算结果固有缺陷,现以精细化分析的思想,通过采用连续梁精细化建模方法,细致分析其结构空间受力状态,并同时对比平面杆系模型,研究两者差异所在,为以后对箱梁进一步研究分析提供一定的指导意义,并从精细化分析角度针对可能存在的病害给出合理加固方案。本文主要研究成果及结论如下所示:论文总结了国内外箱梁桥在桥梁事业中发展现状及趋势,整理了目前常见典型桥梁病害案例,对国内外研究成果、现状以及目前存在不足之处进行综述。并且,简单介绍了箱梁桥常见的病害症状及其原因。详细地对平面杆系计算模型的计算原理及适用条件、优缺点进行论述,简单介绍了梁格、网格模型计算方法,最后着重总结了有限元模型计算方法的优越性、原理以及注意事项。整理LISP语言语法、发展来源,主要重点运用Visual LISP以三跨连续梁为例编写mct建模程序,实现程序辅助自动化建模,克服了钢束信息输入、节点单元等繁杂问题,为箱梁建模提供快速解决方案。着重以等截面三跨连续梁为例,建立平面杆系模型与FEA精细化模型,分别选取中墩墩顶顶板位置、中跨跨中底板、边跨0~1/4L区域分析其应力状况,通过两种模型分析对比规范主要关注的顶底板“面外正应力”、腹板“面内主应力”指标的不同。从精细化分析角度提出理论上对于顶板及底板“面内主应力”同样需要进行控制验算,若不验算会导致顶底板出现斜裂缝病害。再次,对于平面杆系计算结果与现行“扁平梁”结构实际应力情况误差较大,建议设计过程中不仅需要杆系结构计算,而且最好要空间块体单元同时复核较为稳妥。最后针对各种不同位置出现的病害给出常见加固技术方案。
[Abstract]:With the rapid economic development of the 12th Five-Year Plan, the vehicle load grade is constantly increasing and the number of vehicles is increasing. During the 13th Five-Year Plan period, the requirements for the safety and scale of traffic facilities are becoming more and more high, resulting in the width of new bridges becoming wider and wider, while at the same time, Because of its good mechanical properties, such as bending resistance and torsion resistance, box girder is widely used in bridge construction in international bridge construction. Therefore, it is necessary to study and analyze the box girder in detail. In the past, the design and calculation of bridges was limited by the development of computer calculation, and the structural calculation was mostly carried out by the theory of plane bar system. Compared with the present "flat beam", the accuracy of the analysis and calculation results is too rough. In the actual engineering, the structure adopts the bar system calculation to pass the specification requirements, but in the late operation of the structure, there are inevitable diseases. In order to make up for the inherent defects of the calculation results of the plane bar system, in order to make up for the inherent defects of the calculation results of the plane bar system, the detailed modeling method of continuous beam is adopted to analyze the spatial stress state of the structure in detail. At the same time, compared with the plane bar system model, the difference between the two is studied, which provides some guidance for further research and analysis of box girder in the future. In this paper, the main research results and conclusions are as follows: the paper summarizes the current situation and trend of the development of box girder bridges at home and abroad. In this paper, the common typical bridge disease cases are summarized, and the research results, current situation and shortcomings are summarized. This paper briefly introduces the common disease symptoms and causes of box girder bridge, discusses in detail the calculation principle, applicable conditions, advantages and disadvantages of the plane bar system calculation model, and briefly introduces the calculation methods of the beam lattice and grid model. In the end, the superiority, principle and matters needing attention of the finite element model calculation method are summarized emphatically. The grammar and development source of LISP language are arranged. The main emphasis is to use Visual LISP to compile the mct modeling program by taking three-span continuous beam as an example. Program aided automatic modeling is realized, which overcomes the complicated problems such as input of steel beam information and node element, and provides a fast solution for box girder modeling. Taking the three-span continuous beam with equal cross-section as an example, the plane bar system model and the FEA fine model are established. The position of top plate of middle pier, the middle span of middle span and the bottom plate of middle span are selected respectively, and the stress state of the middle span is analyzed in the area of 0 / 1 / 4L. Through the analysis of two models, the difference of "out-of-plane normal stress" and "in-plane principal stress" of the top and bottom plate, which are mainly concerned by the code, is compared. From the angle of fine analysis, the same "in-plane principal stress" of the roof and the floor is proposed theoretically. The sample needs to be controlled and checked. If the calculation is not checked, the inclined crack will occur on the top and bottom slab. Thirdly, it is suggested that the calculation of the plane bar system should not only require the calculation of the bar structure in the design process, but also that the calculation result of the plane bar system and the actual stress situation of the current "flat beam" structure are quite large. And it is better to check the space block unit at the same time. Finally, the common reinforcement technical scheme is given for various diseases in different positions.
【学位授予单位】：苏州科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U448.213

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