【作者】 张彦林；

【导师】 亓路宽；

【作者基本信息】 北京工业大学 ， 桥梁与隧道工程， 2007， 硕士

【摘要】 近十几年来,钢-混凝土叠合梁桥在城市桥梁和高速公路立交工程等领域得到了广泛的应用,具有显著的技术经济效益和社会效益。由于连续叠合梁结构上缘负弯矩的出现,混凝土桥面板开裂导致叠合梁刚度降低,有害气体、污水或其它腐蚀性液体会渗透到这些裂缝中,引起砼翼板内的钢筋、焊钉以及钢梁的腐蚀,降低了桥梁结构的耐久性,增大了桥梁结构维修和养护的费用和难度。因此叠合梁桥负弯矩区的裂缝问题是一个非常重要的研究课题。为了完善叠合梁的设计计算内容和反映负弯矩区的受力特点,较精确地确定影响裂缝宽度的主要因素,并将其开裂宽度控制在合理的范围之内,有必要进一步对叠合梁负弯矩区的裂缝宽度问题进行试验研究,推动叠合梁结构在我国的应用和发展。本课题采用理论分析、有限元模拟和试验研究相结合的方法开展研究,得到以下主要结论:(1)通过理论分析,并采用大型通用有限元软件ABAQUS来模拟模型中混凝土翼板裂缝产生和发展的过程,找出影响裂缝宽度的主要因素在理论上是可行的。(2)基于有限元分析的结果和以往研究成果,通过设计参数合理变换,采用因子设计法进行构件设计时,能够以较少的试件数量取得较多的试验结果,在试件设计方法上是有效的。(3)混凝土翼板未开裂之前,叠合梁整体工作性能良好,横截面变形符合平截面假定。开裂荷载约为试件极限承载力的25%左右,当达到此荷载时,跨中截面附近混凝土翼板顶面出现第一条裂缝。(4)受拉主筋的配筋率、数量和构成;焊钉间距和高度;以及混凝土翼板的厚度和宽度是影响负弯矩区裂缝宽度和裂缝间距的主要因素。(5)通过改变钢筋构成,即相同配筋率下,采用直径较小的螺纹钢筋可以有效地控制裂缝的发展和分布。在其它试验参数相同的条件下,适当增加配筋率可较好地控制裂缝的产生和发展。更多还原

【Abstract】 In recent several decade years, steel-concrete composite beam bridge has been popularly applied in City Bridge and freeway interchange engineering, and achieved remarkable technique economy benefit and society benefit. Because of the negative bending appears in the top flange of continuous composite beam, and the concrete slab cracking has induced the stiffness depressed; harmfulness gas and polluted water or other corrosive liquid will infiltrated through those cracks, aroused rusting of the rebar, stud and steel beam, reduced the durability of the bridges and enlarged maintenance the cost and difficulty of bridge. Therefore, the crack is a very important research subject.It’s necessary to carry through more experimental study about the crack problem of the continuous composite beam bridge negative bending region, in order to perfected the design calculating content, reflected the stress characteristic, confirmed the major factors of influencing on crack width more accurately, and controlled the crack width in the reasonable range, promoting the composite beam structure’s applying and developing in our country.Based on the results of theoretical analysis, finite element simulation and experimental research, the following conclusions are drawn:(1) It is feasible in theory through the theoretical analysis, and adopting the finite element software ABAQUS to stimulate the process of cracks generating and developing, and finding out the major factors of influencing on the crack width.(2) It is feasible in the design method based on the results of finite element analysis and forefather research findings, altering the design parameters, adopting factorial design method to design specimen can obtain more experimental results by lesser specimens.(3) Composite beam works all right as a whole body and cross section’s deformation accords with the horizontal section assumption. Crack load is about percent 25 of limit load, the first crack will appeared near the mid-span section when reach this load.(4) The major factors of influencing on crack width and space include of rebar content, rebar amount and composing, stud space and height, concrete flange slab thickness and width.(5) Through altering the rebar composition, namely, adopting the smaller diameter deformed reinforcing bar can effective control the crack’s development and distributing. Properly increasing the rebar content can preferable control the crack generating and developing in the other parameters are same.更多还原