波形钢腹板PC组合梁抗剪性能分析与试验研究

发布时间：2018-11-20 07:23

【摘要】：波形钢腹板组合箱梁以其自重轻、受力明确、预应力效率高、施工周期短等优势，在国内外得到了广泛的研究和应用。我国对该结构的研究起步较晚，但通过各方的努力，在波形钢腹板组合梁的抗弯、抗剪、抗扭及动力性能等方面取得一系列的科研成果，在我国展现出蓬勃发展的态势。以往对波形钢腹板的抗剪性能研究多集中在剪切屈曲方面，例如剪切屈曲形式、破坏形式、影响因素、剪切屈曲强度计算方法等，对波形钢腹板组合梁截面抗剪性能研究较少，顶底混凝土板、波形钢腹板三者间剪力分担比例需要进一步研究，同时对于偏载作用下波形钢腹板剪应力偏大系数计算方法并没有明确，已有的混凝土腹板箱梁偏载增大系数计算方法是否适用需要进一步的研究。因此，本文以自然科学基金项目“波形钢腹板组合梁长期性能分析与试验研究”为依托，进行了波形钢腹板PC组合梁、波形钢腹板RPC组合梁和普通混凝土腹板箱梁的静力加载试验，结合有限元理论分析，研究对称和偏心加载作用下的波形钢腹板剪应力分布、腹板剪力分担比例及腹板剪应力偏载增大系数，并选取实桥进行相关计算分析和工程验证。研究表明：1）有限元理论分析与试验结果吻合性较好，波形钢腹板剪应力沿腹板高度方向分布较均匀；剪应力沿腹板纵向分布受到弯起预应力筋、腹板厚度、横隔板、顶底板厚度等因素的影响和制约；波形钢腹板相邻直板段和水平段在梁的横截面上剪应力分布存在一定比例关系，近似为波折角的余弦值；不同的顶底板混凝土材料，如C50、RPC，对波形钢腹板剪应力分布影响较小，分布近似相同。 2）通过有限元分析及试验验证，试验梁波形钢腹板剪力分担比例为79%~83%范围内，平均值为82%，与广西隆百路2号高架桥、桃花峪跨大堤桥的计算结果平均值近似81%；波形钢腹板分担了截面较大比例的剪力，波形钢腹板按分担截面全部剪力进行设计，具有一定的安全储备；不同的加载方式（中载、偏载）和不同顶底板材料（普通混凝土、RPC）均对截面腹板剪力分担比例影响较小，但腹板剪力分担比例受到腹板厚度、横隔板、顶底板厚度等因素的影响和制约。 3）波形钢腹板剪应力偏载效应明显。波形钢腹板剪应力偏载增大系数不是固定值，与截面形式、箱梁宽度、结构形式以及纵向位置有关。针对本文研究的试验梁形钢腹板剪应力偏载增大系数为1.26~1.30；针对实体工程，广西隆百路2号桥的波形钢腹板剪应力偏载增大系数为1.21~1.42，桃花峪跨大堤桥为1.30~1.40。
[Abstract]:The composite box girder with corrugated steel webs has been widely studied and applied at home and abroad because of its advantages such as light weight, clear force, high prestress efficiency and short construction period. The research on this structure started late in our country, but through the efforts of all parties, a series of scientific research achievements have been obtained in bending, shearing, torsion and dynamic performance of the composite beam with corrugated steel web, showing a vigorous development trend in our country. In the past, the research on shear behavior of corrugated steel web was mainly focused on shear buckling, such as shear buckling form, failure form, influencing factors, calculation method of shear buckling strength, etc. The ratio of shear stress sharing among the top and bottom concrete slabs and corrugated steel webs needs further study, and there is no clear method for calculating the large shear stress coefficient of corrugated steel webs under eccentric loads. It is necessary to further study whether the existing methods for calculating the increasing coefficient of eccentric load of concrete web box girder are applicable. Therefore, based on the natural science foundation project "Long-Term performance Analysis and Experimental study of Waveform Steel Web Composite Beams", the PC composite beams with corrugated steel webs are carried out in this paper. Static loading tests of RPC composite beams with corrugated steel webs and ordinary concrete web box girders are carried out. The shear stress distribution of corrugated steel webs under symmetrical and eccentric loading is studied in combination with finite element theory. The proportion of web shearing force and the increasing coefficient of web shear stress bias load are obtained, and the actual bridge is selected for relevant calculation and engineering verification. The results show that: 1) the theoretical analysis of finite element method is in good agreement with the experimental results, and the shear stress of the corrugated steel web plate distributes uniformly along the height of the web plate; The longitudinal distribution of shear stress along the web is influenced and restricted by the bending prestressed tendons, the thickness of web plates, the thickness of transverse partitions, the thickness of top and bottom plates, and so on. The shear stress distribution of the adjacent straight and horizontal sections of the corrugated steel web is proportional to that of the corrugated angle on the cross section of the beam, which is approximately the cosine value of the corrugated angle. The shear stress distribution of corrugated steel webs with different top and bottom concrete materials, such as C50 RPCs, is similar. 2) through finite element analysis and test verification, the shear sharing ratio of the corrugated steel web plate of the test beam is within 79% and 83%, the average value is 82. The average value is approximately 81% with the calculation results of the No. 2 viaduct of Longbai Road in Guangxi and the great embankment bridge of Taohuayu; The corrugated steel webs share a large proportion of the shear force, and the corrugated steel web plate is designed according to all the shear forces of the section, which has a certain safety reserve. Different loading modes (medium load, partial load) and different top and bottom material (ordinary concrete, RPC) have little influence on the shear sharing ratio of cross-section web plate, but the shear sharing ratio of web plate is affected by the thickness of web plate and transverse partition board. The influence and restriction of the top and bottom plate thickness and other factors. 3) the shear stress bias effect of corrugated steel web is obvious. The increasing coefficient of shear stress bias load of corrugated steel web is not a fixed value, but is related to the form of section, the width of box girder, the form of structure and the longitudinal position. The increasing coefficient of shear stress deviation of the beam web studied in this paper is 1.26 ~ 1.30; For the solid engineering, the increasing coefficient of shear stress bias of the corrugated steel web of No. 2 Longbai Road Bridge in Guangxi is 1.21 ~ 1.42, while that of the Taohuayu Bridge is 1.30 ~ 1.40.
【学位授予单位】：交通部公路科学研究院
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U441

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