【作者】 黄钟霈；

【导师】 霍凯成；

【作者基本信息】 武汉理工大学 ， 结构工程， 2009， 硕士

【摘要】 随着城市的发展和建设,对桥梁建设的速度提出了更高的要求,出现了各种形式的桥面连续简支梁桥。采用湿接缝设计的先简支后连续桥梁,产生两种结构形式:第一种是桥面连续或桥面板连续,其结构形式仍然是简支梁。第二种是结构连续或用预应力使结构连续,其结构形式是连续梁。虽然减少了桥面伸缩缝的数量,也一定程度的有利于改变支座处的桥面开裂现象。但并不能从根本上解决永久支座处负弯矩而导致的桥面裂缝。采用高强混杂纤维增强混凝土作为接缝材料,利用纤维高性能混凝土高抗弯拉、高韧性、高抗渗与高耐久性等特性,改善湿接缝处的受力性能,预防病害的发生。应用于先简支后连续结构体系,可以改善桥梁耐久性,减少后期维护费用,增加桥梁使用寿命。并可为国内其他地区同类城市桥梁建设提供实践经验和技术保证。本文在分析单一纤维混凝土的优缺点、混杂纤维混凝土已初步显出的优势、尚需进一步探索、解决的问题以及前人研究的基础上,做了以下工作:(1)对先简支后连续桥梁结构体系进行了详细分析。介绍了先简支后连续桥梁的型式、做法,先简支后连续桥梁湿接缝的设计。(2)通过对素混凝土、钢纤维混凝土、钢-聚丙烯混杂纤维混凝土进行立方体抗压强度试验和弯曲韧性试验,联系现有文献的试验资料,对比研究了钢纤维与钢-聚丙烯纤维对混凝土的力学性能不同的影响。讨论了不同种类纤维的掺入对混凝土的抗压强度和增韧性能的提高。发现聚丙烯纤维的加入对混凝土的力学性能的改变不明显,略有提高。(3)对采用高强钢纤维混凝土为湿接缝材料与采用普通混凝土材料两跨连续梁进行有限元分析。通过有限元模拟,认为采用高强钢纤维混凝土作为接缝处材料,可以提高连续梁的韧性,增加构件承载能力。与钢纤维对混凝土的增强增韧试验结果基本相符合。说明采用高强钢纤维混凝土作为湿接缝材料,能够改善湿接缝处的受力性能,改善桥梁耐久性,减少后期维护费用,增加桥梁使用寿命。更多还原

【Abstract】 Along with the urban development and the construction,it asked a higher request to the bridge construction’s speed,and presented many forms of continuous bridge erected as simple-supported beam.After using the wet joint design the continuous bridge erected as simple-supported beam,has caused two kind of structural styles:The first kind is the bridge floor continuously or the floorboard is continual,its structural style was still a simple beam.The second kind is the structure continuously or causes the structure with the pre-stressed to be continual; its structural style is continuous beam.It not only reduced the bridge floor expansion joint quantity,but also changed support’s place bridge floor dehiscence phenomenon in certain extent.But it cannot fundamentally solve the bridge floor crack which is caused by the permanent support place hogging moment.Using the high strength fiber reinforced concrete for the joint material,which is high bending,high tensile, high toughness,high anti-permeability and high durability could improve the stress performance of the wet connecting point,and prevent plant disease’s occurrence. When it applies in the continuous bridge erected as simple-supported beam structure system,may improve the bridge durability,reduces later period the maintenance cost, increases the bridge service life.And it could provide the experience and the technical guarantee for other local similar city bridge construction in domestic.After analyzed the sole fiber concrete’s good and bad points,the combination fiber concretes the superiority which appears initially.It is needed to further explore in the foundation,and solute questions.This article in predecessor’s foundation has done the following work:(1) The continuous bridge erected as simple-supported beam has carried on the multi analysis.Introduce the continuous bridge erected as simple-supported beam bridge’s pattern,makes the law,and the continuous bridge erected as simple-supported beam bridge’s wet joint design.(2) Through the plain concrete,the steel fiber concretes and the steel polypropylene promiscuous fiber concretes carries on the cube compressive strength test and the curving toughness test,relate the existing literature the experimental material,the contrast has studied the steel fiber and the steel - polypropylene fiber to the concretes mechanical properties different influence.Discusses the different fibers blend to the concretes compressive strength and the plasticizing performance enhancement.Discover that the polypropylene fiber joined is not obvious to the concretes mechanical properties’ change.(3) Carries on the finite element analysis to the continuous beam,which uses different material in the wet joint,like high strength steel fiber reinforced concrete (HSFC) and common concrete.By the finite element simulation,using HSFC for wet joint material could enhance continuous beam’s toughness,and increase the component bearing capacity.The conclusion basically same as the result of the steel fiber to reinforce and toughen of concrete experiment.As a result,using HSFC for wet joint material could improve the wet point the stress performance,the bridge durability,reduce later period the maintenance cost and increases the bridge service life.更多还原