浅基桥梁墩台冲刷的护坦防护型式研究

发布时间：2018-04-23 03:14

本文选题：浅基桥梁 + 墩台冲刷　；参考：《长安大学》2015年硕士论文

【摘要】：洪水冲刷造成桥梁墩台基础埋深不足是世界各国桥梁破坏的一个主要原因。桥梁墩台的冲刷防护工程能否达到预期的防护效果,主要取决于其修建的型式、位置及尺寸。国内外大量的桥梁墩台冲刷防护试验研究结果表明,护坦防护措施可以有效地减小墩台的局部冲刷,但尚无普遍规律可以用来指导护坦防护型式的设计。目前我国仍有不少大中桥梁因基础埋深不足需设置局部防护,因此开展相关研究具有重大的科学意义。本文对桥梁墩台冲刷和防护所涉及的相关概念理论进行了梳理,系统地总结了国内外对墩台周围水流结构、冲刷机理、局部冲刷防护问题的研究结果,运用水工模型试验的方法对护坦防护型式进行了研究。重点分析了当护坦顶面位于一般冲刷线附近时,护坦设计参数对桥梁墩台局部冲刷防护效果的影响,并针对具体工程情况提出了合理的护坦防护型式。通过模型试验分析得出:护坦防护型式设计应综合考虑护坦平面形式、顶面埋深、头部延伸长度、防护宽度、迎水面垂裙倾角等设计参数对护坦防护效果的影响,然后确定最终的护坦防护型式尺寸。试验结果证明在桥梁墩台周围设置护坦作为遏制浅基桥梁墩台局部冲刷的工程防护措施是可行的。最终采用的护坦型式与无防护时的冲刷情况进行对比,发现其防护效果明显,护坦在桥梁墩台前和墩台边侧减冲程度均在50%以上。
[Abstract]:The insufficient buried depth of bridge pier and abutment caused by flood is one of the main causes of bridge destruction in the world. Whether the scour protection works of bridge pier and abutment can achieve the expected protective effect mainly depends on the type, position and size of the bridge pier and abutment. A large number of experimental studies on erosion protection of bridge pier and abutment at home and abroad show that the protective measures can effectively reduce the local scour of pier and abutment, but there is no universal rule to guide the design of protective type of dam. At present, there are still many large and medium bridges in our country need to set up local protection because of the insufficient buried depth of foundation, so it is of great scientific significance to carry out relevant research. In this paper, the related concepts and theories related to erosion and protection of bridge pier and abutment are summarized, and the research results of water flow structure, scour mechanism and local scour protection around pier and abutment are systematically summarized at home and abroad. The hydraulic model test method was used to study the protective form of the protective tank. The influence of the design parameters on the local scour protection effect of bridge pier and abutment is analyzed when the top surface of the dam is located near the general scour line, and a reasonable protection type is put forward according to the concrete engineering conditions. Through the model test and analysis, it is concluded that the design parameters such as the flat form, the depth of the top surface, the extension length of the head, the width of the protection, and the inclination angle of the vertical skirt should be considered comprehensively. Then determine the final protection type size. The test results show that it is feasible to install protective dampers around the pier and abutment of the bridge as an engineering protection measure to restrain the local erosion of the pier and abutment of the shallow foundation bridge. Finally, compared with the scour without protection, it was found that the protective effect of the protection was more than 50% in front of the bridge pier and abutment and the side side of the pier and abutment.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U443.86

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