地震对PC连续刚构桥悬臂新浇筑混凝土影响研究

发布时间：2019-03-26 11:35

【摘要】：我国处于地震多发地带,随着交通建设事业的迅速发展,修建了大量的高速公路,国省干线及其它农村公路,桥梁工程作为公路工程的重要组成部分。地震发生后建筑物遭到破坏,不仅会给人民的生命财产直接带来巨大损失,而且使运输物资的交通工程中断,同时给抗震救灾带来巨大困难。雅安受龙门山北东向构造带和川滇南北向构造带的影响,经历了2008年5月12日汶川8.0级地震及2013年4月20日芦山县龙门7.0级地震的破坏。汉源大树大渡河大桥上部结构为挂篮悬臂浇筑的连续刚构,跨度布置为133m+255m+133m,主梁2号墩5号节段挂篮悬浇混凝土于2008年5月11日18时30分开始,5月12日上午9时全面结束。5月12日14时28分,汶川发生里氏8.0级特大强烈地震,挂篮出现较大幅度颤动,已经浇筑完成部分的混凝土强度尚未达到预期强度,地震震动将在一定程度上会造成混凝土损伤,影响新浇筑的混凝土强度以及其与钢筋之间的握裹力,这一问题直接影响到建成后桥梁的安全运营。本文主要针对地震震动对正在施工的大跨径PC连续刚构桥的施工节段开展研究,探讨地震对新浇筑的桥梁节段的影响规律。分析了该桥所采取的处理措施,并对处理后现浇节段进行的检测评价,并开展了成桥后荷载试验。试验和检测结果表明:地震对新浇筑的PC连续刚构桥梁节段的影响主要表现为对终凝前混凝土的影响较小,对终凝和混凝土固化强度达到设计强度的80%之间的混凝土影响较大,需要对其表面的浮浆和分层部分进行凿除和清理,并对新的交界面进行适当的凿毛处理,用水泥浆涂刷交界面,与后续浇筑的混凝土顺接。采取该施工工艺能保证施工节段混凝土的完整性。运营后,该桥的使用性能良好,各种测试指标能够达到设计预期的要求。
[Abstract]:With the rapid development of traffic construction, a large number of highways, provincial trunk lines and other rural roads have been built in China. Bridge engineering is an important part of highway engineering. The destruction of buildings after the earthquake will not only bring great losses to people's lives and property, but also interrupt the transportation of materials and materials, and at the same time bring great difficulties to earthquake relief. Affected by the Longmenshan NE-trending tectonic belt and Sichuan-Yunnan north-south trending tectonic belt, Yaan experienced the destruction of the Wenchuan M8.0 earthquake on May 12, 2008 and the Longmen M7.0 earthquake in Lushan County on April 20, 2013. The superstructure of Dadu River Bridge in Hanyuan is a continuous rigid frame cast by hanging basket cantilever, and the span is 133m 255m 133m. The suspended concrete of main beam No. 2 pier 5 segment hanging basket begins at 18:30 on May 11, 2008. It ended at 9 a.m. on May 12. At 14:28 on 12 May, a strong earthquake of magnitude 8.0 occurred in Wenchuan, a large tremor occurred in the hanging basket, and the strength of the concrete that has been poured has not yet reached its expected strength. Seismic vibration will cause concrete damage to a certain extent, which will affect the strength of newly poured concrete and the binding force between it and steel bars. This problem will directly affect the safe operation of the bridge after completion. This paper mainly focuses on the study of seismic vibration on the construction segments of long-span PC continuous rigid frame bridge, and discusses the influence of earthquake on the new cast-in-place bridge segments. The treatment measures taken by the bridge are analyzed, and the test and evaluation of the cast-in-place section after the treatment are carried out, and the post-bridge load test is carried out. The results of test and test show that the influence of earthquake on the segment of PC continuous rigid frame bridge is less than that of concrete before final setting. The concrete with final setting and concrete solidifying strength up to 80% of the designed strength needs to be drilled and cleaned up on the floating slurry and delamination part of its surface, and the new interface should be properly drilled. Brush the interface with cement slurry and follow-up concrete. This construction technology can ensure the integrity of construction segment concrete. After operation, the performance of the bridge is good, and all kinds of test indexes can meet the requirements of the design.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U442.55;U445.57

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