简支梁桥基础托换抗震加固性能的研究

发布时间：2018-06-14 18:58

本文选题：桩基托换 + CFRP加固　；参考：《兰州交通大学》2017年硕士论文

【摘要】：随着地下空间运输通道的快速发展,桩基托换技术以其独特具有的经济性、安全性以及优良的环保性在下穿建筑物的城市地下工程中得到广泛地应用。近年来,世界已进入多地震活动期,地震活动十分频繁,而桥梁作为重要的生命线工程之一,在抗震救灾过程中起到的作用就不言而喻了,因此,对下穿建筑物的城市地下工程中桩基托换的桥梁进行抗震性能研究具有很大的现实意义,而对其采用相应的抗震加固措施来提高或恢复桥梁结构的抗震性能,就显得十分必要。CFRP(碳纤维布)作为一种新型的高性能材料,由于其良好的性能在众多的结构加固工程中备受人们的青睐。本文以兰州市城关区地铁一号线隧道下穿烂泥沟桥的改建加固工程为研究背景,就几种可行方案比较分析,得出桩基托换方案为最优方案。运用ANSYS软件,对原结构、桩基托换结构以及桩基托换后CFRP(碳纤维布)加固墩柱三种结构进行模态分析。通过对结果的比较发现:结构形式不同,每阶振型在所有振型中的贡献率也不同;桩基托换后结构的振动频率增大,而且CFRP加固托换结构后振动频率进一步增大,即振动周期缩短。根据桥梁地震反应谱理论,得到结构的地震频谱值,对原结构、桩基托换结构以及桩基托换后CFRP(碳纤维布)加固墩柱三种结构进行动力反应谱分析。从而得出桩基托换后结构的应力增大,超出规范允许范围,而CFRP加固后结构的应力值减小,说明CFRP加固法提高了结构的抗拉、抗剪承载力。采用EL-Centro波对原结构、桩基托换结构以及桩基托换后CFRP(碳纤维布)加固墩柱三种结构进行地震动时程分析,得到结构的地震响应。桩基托换后CFRP加固结构的应力值较原结构和桩基托换结构的大,跟说明采用CFRP进行结构的抗震加固是是可行有效的。
[Abstract]:With the rapid development of underground space transportation passage, pile underpinning technology has been widely used in urban underground engineering with its unique economy, safety and excellent environmental protection. In recent years, the world has entered a period of multi-seismicity, seismic activity is very frequent, and bridge, as one of the important lifeline projects, plays a self-evident role in the earthquake relief process, therefore, It is of great practical significance to study the aseismic behavior of bridges with pile foundation underpinning in urban underground engineering, and the corresponding seismic reinforcement measures are adopted to improve or restore the seismic performance of bridge structures. As a new kind of high performance material, CFRP (carbon fiber sheet) is very necessary. Because of its good performance, it is very popular in many structural strengthening projects. In this paper, based on the research background of the reconstruction and reinforcement of the tunnel under the tunnel of No. 1 subway line in Chengguan District, Lanzhou City, the author compares and analyzes several feasible schemes and concludes that the pile foundation underpinning scheme is the best. The modal analysis of the original structure, pile foundation underpinning structure and CFRP (CFRP) reinforced pier column after pile foundation replacement is carried out by using ANSYS software. Through the comparison of the results, it is found that the contribution rate of each vibration mode in all modes is different with different structural forms, and the vibration frequency of the structure increases after the pile foundation is replaced, and the vibration frequency increases further after the CFRP reinforcement of the underpinning structure. That is, the vibration period is shortened. According to the theory of bridge seismic response spectrum, the seismic spectrum value of the structure is obtained. The dynamic response spectrum of the original structure, the pile foundation underpinning structure and the CFRP (carbon fiber sheet) reinforced pier column after the pile foundation replacement is analyzed. It is concluded that the stress of the structure after pile foundation replacement increases beyond the allowable range of the code, while the stress value of the CFRP strengthened structure decreases, which indicates that the CFRP strengthening method improves the tensile and shear bearing capacity of the structure. Using EL-Centro wave to analyze the ground motion time history of the original structure, pile foundation underpinning structure and CFRP (carbon fiber sheet) reinforced pier column after pile foundation replacement, the seismic response of the structure is obtained. The stress value of CFRP strengthened structure after pile foundation replacement is larger than that of original structure and pile foundation underpinning structure.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U442.55;U445.72

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