本文選題：橋梁 + 氯離子侵蝕��； 參考：《湖南大學》2015年碩士論文

【摘要】：隨著橋梁結(jié)構(gòu)服役時間的推移,材料的性能會發(fā)生退化,尤其是當結(jié)構(gòu)處于氯離子腐蝕環(huán)境下時,鋼筋和混凝土劣變的程度會更加嚴重。作為橋梁下部結(jié)構(gòu)的墩柱一旦發(fā)生損傷,將影響到整座橋梁的耐久性和安全性,其預定的抗震性能也將會降低,所以有必要對橋墩進行抗震性能分析。本文在“國家自然科學基金(51278183)—基于時變易損性的山區(qū)橋梁合理抗震體系研究”的資助下開展,并結(jié)合一典型多跨連續(xù)梁橋,考慮氯離子腐蝕環(huán)境下的RC橋墩發(fā)生材料退化,圍繞橋墩的抗震性能研究做了以下工作:(1)介紹了橋梁在地震作用下的破壞形式以及面臨的耐久性問題,回顧了氯離子侵蝕研究現(xiàn)狀和橋梁結(jié)構(gòu)易損性分析的進展,闡明研究鋼筋混凝土橋墩抗震性能的必要性。(2)詳細講述了氯離子對鋼筋的侵蝕機理,總結(jié)了氯離子在混凝土中的擴散模型�；贔ick第二定律,分析了影響氯離子擴散模型的重要因素,并參照規(guī)范給出了模型主要參數(shù)的取值。(3)采用Open Sees軟件建立算例橋梁有限元模型,結(jié)合前人研究成果,總結(jié)并選擇合適的材料退化模型,計算鋼筋初始銹蝕時間、銹蝕速率以及鋼筋和混凝土的材料退化時變規(guī)律。(4)選擇三條常用地震波,分別針對氯離子腐蝕環(huán)境下的三種分析工況:僅考慮箍筋銹蝕、僅考慮縱筋銹蝕和同時考慮縱筋箍筋銹蝕,對橋墩進行抗震性能分析,比較各工況下抗震能力和地震響應分析結(jié)果,并考慮材料退化時效性的影響。(5)基于橋梁地震易損性分析原理,選擇合適場地類型的100條地震波,對材料退化前后模型進行非線性時程分析,采用傳統(tǒng)可靠度法,對三種工況下橋墩建立時效易損性曲線,比較分析橋墩易損性結(jié)果。最后總結(jié)了研究的結(jié)論,并指出了研究的不足之處以及以后研究發(fā)展的方向。
[Abstract]:Along with the service time of bridge structure, the performance of material will degrade, especially when the structure is in chloride corrosion environment, the degree of deterioration of steel bar and concrete will be more serious.Once the pier column is damaged, the durability and safety of the bridge will be affected, and its intended seismic performance will be reduced, so it is necessary to analyze the seismic behavior of the pier.This paper is supported by the National Natural Science Foundation of China 51278183- study on the rational Seismic system of Mountain Bridges based on Time-Varying vulnerability. Combined with a typical multi-span continuous beam bridge, the material degradation of RC pier under chloride corrosion environment is considered.In this paper, the following work is done to study the seismic behavior of bridge piers: 1) the failure forms and durability of bridges under earthquake are introduced, and the research status of chloride ion erosion and the development of vulnerability analysis of bridge structures are reviewed.The necessity of studying seismic behavior of reinforced concrete pier is expounded. The corrosion mechanism of chloride ion to steel bar is described in detail, and the diffusion model of chloride ion in concrete is summarized.Based on the second law of Fick, the important factors influencing chloride diffusion model are analyzed, and the value of the main parameters of the model is given according to the specification. The finite element model of bridge is established by using Open Sees software.Three commonly used seismic waves are selected to sum up and select appropriate material degradation models, calculate the initial corrosion time, corrosion rate and time-varying law of material degradation of steel bar and concrete.According to three analysis conditions under chloride ion corrosion environment: only considering stirrups corrosion, considering only longitudinal reinforcement corrosion and considering longitudinal reinforcement stirrups corrosion at the same time, the aseismic performance of bridge piers is analyzed.Comparing the results of seismic capacity and seismic response analysis under different working conditions, and considering the influence of material degradation time efficiency.) based on the principle of bridge seismic vulnerability analysis, 100 seismic waves of suitable site type are selected.The nonlinear time history analysis of the model before and after the material degradation is carried out, and the time-dependent vulnerability curve of the pier under three working conditions is established by using the traditional reliability method, and the results of the bridge pier vulnerability are compared and analyzed.Finally, the conclusion of the research is summarized, and the deficiency of the research and the direction of the future research are pointed out.
【學位授予單位】：湖南大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：U442.55

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相關期刊論文 前10條

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本文編號：1760930