本文選題：既有橋梁　切入點：車輛荷載效應評估　出處：《福州大學》2014年碩士論文

【摘要】：車輛荷載是橋梁結構最重要的一類設計荷載。隨著車輛超限超載現(xiàn)象日趨嚴峻,既有橋粱的安全性面臨著巨大考驗。本文以多跨混凝土連續(xù)梁橋——福州市鰲峰大橋為工程背景,為了能夠完善地評估該橋的車輛荷載效應,保障橋梁結構的安全使用性能,科學合理地制定養(yǎng)護、加固等決策,本文進行了以下主要工作：(1)根據(jù)環(huán)境振動試驗,以基于頻率的單目標函數(shù)進行有限元模型修正,建立后續(xù)評估所需的基準有限元模型。(2)根據(jù)現(xiàn)有的交通調(diào)查資料,基于平衡更新隨機過程計算特定車隊通過橋梁的概率,結合車隊總重的概率密度函數(shù)以及車隊影響線面積最大值數(shù)據(jù)點集建立該橋的車輛荷載模型,得出正常運營狀態(tài)與異常運營狀態(tài)不同評估基準期的車輛荷載效應最大值概率分布,并與設計荷載作用下的效應值以及規(guī)范限值進行對比評估。(3)利用IBIS-S監(jiān)測系統(tǒng)進行效應監(jiān)測,將實測效應最大值的擬合概率密度函數(shù)及分布函數(shù)同上述理論概率密度函數(shù)及分布函數(shù)進行比較,驗證車輛荷載模型的有效性。計算不同評估基準期實測效應的最大值分布情況,與設計效應進行比較評估,并與上述理論評估結果進行對比。研究結果表明：(1)基于頻率的單目標函數(shù)可用于橋梁的有限元模型修正,修正后計算頻率與實測頻率能夠得到很好的吻合,動力特性的理論計算成果得到很大的改善。(2)不同評估基準期內(nèi),車輛荷載效應最大值分布服從極值Ⅰ型分布,且效應最大值分布的0.95分位值未超過設計效應以及規(guī)范限值,橋梁在后續(xù)服役期間能滿足正常使用狀態(tài)變形要求。當考慮橋梁損傷與橋梁超載這兩種異常運營狀態(tài)時,在滿足一定的損傷和超載條件下,0.95分位值將會超越設計效應,但始終能滿足規(guī)范要求。(3)現(xiàn)有的監(jiān)測數(shù)據(jù)表明,實測效應最大值分布為正態(tài)分布,且后續(xù)運營期間,能滿足正常使用狀態(tài)變形要求。同時結合理論計算與實測計算的尾部分布對比情況,認為采用平衡更新隨機過程理論來獲取效應尾部分位值有一定的合理性。
[Abstract]:Vehicle load is the most important type of design load for bridge structure. With the phenomenon of vehicle overloading becoming more and more severe, the safety of existing bridge beam is facing a great test. In this paper, the multi-span concrete continuous beam bridge-Fuzhou Aofeng Bridge is taken as the engineering background. In order to evaluate the vehicle load effect of the bridge, ensure the safe use performance of the bridge structure, and make scientific and reasonable maintenance and reinforcement decisions, the following main work is carried out in this paper: 1) according to the environmental vibration test, Based on the single objective function based on frequency, the finite element model is modified, and the benchmark finite element model for subsequent evaluation is established. (2) based on the existing traffic survey data, the probability of a specific motorcade passing through the bridge is calculated based on the stochastic process of equilibrium renewal. The vehicle load model of the bridge is established by combining the probability density function of the total weight of the vehicle fleet and the data set of the maximum area affected by the motorcade. The maximum probability distribution of vehicle load effect in different base periods of normal operation and abnormal operation is obtained, and compared with the effect value under the action of design load and the value of code limit, the IBIS-S monitoring system is used to monitor the effect. The fitting probability density function and distribution function of the measured maximum effect are compared with the theoretical probability density function and distribution function. The validity of the vehicle load model is verified. The maximum distribution of the measured effects in different evaluation reference periods is calculated and compared with the design effect. The results show that the single-objective function based on frequency can be used to modify the finite element model of the bridge, and the calculated frequency is in good agreement with the measured frequency. The theoretical calculation results of dynamic characteristics are greatly improved. (2) in different evaluation reference periods, the maximum distribution of vehicle load effect is distributed from extreme value to type 鈪，

本文編號：1691937