本文選題：橋梁　切入點：強健性　出處：《西南交通大學》2015年碩士論文　論文類型：學位論文

【摘要】：現(xiàn)代橋梁結構所處的環(huán)境日益復雜,在運營階段部分構件的損傷與破壞不可完全避免,因此確定橋梁結構各構件的重要性系數(shù),研究在某構件失效時橋梁結構是否具有良好的抗連續(xù)倒塌能力顯得尤為重要。但是目前對于橋梁連續(xù)倒塌的研究相對匱乏。論文從各類橋梁結構入手,將橋梁結構分為四類連續(xù)倒塌模式,并以能量法計算橋梁結構各構件的重要性系數(shù),分析橋梁結構在出現(xiàn)構件失效時的強健性。論文主要的研究工作和結論如下：1.歸納總結建筑結構強健性研究成果的基礎上,指出現(xiàn)行的橋梁規(guī)范在連續(xù)倒塌設計方面研究的不足,而橋梁結構在運營階段遇到的偶然荷載具有很強的不確定性,部分構件的損傷和失效不可避免,因此提出橋梁結構需要研究因特殊事件導致構件失效的情況下橋梁結構的強健性。2.根據(jù)橋梁結構發(fā)生連續(xù)倒塌的狀態(tài)將橋梁結構連續(xù)倒塌分為四類連續(xù)倒塌模式,利用能量法計算橋梁各構件的重要性系數(shù),并結合定性分析對橋梁結構構件分類,確定各倒塌類型橋梁結構中的關鍵構件；利用ANSYS的瞬態(tài)分析功能,以構件瞬時拆除法模擬構件突然失效,分別對多類橋梁構件失效進行靜力、動力分析。3.分析表明,橋梁結構中重要性系數(shù)大的構件失效時對剩余結構的動力影響顯著,某些構件失效會導致橋梁結構在極短的時間內(nèi)發(fā)生連續(xù)性破壞。討論橋梁結構中構件的安全儲備量并確定其合理取值。對于“多米諾型”連續(xù)倒塌橋梁以自錨式懸索橋為算例,分析表明吊索突然斷裂對緊鄰的吊索影響劇烈,為避免單根吊索突然斷裂引起吊索連續(xù)斷裂,吊索安全儲備應超過2.5;為避免相鄰兩根吊索同時斷裂引起吊索連續(xù)斷裂,吊索的安全系數(shù)應調(diào)整為原設計的1.4倍,即將安全系數(shù)取為4.2；對于“失穩(wěn)型”連續(xù)倒塌橋梁以某造型獨特的斜拉橋為算例,分析表明,該橋的圓拱形橋塔處設置的對拉索失效將導致橋梁結構連續(xù)倒塌,為避免這一情況的出現(xiàn),橋塔的剛度應增大到原設計值的1.7倍,使橋梁結構具有良好的強健性；對于“外部約束”連續(xù)失效型橋梁以連續(xù)梁橋為算例,分析表明,梁端處重載側(cè)的豎向約束失效會導致剩余約束連續(xù)失效,為避免這一情況,連續(xù)梁中間墩處應增設抗扭約束。
[Abstract]:The environment of modern bridge structure is becoming more and more complex, and the damage and damage of some components can not be completely avoided in the operation stage. Therefore, the importance coefficient of each component of bridge structure is determined. It is very important to study whether the bridge structure has good ability to resist continuous collapse when a member fails. However, the research on continuous collapse of bridge is relatively scarce. The bridge structure is divided into four types of continuous collapse modes, and the importance coefficient of each component of the bridge structure is calculated by energy method. The main research work and conclusions of this paper are as follows: 1. On the basis of summarizing the research results of building structure robustness, It is pointed out that the existing bridge codes are insufficient in the research of continuous collapse design, and the accidental loads encountered in the operation stage of bridge structures are very uncertain, so the damage and failure of some members are inevitable. Therefore, it is necessary to study the robustness of bridge structure under the condition of structural failure caused by special events. 2. According to the state of continuous collapse of bridge structure, the continuous collapse of bridge structure can be divided into four types of continuous collapse modes. Using the energy method to calculate the importance coefficient of each component of the bridge, and combining qualitative analysis to classify the components of the bridge structure, to determine the key components of each collapse type bridge structure, to use the transient analysis function of ANSYS, In this paper, the transient demolition method is used to simulate the sudden failure of the member, and the static analysis of the failure of many kinds of bridge members is carried out respectively. 3. The analysis shows that the dynamic effect on the residual structure is significant when the member with the large importance coefficient of the bridge structure fails. The failure of some components will lead to the continuous damage of bridge structure in a very short time. The safety reserve of the components in the bridge structure is discussed and the reasonable value is determined. The self-anchored suspension bridge is taken as an example for a "domino" continuous collapse bridge. The analysis shows that the sudden fracture of the sling has a severe effect on the adjacent slings. In order to avoid the continuous fracture of the sling caused by the sudden fracture of the single sling, the safety reserve of the sling should exceed 2.5, and to avoid the continuous fracture of the sling caused by the simultaneous fracture of the adjacent two sling lines, The safety factor of the sling should be adjusted to 1.4 times of the original design, that is to say, the safety factor should be taken as 4.2. For the continuous collapse of the "unstable" bridge, a special cable-stayed bridge of unique shape is taken as an example. The failure of cable at the circular arch tower of the bridge will lead to the continuous collapse of the bridge structure. In order to avoid this situation, the stiffness of the tower should be increased to 1.7 times of the original design value, so that the bridge structure has good robustness. For the continuous failure bridge with "external constraint" as an example, the analysis shows that the vertical constraint failure of the overloaded side at the end of the beam will lead to the continuous failure of the residual constraint. In order to avoid this situation, the torsional constraint should be added at the middle pier of the continuous beam.
【學位授予單位】：西南交通大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：U441

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本文編號：1611451