【摘要】：邊中跨比的選取是否合理，不僅會影響到恒載內(nèi)力分布的合理性，，影響到預(yù)應(yīng)力設(shè)計(jì)的合理性和經(jīng)濟(jì)性，影響到施工難易等，而且還會對橋梁的總造價產(chǎn)生很大的影響，因此選擇合理的邊中跨比是連續(xù)剛構(gòu)橋總體設(shè)計(jì)時應(yīng)重點(diǎn)考慮的內(nèi)容。 由于邊中跨比的大小會影響預(yù)應(yīng)力的布置，繼而影響結(jié)構(gòu)內(nèi)力的分布和徐變量的大小，而徐變又會影響結(jié)構(gòu)內(nèi)力重分布，并對跨中下?lián)虾烷_裂產(chǎn)生重要影響。因此，在研究合理邊中跨比時，必須考慮徐變的影響。在目前不能精確分析計(jì)算徐變的情況下，將徐變當(dāng)作一個隨機(jī)變量進(jìn)行包絡(luò)設(shè)計(jì)，估算其對橋梁的影響。并以海心沙大橋及鳧洲大橋?yàn)楣こ瘫尘�，采用徐變包絡(luò)設(shè)計(jì)的方法來分析與研究大跨度三跨和四跨連續(xù)剛構(gòu)橋的合理邊中跨比，通過分析與研究得出使結(jié)構(gòu)受力最優(yōu)且能減少徐變對結(jié)構(gòu)不利影響的合理邊中跨比。 本文的主要工作包括： ⑴閱讀、總結(jié)了近年來國內(nèi)外混凝土連續(xù)剛構(gòu)橋梁合理邊中跨比以及徐變的相關(guān)文獻(xiàn)，闡述了考慮徐變的合理邊中跨比的研究現(xiàn)狀，指出了目前研究中存在的局限性。并與課題組共同提出了將徐變當(dāng)作一個隨機(jī)變量進(jìn)行包絡(luò)設(shè)計(jì)的方法。 ⑵提出了連續(xù)剛構(gòu)橋合理的內(nèi)力目標(biāo)狀態(tài)，著重論述了合理邊中跨比的目標(biāo)是使得連續(xù)剛構(gòu)橋具有合理的內(nèi)力，施工簡單、經(jīng)濟(jì)合理，并采用彎曲能量最小法對現(xiàn)澆三跨和四跨等截面連續(xù)梁的合理邊中跨比進(jìn)行研究。 ⑶介紹了混凝土徐變的機(jī)理、計(jì)算理論及預(yù)測模型，并論述了預(yù)測模型的差異性，并闡述了其對連續(xù)剛構(gòu)橋的影響。 ⑷以海心沙大橋?yàn)楣こ瘫尘�，研究了考慮徐變的三跨混凝土連續(xù)剛構(gòu)橋的合理邊中跨比。 ⑸以鳧洲大橋?yàn)楣こ瘫尘�，研究了考慮徐變的四跨混凝土連續(xù)剛構(gòu)橋的合理邊中跨比。 本文研究取得的主要結(jié)論有： ⑴只有在合理的邊中跨比下，結(jié)構(gòu)的恒載分配才會合理，預(yù)應(yīng)力束布設(shè)相對容易，同時使得徐變對結(jié)構(gòu)的影響最小。 ⑵現(xiàn)澆的三跨等截面連續(xù)梁的合理邊中跨比為0.79，現(xiàn)澆的四跨等截面連續(xù)的合理邊中跨比為0.81。 ⑶以海心沙特大橋?yàn)楣こ瘫尘昂脱芯繉ο�，得到了考慮徐變的三跨混凝土連續(xù)剛構(gòu)橋的合理邊中跨比值的區(qū)間為0.552～0.576。 ⑷以鳧洲大橋?yàn)楣こ瘫尘昂脱芯繉ο�，得到了考慮徐變四跨混凝土連續(xù)剛構(gòu)橋的合理邊中跨比值的區(qū)間為0.577～0.6。
[Abstract]:Whether the ratio of side to middle span is reasonable or not will not only affect the rationality of the distribution of internal forces under dead load, the rationality and economy of prestressed design, and the difficulty of construction, but also have a great impact on the total cost of the bridge. Therefore, it is important to choose a reasonable ratio of side to middle span in the overall design of continuous rigid frame bridge. Because the ratio of side to middle span will affect the arrangement of prestress, and then influence the distribution of internal force and the size of creep variable, creep will affect the redistribution of internal force of the structure, and it will have an important effect on the deflection and cracking in the span. Therefore, the effect of creep must be considered when studying the reasonable ratio of middle to middle span. Under the condition that the creep can not be accurately analyzed and calculated at present, the envelope design is carried out with the creep as a random variable to estimate the influence of the creep on the bridge. Taking Haixinsha Bridge and Fuzhou Bridge as engineering background, the paper analyzes and studies the reasonable ratio of middle to middle span of long-span three-span and four-span continuous rigid frame bridge by using creep envelope design method. Through the analysis and research, it is concluded that the optimum stress of the structure can reduce the adverse effect of creep on the structure, and the reasonable mid-span ratio can be obtained. The main work of this paper is as follows: 1 Reading, summarizing the relevant literature on the reasonable mid-span ratio and creep of concrete continuous rigid frame bridges at home and abroad in recent years, and expounding the research status of the reasonable mid-span ratio of concrete continuous rigid frame bridges considering creep. The limitations of current research are pointed out. A method of envelope design is proposed by using creep as a random variable. 2. The reasonable target state of internal force of continuous rigid frame bridge is put forward, and the objective of reasonable ratio of side to middle span is discussed emphatically, which makes continuous rigid frame bridge have reasonable internal force, simple construction and reasonable economy. The reasonable mid-span ratio of cast-in-place three-span and four-span continuous beams with equal cross-section is studied by means of bending energy minimization method. 3. The mechanism, calculation theory and prediction model of concrete creep are introduced, the difference of prediction model is discussed, and its influence on continuous rigid frame bridge is expounded. 4 taking Haixinsha Bridge as the engineering background, the reasonable mid-span ratio of three span concrete continuous rigid frame bridge considering creep is studied. 5 taking the Fuzhou Bridge as the engineering background, the reasonable mid-span ratio of four span concrete continuous rigid frame bridge considering creep is studied. The main conclusions obtained in this paper are as follows: 1 the distribution of dead load of the structure is reasonable only under the reasonable ratio of side to middle span, and the placement of prestressing tendons is relatively easy, and at the same time, the influence of creep on the structure is minimized. 2 the reasonable ratio of middle to middle span of three-span continuous beam with equal cross-section is 0.79, and that of four-span continuous beam of cast-in-place is 0.81. (3) taking the Haixin Saudi Bridge as the engineering background and the research object, the reasonable mid-span ratio of the three-span concrete continuous rigid frame bridge considering creep is obtained, which is 0.552n0.576. 4 taking the Fuzhou Bridge as the engineering background and the research object, the reasonable mid-span ratio of side to middle span of the concrete continuous rigid frame bridge with four spans considering creep is obtained, which is 0.5770.6.
【學(xué)位授予單位】：華南理工大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：U448.23;U442.5

【參考文獻(xiàn)】

相關(guān)期刊論文 前4條

1 鄧文中;代彤;;重慶石板坡長江大橋復(fù)線橋總體設(shè)計(jì)[J];橋梁建設(shè);2006年06期

2 朱伯芳;混凝土結(jié)構(gòu)徐變應(yīng)力分析的隱式解法[J];水利學(xué)報(bào);1983年05期

3 陳萬里;;鳧洲大橋主橋連續(xù)剛構(gòu)橋設(shè)計(jì)[J];中國科技信息;2006年11期

4 李堅(jiān);我國預(yù)應(yīng)力混凝土連續(xù)梁橋的發(fā)展與工程實(shí)踐[J];中國市政工程;1999年04期

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