【摘要】：馬鞍山長(zhǎng)江公路大橋右漢斜拉橋?yàn)閲?guó)內(nèi)三個(gè)主塔首次同時(shí)采用的拱形混凝土橋塔的斜拉橋,此種橋型采用塔梁同步的施工方案在國(guó)內(nèi)尚屬首次,現(xiàn)階段并沒(méi)有相關(guān)的資料可供參考,同時(shí)此橋的主梁為寬度達(dá)到了35.3m寬的雙邊箱梁,國(guó)內(nèi)針對(duì)此類(lèi)橋梁的剪力滯效應(yīng)及施工控制方面的研究較少,本文以其為工程背景,主要研究?jī)?nèi)容和成果如下：(1)利用MIDAS軟件建立了橋塔施工的空間有限元模型,分析了主塔的受力和變形情況,通過(guò)計(jì)算及實(shí)測(cè)結(jié)果可知,塔梁同步施工與非塔梁同步施工方案相比,施工過(guò)程中橋塔橫橋向外側(cè)最大拉應(yīng)力及橋塔橫橋向位移有所增大,但幅度有限,橋塔橫橋向最大拉應(yīng)力在安全范圍內(nèi),塔梁同步施工方案對(duì)結(jié)構(gòu)雖有一定的不利影響,但可行。在塔梁同步施工過(guò)程中,通過(guò)參數(shù)分析,確定塔梁同步施工過(guò)程中的主動(dòng)水平力施加位置和大小,改善了橋塔受力。(2)采用ANSYS軟件建立了主梁局部模型,通過(guò)參數(shù)分析可知,雙邊箱主梁頂板厚度增加5cm會(huì)使頂板平均壓應(yīng)力減少,底板平均壓應(yīng)力增大,頂板厚度減少5cm對(duì)主梁頂板和底板的平均應(yīng)力影響較小。頂板厚度減少5cm將使頂板由正剪力滯效應(yīng)轉(zhuǎn)變?yōu)樨?fù)剪力滯效應(yīng)。主梁豎腹板厚度增加或減少5cm對(duì)主梁頂、底板剪力滯效應(yīng)影響有限。設(shè)置橫隔板將使主梁正應(yīng)力分布更均勻,降低剪力滯系數(shù)峰值。(3)主梁懸臂施工過(guò)程中,已經(jīng)張拉完成的斜拉索索力同其后7個(gè)梁段施工關(guān)系密切,之后節(jié)段的施工對(duì)其影響較小。實(shí)測(cè)的索力比理論索力略大一些,這同實(shí)際施工過(guò)程中的臨時(shí)荷載過(guò)多,超重有關(guān)。(4)主梁懸臂施工過(guò)程中現(xiàn)場(chǎng)分析主梁標(biāo)高及索力產(chǎn)生誤差的原因并修正計(jì)算模型,同時(shí)將同主梁標(biāo)高相關(guān)的信息作為輸入樣本,將施工完的標(biāo)高誤差作為輸出數(shù)據(jù),并采用MATLAB神經(jīng)網(wǎng)絡(luò)工具箱實(shí)現(xiàn)改進(jìn)型的BP神經(jīng)網(wǎng)絡(luò),將輸入數(shù)據(jù)同數(shù)據(jù)之間進(jìn)行訓(xùn)練,建立聯(lián)系,得到一個(gè)相關(guān)的模型進(jìn)行線(xiàn)形預(yù)測(cè)分析,通過(guò)與實(shí)測(cè)數(shù)據(jù)進(jìn)行對(duì)比分析,驗(yàn)證了其正確性,并將預(yù)測(cè)結(jié)果反饋到了主梁立模標(biāo)高上,最終實(shí)現(xiàn)了全橋順利合攏且主梁線(xiàn)形流暢,斜拉索、主梁和橋塔受力合理,橋塔偏位正常,橋體結(jié)構(gòu)安全可靠。
[Abstract]:The right Han Cable-Stayed Bridge of Ma'anshan Changjiang River Highway Bridge is the first cable-stayed bridge of arch concrete tower adopted simultaneously by three main towers in our country. At the present stage, there is no relevant data for reference. Meanwhile, the main girder of this bridge is a bilateral box girder with a width of 35.3m wide. There are few researches on the shear lag effect and construction control of this kind of bridge in China. This paper takes it as the engineering background. The main research contents and results are as follows: (1) the spatial finite element model of bridge tower construction is established by using MIDAS software, and the stress and deformation of the main tower are analyzed. Compared with the non-tower beam synchronous construction scheme, the maximum tensile stress and the lateral displacement of the tower transverse bridge are increased in the construction process, but the amplitude is limited, and the maximum tensile stress of the tower transverse bridge is in the safe range. The synchronous construction scheme of tower and beam has some adverse effects on the structure, but it is feasible. In the process of tower beam synchronous construction, the position and magnitude of active horizontal force applied in the process of tower beam synchronous construction are determined through parameter analysis. (2) the local model of main beam is established by using ANSYS software, and the parameter analysis shows that, The average compressive stress of the roof and the average compressive stress of the bottom plate increase with the increase of the thickness of the roof of the two-sided box main girder, and the decrease of the thickness of the roof 5cm has little effect on the average stress of the roof and the floor of the main beam. The thickness of the roof will change from the positive shear lag effect to the negative shear lag effect when the thickness of the roof is reduced by 5cm. The increase or decrease of the thickness of the vertical web of the main beam has a limited effect on the shear lag effect of the top and bottom of the main beam. The installation of the transverse diaphragm will make the normal stress distribution of the main beam more uniform and reduce the peak value of the shear lag coefficient. (3) during the construction of the cantilever of the main beam, the cable force that has already been tensioned is closely related to the construction of the following seven sections of beams. The construction of the subsequent segment has little effect on it. The measured cable force is slightly larger than the theoretical cable force, which is related to the excessive temporary load and overweight in the actual construction process. (4) the causes of the errors in the elevation and cable force of the main girder are analyzed on the spot during the construction of the cantilever of the main beam and the calculation model is revised. At the same time, the information related to the elevation of the main beam is taken as the input sample, the elevation error of the finished construction is taken as the output data, and the improved BP neural network is realized by using the MATLAB neural network toolbox, and the input data is trained between the input data and the data. A relative model is obtained for linear prediction and analysis. The correctness of the model is verified by comparing it with the measured data, and the prediction results are fed back to the elevation of the main beam. Finally, the bridge is closed smoothly, the main beam is linear smooth, the stay cable, the main beam and the bridge tower force is reasonable, the bridge tower is in normal position, and the bridge structure is safe and reliable.
【學(xué)位授予單位】：長(zhǎng)沙理工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類(lèi)號(hào)】：U445.4;U448.27
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本文編號(hào)：2158348