本文關(guān)鍵詞：預(yù)應(yīng)力混凝土連續(xù)梁的施工監(jiān)控與剪力滯效應(yīng)研究　出處：《蘭州交通大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 有限元 剪力滯效應(yīng) 預(yù)應(yīng)力連續(xù)箱梁 施工監(jiān)控

【摘要】：近年來,隨著高速鐵路、公路建設(shè)的快速發(fā)展,寬跨度單幅單箱室梁越來越多的應(yīng)用到預(yù)應(yīng)力連續(xù)梁橋、連續(xù)剛構(gòu)橋建設(shè)中,橋梁跨徑及翼緣寬度的增大剪力滯效應(yīng)越來越明顯,不可忽略。本文以寶蘭客專錦屏牛谷河大橋?yàn)楣こ瘫尘?結(jié)合變高度連續(xù)剛構(gòu)橋懸臂澆注的施工方法,研究在施工過程中各階段在恒載及預(yù)應(yīng)力作用下截面的剪力滯效應(yīng)。在進(jìn)行施工階段分析時(shí),本文運(yùn)用ANSYS和MIDAS軟件模擬懸臂施工全過程,并通過對(duì)該橋施工進(jìn)行監(jiān)控控制,提出一些施工過程控制和連續(xù)梁設(shè)計(jì)的理論和建議。重力恒載作用下寬跨比越大,未施加橫向預(yù)應(yīng)力,剪力滯效應(yīng)更明顯,而腹板厚度變化則對(duì)該效應(yīng)影響不甚明顯。在重力和預(yù)應(yīng)力作用下,懸臂施工階段在其剛澆注時(shí)剪力滯效應(yīng)最大,隨著澆注階段的增加剪力滯效應(yīng)呈現(xiàn)遞減規(guī)律。懸臂施工體系轉(zhuǎn)換過程中,各個(gè)截面應(yīng)力及剪力滯變化比較復(fù)雜,中跨各個(gè)截面處剪力滯效應(yīng)變化最大;墩柱處截面頂板壓應(yīng)力變大,剪力滯效應(yīng)變化微小,頂板中間有負(fù)剪力滯效應(yīng),翼緣板兩邊正剪力滯效應(yīng)明顯;邊跨截面在前三個(gè)過程中應(yīng)力和剪力滯基本無明顯變化,邊跨合攏后壓應(yīng)力值減小,負(fù)剪力滯效應(yīng)增大在施工階段隨著連續(xù)梁橋的結(jié)構(gòu)和荷載狀態(tài)的不斷變化,結(jié)構(gòu)內(nèi)力和變形隨之不斷發(fā)生變化。通過現(xiàn)場(chǎng)實(shí)際監(jiān)控?cái)?shù)據(jù)得知,在連續(xù)梁橋懸臂澆筑施工過程中,其主梁撓度較大,由于設(shè)計(jì)時(shí)所采用參數(shù),與實(shí)際工程中所表現(xiàn)出來的參數(shù)不完全一致,使得實(shí)際結(jié)構(gòu)的每一狀態(tài)未必能達(dá)到設(shè)計(jì)值,根據(jù)施工中結(jié)構(gòu)的實(shí)測(cè)值對(duì)主要設(shè)計(jì)參數(shù)進(jìn)行估計(jì),逐步修正設(shè)計(jì)值,重新給出施工中撓度的理論期望值,消除理論值與實(shí)測(cè)值的不一致的主要部分,采用一定的方法和手段對(duì)結(jié)構(gòu)變形、應(yīng)力加以控制,以確保施工得以安全、準(zhǔn)確實(shí)施。在此有限元分析基礎(chǔ)上,對(duì)箱梁剪力滯效應(yīng)在施工過程中的截面幾何影響因素、預(yù)應(yīng)力因素以及體系變換進(jìn)行了計(jì)算分析,并對(duì)橋梁施工過程中以及設(shè)計(jì)中的相關(guān)問題提出了相關(guān)建議,研究結(jié)果對(duì)箱梁橋設(shè)計(jì)有一定的研究價(jià)值。
[Abstract]:In recent years, with the rapid development of high-speed railway and highway construction, the wide span single box box beam is more and more used in the construction of prestressed continuous beam bridge and continuous rigid frame bridge. The shear lag effect of bridge span and flange width is more and more obvious, which can not be ignored. This paper takes Baolanke special Jinping Niu Gu River Bridge as the engineering background, combined with the construction method of cantilever pouring of variable height continuous rigid frame bridge. The shear lag effect of section under dead load and prestress in each stage of construction is studied. In the analysis of construction stage, ANSYS and MIDAS software are used to simulate the whole process of cantilever construction. Through monitoring and controlling the construction of the bridge, some theories and suggestions of construction process control and continuous beam design are put forward. The wider span ratio is increased under the action of gravity dead load, the shear lag effect is more obvious without applying transverse prestress. Under the action of gravity and prestress, the shear lag effect of cantilever construction stage is the biggest when it is just poured. The shear lag effect decreases with the increase of pouring stage. During the transition of cantilever construction system, the variation of stress and shear lag of each section is more complex, and the shear lag effect at each cross section of middle span is the biggest. At the pier column, the compressive stress of the section roof becomes larger, the shear lag effect changes slightly, the negative shear lag effect exists in the middle of the roof plate, and the positive shear lag effect on both sides of the flange plate is obvious. The stress and shear lag of the side span cross section in the first three processes have no obvious change, the compressive stress value decreases after the side span is closed, and the negative shear lag effect increases with the continuous change of the structure and load state of the continuous beam bridge in the construction stage. The internal force and deformation of the structure change constantly. According to the field monitoring data, the deflection of the main beam is larger during the construction of cantilever of continuous beam bridge, because of the parameters used in the design. Because of the inconsistency with the actual engineering parameters, each state of the actual structure may not reach the design value, and the main design parameters are estimated according to the measured value of the structure in construction. The design value is revised step by step, the theoretical expected value of deflection in construction is given again, the main part of the inconsistency between the theoretical value and the measured value is eliminated, and some methods and means are used to control the deformation and stress of the structure. On the basis of the finite element analysis, the influence factors of section geometry, prestressing force and system transformation of box girder shear lag effect in construction process are calculated and analyzed. Some suggestions are put forward for the bridge construction and design, and the results are valuable to the design of box girder bridge.
【學(xué)位授予單位】：蘭州交通大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：U445.57

【參考文獻(xiàn)】

相關(guān)碩士學(xué)位論文 前1條

1 楊濤;大跨徑連續(xù)梁橋施工控制[D];武漢理工大學(xué);2009年

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本文編號(hào)：1390937