本文選題：應(yīng)力損失 + 有效應(yīng)力��； 參考：《河北工程大學(xué)》2015年碩士論文

【摘要】：預(yù)應(yīng)力混凝土橋梁上部結(jié)構(gòu)中的預(yù)應(yīng)力鋼束的有效應(yīng)力計(jì)算是預(yù)應(yīng)力設(shè)計(jì)中的關(guān)鍵步驟。預(yù)應(yīng)力鋼束的有效應(yīng)力等于鋼束預(yù)應(yīng)力張拉值減去預(yù)應(yīng)力損失。但是在實(shí)際的橋梁工程中,預(yù)應(yīng)力鋼束應(yīng)力損失的影響因素很多,結(jié)構(gòu)的施工過(guò)程和使用過(guò)程中造成計(jì)算誤差的成因也很復(fù)雜,最終難以得到較為精確的有效預(yù)應(yīng)力值。相關(guān)規(guī)范給出了預(yù)應(yīng)力設(shè)計(jì)階段中計(jì)算鋼絞線應(yīng)力損失的幾種情況及對(duì)應(yīng)的計(jì)算公式,按照規(guī)范計(jì)算出的鋼束各項(xiàng)預(yù)應(yīng)力損失與實(shí)測(cè)值基本一致,但仍存在一定誤差。鋼絞線的有效預(yù)應(yīng)力實(shí)際值和計(jì)算值之間的誤差可直接影響到結(jié)構(gòu)的壽命和使用性能,二者差值過(guò)大甚至?xí)䦟?dǎo)致橋梁出現(xiàn)安全事故。因此我們需要更加細(xì)致和全面地掌握預(yù)應(yīng)力鋼束在實(shí)際使用情況下的有效應(yīng)力,以此為依據(jù)來(lái)指導(dǎo)預(yù)應(yīng)力設(shè)計(jì),以此為參考來(lái)了解橋梁的使用性能,并以此為前提條件來(lái)進(jìn)行結(jié)構(gòu)的評(píng)估和檢測(cè)。本研究運(yùn)用有限元理論對(duì)某預(yù)應(yīng)力混凝土曲線橋梁工程實(shí)例進(jìn)行了一系列計(jì)算分析。首先得出該曲線箱梁在自重作用下受力特點(diǎn),后通過(guò)探索曲線箱梁受力狀態(tài)隨曲率半徑的變化規(guī)律和鋼束張拉次序?qū)Y(jié)構(gòu)受力性能分析全面掌握了該箱梁及其預(yù)應(yīng)力鋼束的受力狀態(tài)。最后分別采用傳統(tǒng)有效應(yīng)力計(jì)算理論和有限元分析計(jì)算兩種方法對(duì)比該工程實(shí)例中的預(yù)應(yīng)力鋼束的有效應(yīng)力,兩種計(jì)算結(jié)果數(shù)值接近且規(guī)律相似,進(jìn)一步得到箱梁不同部位預(yù)應(yīng)力鋼束的應(yīng)力損失規(guī)律。計(jì)算結(jié)果肯定了本研究所使用的有限元建模理論的正確性,可對(duì)類似箱梁的相關(guān)研究提供一定參考價(jià)值。
[Abstract]:The calculation of the effective stress of prestressed steel bundle in the superstructure of prestressed concrete bridge is a key step in the design of prestressed concrete bridge. The effective stress of the prestressed steel bundle is equal to the prestressing tensioning value minus the prestress loss. However, in the actual bridge engineering, there are many factors affecting the stress loss of prestressed steel beam, and the causes of the calculation error in the construction process and the use process of the structure are also very complicated, so it is difficult to obtain the more accurate effective prestress value. Several cases and corresponding formulas for calculating the stress loss of steel strands in the stage of prestress design are given in the relevant codes. The calculated prestressing loss of steel strands according to the code is basically consistent with the measured values, but there are still some errors. The error between the actual value of effective prestress and the calculated value of steel strand can directly affect the service life and performance of the structure. The difference between the two values is too large and even leads to the safety accident of the bridge. Therefore, we need to grasp the effective stress of prestressed steel bundle in practical use more meticulously and comprehensively, so as to guide the design of prestressing force, and use it as a reference to understand the performance of the bridge. And take this as the premise condition to carry on the structure appraisal and the inspection. In this paper, the finite element theory is used to calculate and analyze a prestressed concrete curved bridge project. First of all, the stress characteristics of the curved box girder under the action of deadweight are obtained. After that, the stress state of the box girder and its prestressed steel beam are fully grasped by exploring the variation of the stress state of the curved box girder with the curvature radius and the tension sequence of the steel bundle. Finally, the traditional effective stress calculation theory and the finite element analysis method are used to compare the effective stress of the prestressed steel beam in the engineering example. The results of the two methods are close and the law is similar. Furthermore, the stress loss law of prestressed steel bundle in different parts of box girder is obtained. The calculation results confirm the correctness of the finite element modeling theory used in this paper, and can provide some reference value for similar box girder research.
【學(xué)位授予單位】：河北工程大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：U441

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本文編號(hào)：1929162