【摘要】：近年來,大跨徑預(yù)應(yīng)力混凝土連續(xù)剛構(gòu)橋普遍出現(xiàn)跨中下?lián)蠂?yán)重且持續(xù)發(fā)展的現(xiàn)象,日益威脅橋梁結(jié)構(gòu)的安全性與行車舒適性。因此,明確結(jié)構(gòu)產(chǎn)生過度下?lián)系膶?shí)質(zhì)成為當(dāng)前此類橋型急需解決的課題。國內(nèi)外相關(guān)研究表明,引發(fā)大跨徑預(yù)應(yīng)力混凝土連續(xù)剛構(gòu)橋跨中長期下?lián)线^大的一個重要原因,是由于混凝土材料自身存在較大的隨機(jī)性,進(jìn)而導(dǎo)致傳統(tǒng)的確定性設(shè)計(jì)方法在計(jì)算成橋后長期變形時與實(shí)際情況有很大的差異。對于此類問題,有必要采用隨機(jī)方法對其進(jìn)行研究。綜上所述,本文通過結(jié)合某公路大跨徑預(yù)應(yīng)力混凝土連續(xù)剛構(gòu)橋工程實(shí)例,在確定性分析的基礎(chǔ)上采用隨機(jī)分析方法,并將影響主梁長期變形的幾類不確定性因素考慮在內(nèi),對大跨徑預(yù)應(yīng)力混凝土連續(xù)剛構(gòu)橋的跨中長期變形進(jìn)行概率層面上的分析預(yù)測工作。本文主要研究內(nèi)容包括：(1)簡單概括大跨徑預(yù)應(yīng)力混凝土連續(xù)剛構(gòu)橋長期下?lián)铣梢虻陌l(fā)展歷程和研究成果,列舉國內(nèi)外主流的混凝土收縮徐變理論模型,結(jié)合收縮徐變的機(jī)理以及收縮徐變的主要影響因素,將響應(yīng)面技術(shù)與Monte Carlo法相結(jié)合并應(yīng)用于結(jié)構(gòu)長期變形的隨機(jī)分析中,為計(jì)算分析工作提供了簡明而高效的分析方法。(2)參閱大跨徑橋梁靜力仿真分析資料,對某公路大跨徑預(yù)應(yīng)力混凝土連續(xù)剛構(gòu)橋進(jìn)行靜力條件下的確定性的分析。通過對實(shí)例橋的施工過程控制仿真分析,研究結(jié)構(gòu)的施工過程的內(nèi)力、撓度和應(yīng)力變化規(guī)律。(3)本文提出一個基于Bayesian理論推導(dǎo)的關(guān)于混凝土結(jié)構(gòu)長期變形的計(jì)算框架,其中涉及到重要抽樣技術(shù)和基于響應(yīng)面的Monte Carlo方法,用于提高計(jì)算的穩(wěn)定性以及效率,經(jīng)數(shù)次逐步計(jì)算后便能達(dá)到有效縮小長期變形預(yù)測不確定性的目的。同時通過采用不同的收縮徐變模型條件下的算例來驗(yàn)證該方法的適用性。
[Abstract]:In recent years, the long-span prestressed concrete continuous rigid frame bridge is a common phenomenon of serious and sustainable development of mid-span deflection, which is increasingly threatening the safety and driving comfort of bridge structure. Therefore, it is urgent to solve this kind of bridge at present by clarifying the essence of excessive deflection. Related studies at home and abroad show that the long span prestressed concrete continuous rigid frame bridge caused a long term deflection is due to the large randomness of the material itself. Therefore, the traditional deterministic design method is very different from the actual situation in the calculation of the long term deformation after the bridge is completed. For this kind of problem, it is necessary to use random method to study it. To sum up, combining with the engineering example of a highway long-span prestressed concrete continuous rigid frame bridge, this paper adopts the stochastic analysis method based on deterministic analysis, and takes into account several kinds of uncertain factors that affect the long-term deformation of the main beam. The long-span prestressed concrete continuous rigid frame bridge is analyzed and forecasted on the probability level. The main research contents of this paper are as follows: (1) the development history and research results of long-time deflection of long-span prestressed concrete continuous rigid frame bridge are summarized, and the theoretical models of shrinkage and creep of concrete are listed. Combined with the mechanism of shrinkage and creep and the main influencing factors of shrinkage and creep, the response surface technique and Monte Carlo method are combined and applied to the random analysis of long-term deformation of structures. It provides a simple and efficient analysis method for the calculation and analysis. (2) referring to the static simulation analysis data of long-span bridge, the deterministic analysis of a highway long-span prestressed concrete continuous rigid frame bridge under static condition is carried out. Through the simulation analysis of the construction process control of the concrete bridge, the internal force, deflection and stress of the structure are studied. (3) this paper presents a calculation framework for the long-term deformation of concrete structure based on the Bayesian theory. The important sampling technique and the Monte Carlo method based on response surface are involved to improve the stability and efficiency of the calculation. After several successive calculations, the uncertainty of long-term deformation prediction can be effectively reduced. At the same time, the applicability of the method is verified by examples under different shrinkage and creep models.
【學(xué)位授予單位】：西南交通大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：U441;U448.23

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本文編號：2314844