本文關鍵詞：開裂在役鋼筋混凝土梁加卸載剛度與正常使用可靠度分析　出處：《西南交通大學》2017年碩士論文　論文類型：學位論文

  更多相關文章： 鋼筋混凝土 拉伸剛化 慣性矩 正常使用狀態(tài) 可靠度

【摘要】：鋼筋混凝土構件被廣泛應用于各種工程中,但由于混凝土的抗拉強度較低,在正常服役過程中,鋼筋混凝土結構可能因為各種因素導致開裂,如構件遭受設計外過載或偶然沖擊作用等。在意外荷載卸載后,由于混凝土開裂與鋼筋混凝土粘結損傷的影響,構件剛度會下降,從而導致正常使用變形增大,以及正常使用可靠度降低。本文旨在于提出一種在役開裂鋼筋混凝土梁正常使用可靠度的計算方法,并論證開裂損傷對鋼筋混凝土梁正常使用可靠度的影響。本文報道了 11片鋼筋混凝土梁的反復加卸載試驗。根據(jù)實測的梁體裂縫分布形態(tài)與荷載-位移響應結果,計算了裂后鋼筋混凝土梁重復加載的實測平均慣性矩。利用4片設計參數(shù)一致的鋼筋混凝土梁的試驗結果,驗證了平均慣性矩模型在可靠度分析中的有效性。利用本文的11片梁試驗數(shù)據(jù)和歷史文獻數(shù)據(jù),校核了有效慣性矩模型和平均慣性矩模型的不確定性。本文利用蒙特卡羅法來考慮鋼筋混凝土結構的隨機性,并采用平均慣性矩模型分析了歷史開裂損傷對鋼筋混凝土梁的正常使用可靠度的影響,定量計算了開裂鋼筋混凝土梁的短期和長期正常使用可靠度及其損失。研究結果表明,當歷史荷載產(chǎn)生的變形可能大于變形限值時,需要考慮歷史開裂損傷對短期正常使用可靠度的影響,輕度的歷史損傷雖然會影響構件變形響應的概率密度,但不會影響短期正常使用可靠度。然而,在考慮收縮徐變效應時,歷史開裂損傷會削弱梁體剛度,從而增大徐變和收縮的時變變形,因此即使輕度的歷史損傷也會降低構件的長期正常使用可靠度。另外,鋼筋混凝土梁遭受損傷荷載的時間越晚,開裂損傷對長期正常使用可靠度的影響就越小。
[Abstract]:Reinforced concrete members are widely used in various projects, but due to the low tensile strength of concrete, in the normal service process, reinforced concrete structures may cause cracking due to various factors. For example, members are subjected to design overload or accidental impact. Due to the effect of concrete cracking and bond damage of reinforced concrete, the stiffness of members will decrease after unload of accidental load, which will lead to the increase of normal service deformation. The purpose of this paper is to put forward a method to calculate the reliability of cracking reinforced concrete beams in service. The effect of cracking damage on the reliability of reinforced concrete beams in normal use is also discussed in this paper. Repeated loading and unloading tests of 11 reinforced concrete beams. According to the measured results of crack distribution and load-displacement response of beams. The measured average moment of inertia of a cracked RC beam subjected to repeated loading is calculated. The experimental results of 4 RC beams with the same design parameters are used. The validity of the mean moment of inertia model in reliability analysis is verified. The experimental data of 11 beams and historical literature data are used in this paper. The uncertainty of the effective moment of inertia model and the average moment of inertia model is checked. In this paper, the randomness of reinforced concrete structure is considered by Monte Carlo method. The average moment of inertia model is used to analyze the influence of historical cracking damage on the reliability of reinforced concrete beams. The reliability and loss of short and long term normal use of cracked reinforced concrete beams are calculated quantitatively. The results show that the deformation caused by historical loads may be greater than the deformation limit. It is necessary to consider the impact of historical cracking damage on the reliability of short-term normal use. Although mild historical damage will affect the probability density of deformation response, it will not affect the short-term reliability of normal use. When the shrinkage and creep effect is considered, the historical crack damage will weaken the stiffness of the beam, thus increasing the creep and the time-varying deformation of the shrinkage. Therefore, even mild historical damage will reduce the long-term normal use reliability of the members. In addition, the later the RC beam is subjected to the damage load, the smaller the impact of cracking damage on the long-term normal use reliability.
【學位授予單位】：西南交通大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：TU375.1

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本文編號：1413511