【摘要】：隨著經(jīng)濟(jì)技術(shù)的不斷發(fā)展,混凝土箱梁的跨度和噸位越來越大,高性能混凝土開始廣泛運用于橋梁的施工之中,然而由于箱梁截面尺寸的不斷增加,加之高性能混凝土的應(yīng)用,導(dǎo)致混凝土水化熱溫度升高、混凝土收縮加大、應(yīng)力增長大,梁體表面出現(xiàn)裂縫,因此使得混凝土結(jié)構(gòu)的耐久性受到很大影響,并且對結(jié)構(gòu)的質(zhì)量和正常使用產(chǎn)生不利影響。大噸位預(yù)制混凝土箱梁由于水泥水化作用而產(chǎn)生的溫度場是導(dǎo)致混凝土產(chǎn)生裂縫的重要原因,然而國內(nèi)和國外的專家對其產(chǎn)生機理和原因進(jìn)行的專項研究相對較少,對箱梁水化熱溫度場及其效應(yīng)的研究還不夠充分。綜上所述,可知對于大跨度預(yù)制箱梁的水化熱溫度場及其影響因素的分析研究,具有相當(dāng)可觀的經(jīng)濟(jì)價值和社會效益。由于箱梁混凝土溫度場的影響因素及其參數(shù)的復(fù)雜多變,所以本文將結(jié)合實際工程進(jìn)行研究,并給出了控制混凝土水化熱的切實可行的措施,為預(yù)制混凝土箱梁施工服務(wù)。本文以哈大高速鐵路預(yù)應(yīng)力混凝土箱梁的預(yù)制工程為背景,首先詳盡論述箱梁預(yù)制的施工全過程,確保不會因為施工問題而影響箱梁混凝土水化熱溫度場的分布。然后進(jìn)行混凝土溫度場的理論分析,并以此為基礎(chǔ)利用ANSYS有限元分析軟件,基于三維非穩(wěn)態(tài)溫度場理論對跨度32m預(yù)制箱梁水化熱溫度場進(jìn)行有限元模擬,將分析所得數(shù)據(jù)與現(xiàn)場實測數(shù)據(jù)進(jìn)行對比研究,并對影響溫度場分布的因素進(jìn)行研究。研究結(jié)果表明采用數(shù)值分析的方法可以較為真實模擬混凝土水化熱溫度場,根據(jù)分析結(jié)果本文提出了控制溫度裂縫的具體措施,并給出了對混凝土箱梁水化熱溫度場分布具有重要作用的影響因素。全文以實際工程項目為背景,運用有關(guān)溫度場理論知識和ANSYS有限元分析軟件,根據(jù)現(xiàn)場工程實際狀況,得到了可應(yīng)用于工程實踐的預(yù)制箱梁的水化熱溫度場及其效應(yīng)。本文的研究成果對于大型混凝土箱梁預(yù)制過程水化熱的溫度監(jiān)控,預(yù)防產(chǎn)生溫度裂縫都提供了較為可靠的依據(jù),具有一定的理論價值和較高的實用價值。
[Abstract]:With the development of economy and technology, the span and tonnage of concrete box girder become larger and larger. High performance concrete is widely used in bridge construction. However, due to the continuous increase of box girder section size, and the application of high performance concrete, As a result, the hydration heat temperature of concrete increases, the shrinkage of concrete increases, the stress increases greatly, and cracks appear on the surface of the beam body. Therefore, the durability of concrete structure is greatly affected, and the quality and normal use of the structure are adversely affected. The temperature field of large-tonnage precast concrete box girder caused by cement hydration is an important reason for the cracks in concrete. The research on the temperature field of box girder hydration heat and its effect is not enough. To sum up, it is concluded that the analysis and study of hydration heat temperature field and its influencing factors of long span prefabricated box girder have considerable economic and social benefits. Because the influence factors and parameters of box girder concrete temperature field are complex and changeable, this paper will study the concrete hydration heat in combination with the actual engineering, and give some practical measures to control the hydration heat of concrete, which will serve the construction of precast concrete box girder. Based on the prefabricated project of prestressed concrete box girder in Harbin and Dalian high speed railway, the whole construction process of box girder prefabrication is discussed in detail, so as to ensure that the distribution of hydration heat temperature field of box girder concrete will not be affected by the construction problem. Then the theoretical analysis of concrete temperature field is carried out, and based on the ANSYS finite element analysis software, the hydration heat temperature field of 32m prefabricated box girder is simulated by using three-dimensional unsteady temperature field theory. The analysis data are compared with the field measured data, and the factors influencing the temperature field distribution are studied. The results show that the numerical analysis method can be used to simulate the hydration heat temperature field of concrete. According to the analysis results, the concrete measures to control the temperature crack are put forward in this paper. The factors that influence the distribution of hydration temperature field of concrete box girder are given. Based on the actual engineering project, using the theoretical knowledge of temperature field and ANSYS finite element analysis software, according to the actual situation of field engineering, the hydration heat temperature field and its effect of precast box girder which can be used in engineering practice are obtained. The research results in this paper provide a reliable basis for the temperature monitoring of hydration heat and the prevention of temperature cracks during prefabrication of large concrete box girder. It has certain theoretical value and high practical value.
【學(xué)位授予單位】：江蘇科技大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：U445.471;U448.13

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本文編號：2203025