型钢混凝土粘结特性对闸墩工作性能的影响研究

发布时间：2019-02-18 21:32

【摘要】：闸墩是水利枢纽中泄水建筑物的主要组成部分,是承受闸门作用力,保证泄水建筑物正常运行的关键性建筑物之一。随着水利水电事业的发展,泄水建筑物挡水闸门的工作水头不断提高,闸墩承受的作用力不断加大,常规钢筋混凝土闸墩已日益难满足安全有效的运行需求,因此很有必要寻求一种新型闸墩结构,确保闸墩在大推力作用下能可靠运行。根据现有研究表明,型钢混凝土(SRC)结构承载能力高、刚性大,具有良好的延性和耗能性,将其应用于闸墩中能较好的满足大推力情况下闸墩可靠运行的要求。但目前国内外对于型钢混凝土闸墩的研究较少,并且这些研究都避开了型钢混凝土粘结滑移问题,而型钢混凝土结构中型钢与混凝土协同工作的基础就是型钢与混凝土之间的自然粘结,靠这种粘结作用才能够发挥出型钢混凝土结构的优点。为揭示型钢与混凝土间的粘结滑移特性对闸墩工作性能的影响,本文在现有研究成果基础之上,结合拟建工程,在数值分析中引入弹簧单元分析了型钢混凝土粘结特性对闸墩工作性能的影响,进一步完善了型钢混凝土闸墩的研究。本文利用ANSYS有限元软件进行数值模拟分析,分别从型钢与混凝土间的粘结滑移、闸墩的位移、应力及裂缝等方面,分析了型钢混凝土粘结特性对闸墩工作性能的影响,在此基础上进一步探讨了不同保护层厚度和不同型钢埋置长度对型钢混凝土粘结性能和闸墩工作性能的影响。研究分析表明：(1)相对于房屋结构中的型钢混凝土梁和柱,型钢混凝土闸墩的型钢与混凝土发生粘结滑移的时机更早,初始滑移荷载为其极限荷载的50%-65%。(2)随着荷载的增加,沿型钢埋置长度方向,牛腿处的型钢混凝土粘结滑移呈现出类似对数分布的分布趋势,而墩体内的型钢混凝土粘结滑移则呈现出类似指数分布的分布趋势。(3)型钢混凝土的粘结特性对闸墩的整体位移没有太大影响,但对局部位移影响较大。(4)型钢混凝土的粘结性能开始先随保护层厚度和型钢埋置长度的增加而提升,当保护层厚度和型钢埋置长度增加到一定值时,型钢混凝土的粘结性能将不再提升,趋于平稳。(5)型钢混凝土出现粘结滑移前,闸墩工作性能几乎不受型钢保护层厚度和型钢埋置长度的影响；型钢混凝土出现粘结滑移后,保护层厚度、型钢埋置长度对闸墩工作性能的影响较大,并且两者的影响有所差异。(6)保护层厚度对闸墩各阶段的裂缝发展趋势的影响不明显,但是对各裂缝阶段的开裂荷载有着很大影响；型钢埋置长度对闸墩各阶段的开裂荷载无明显影响,但相同荷载下,闸墩裂缝分布范围则随型钢埋置长度的增加而减小。
[Abstract]:The pier is the main component of the drainage structure in the water conservancy project. It is one of the key buildings to bear the force of the gate and ensure the normal operation of the drainage structure. With the development of water conservancy and hydropower industry, the working head of the sluice gate of the drainage structure is increasing, and the acting force of the pier is increasing, so it is increasingly difficult for the conventional reinforced concrete pier to meet the requirements of safe and effective operation. Therefore, it is necessary to seek a new type of pier structure to ensure the reliable operation of the pier under the action of large thrust. According to the existing research, the steel reinforced concrete (SRC) (SRC) structure has high bearing capacity, high rigidity, good ductility and energy dissipation, and its application in the pier can better meet the requirements of reliable operation of the pier under the condition of large thrust. However, there are few researches on SRC pier at home and abroad, and these researches have avoided the problem of SRC bond-slip. The natural bond between SRC and SRC is the foundation of SRC working together, and the advantages of SRC can be brought into play by this kind of bond. In order to reveal the influence of the bond-slip characteristics between steel and concrete on the piers' working performance, this paper combines the existing research results with the proposed project. In the numerical analysis, spring element is introduced to analyze the influence of the bond characteristics of SRC on the working performance of the pier, and the research of SRC pier is further improved. In this paper, ANSYS finite element software is used to simulate and analyze the effect of bond characteristics of steel reinforced concrete on the working performance of pier from the aspects of bond slip between section steel and concrete, displacement of pier, stress and crack, etc. On the basis of this, the effects of different protective layer thickness and different section steel embedding length on the bond performance of steel reinforced concrete and the working performance of pier are discussed. The results show that: (1) compared with the steel reinforced concrete beams and columns in the building structure, the time of bond slip between the steel section and the concrete of the steel reinforced concrete sluice pier is earlier than that of the steel reinforced concrete beam and column in the building structure. The initial slip load is between 50 and 65 of its ultimate load. (2) with the increase of load, along with the length of section steel embedded, the bond-slip of steel reinforced concrete at the corbel shows a similar logarithmic distribution trend. The bond slip of SRC in the pier shows a similar exponential distribution trend. (3) the bond characteristics of SRC have no great effect on the overall displacement of the pier. However, the local displacement is greatly affected. (4) the bond performance of SRC begins to increase with the increase of cover thickness and section steel embedding length, and when the cover thickness and section steel buried length increase to a certain value, The bond behavior of SRC will no longer be improved and tends to be stable. (5) before the SRC appears bond-slip, the working performance of the pier is almost independent of the thickness of the steel cover and the embedded length of the section steel; After bond slip occurs in SRC, the thickness of the protective layer and the embedded length of the section steel have a great influence on the working performance of the pier. And the influence of the two is different. (6) the thickness of protective layer has no obvious influence on the development trend of cracks in each stage of pier, but has a great influence on the cracking load of each stage of crack; The length of section steel buried has no obvious influence on the cracking load of pier at each stage, but the crack distribution range of pier decreases with the length of section steel buried under the same load.
【学位授予单位】：广西大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TV662.2

【参考文献】