外加钢筋网水泥砂浆加固砌体结构受力性能分析

发布时间：2019-01-09 01:41

【摘要】：砌体结构因造价比较低廉、容易就地取材、耐火性比较好、良好的保温隔热性能以及施工操作简便等优点,普遍应用于世界各国。但砌体结构尤其是无筋砌体结构的完整性较差,承载力比较低。当砂浆强度低、抗震构造措施欠缺时,抗震性能很差。抵抗地震作用的能力薄弱,震损后是否能够合理利用,进行抗震加固后能否满足现行规范的要求,还有待于研究。在我国房屋建筑中,砖砌体结构仍占有较大的比例,只是砖砌体结构的抗拉、抗弯及抗剪强度均较低,在遭受地震荷载作用时极易造成脆性破坏。采用钢筋网水泥砂浆面层加固砖砌体可以有效提高砖砌体结构的延性和强度。为此,研究钢筋网水泥砂浆加固砖砌体结构的抗震加固问题具有重要的实际意义。本文采用外加钢筋网水泥砂浆加固无筋砖砌体结构,使用有限元软件数值模拟加固前后的砌体房屋,对其受力性能进行研究和分析,获得的结论可供实际工程做理论参考。主要研究工作如下:1.运用有限元方法对无筋砌体结构进行了数值模拟,并从开门一侧和开窗一侧分析无筋砌体墙体受力性能,得到了其在不同荷载作用下位移-力骨架曲线图,此图能反映位移和力的变化关系。根据砌体模型中的Mises应力,从加载方案-位移单调加载、位移周期加载、单调加载和周期加载四种方法分析无筋砌体墙体极限承载力,判断损伤位置、程度以及砌体结构裂缝。2.基于建立的带构造柱-圈梁的砌体结构中一片墙体的有限元模型,在承受水平位移、水平力、位移周期加载和周期加载这四种加载方式下研究带构造柱-圈梁的墙体的受力性能,并分析位移和荷载的关系。研究不同等级的砂浆强度、高宽比和竖向应力对墙体极限承载力的影响。3.建立外加钢筋网水泥砂浆的无筋砖墙体有限元模型,计算并对比墙体加固前后在水平荷载下模型的应力-应变分布规律,分析加固层砂浆厚度、钢筋网间距、砌筑砂浆强度、高宽比及竖向压应力等对砌体结构承载力的影响,并给出相应的建议。
[Abstract]:Masonry structure is widely used all over the world because of its advantages such as low cost, easy to use local materials, good fire resistance, good thermal insulation and easy operation. However, the integrity and bearing capacity of masonry structures, especially unreinforced masonry structures, are poor. When mortar strength is low and seismic structural measures are lacking, seismic performance is very poor. The ability of resisting earthquake action is weak, whether it can be used reasonably after earthquake damage, and whether it can meet the requirements of current code after seismic reinforcement is still to be studied. In our country, the brick masonry structure still occupies a large proportion, but the tensile strength, bending strength and shear strength of the brick masonry structure are all low, which can easily cause brittleness failure when subjected to earthquake load. The ductility and strength of brick masonry structure can be improved effectively by strengthening brick masonry with reinforced concrete mortar. Therefore, it is of great practical significance to study the seismic reinforcement of brick masonry structure strengthened with reinforced concrete mortar. In this paper, the reinforced concrete mortar is used to reinforce the unreinforced brick masonry structure, and the finite element software is used to simulate the masonry building before and after reinforcement. The mechanical behavior of the masonry building is studied and analyzed. The conclusions obtained can be used for theoretical reference in practical engineering. The main research work is as follows: 1. The finite element method is used to simulate the unreinforced masonry structure, and the mechanical behavior of the unreinforced masonry wall is analyzed from the side of the door and the side of the window, and the displacement-force skeleton diagram of the wall is obtained under different loads. This diagram can reflect the relationship between displacement and force. According to the Mises stress in the masonry model, the ultimate bearing capacity of unreinforced masonry wall is analyzed by four methods, namely, displacement monotone loading, displacement cyclic loading, monotone loading and periodic loading, and the damage location is judged. Extent and cracks in masonry structures. 2. Based on the established finite element model of a wall in a masonry structure with a structural column and a ring beam, the wall is subjected to horizontal displacement, horizontal force, Under the four loading modes of displacement periodic loading and periodic loading the mechanical behavior of wall with structural column-ring beam is studied and the relationship between displacement and load is analyzed. The influence of mortar strength, aspect ratio and vertical stress on ultimate bearing capacity of wall is studied. The finite element model of unreinforced brick wall with reinforced concrete mortar was established, and the stress-strain distribution of the model before and after reinforcement was calculated and compared, and the thickness of reinforced mortar, the spacing of reinforcing bar and the strength of masonry mortar were analyzed. The influence of aspect ratio and vertical compressive stress on the bearing capacity of masonry structure is presented.
【学位授予单位】：北方工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU364

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