【作者】 孙小鸾；

【导师】 孙伟民；

【作者基本信息】 南京工业大学 ， 结构工程， 2006， 硕士

【摘要】 为了进一步节约耕地,保护现有土地资源,国家制定一系列的墙改措施和政策,限制粘土砖的使用,推广一系列新型墙体材料,包括混凝土空心砌块、粉煤灰硅酸盐砌块、页岩烧结砖等,然而在推广过程中,不仅多层承重砌体房屋墙体普遍存在裂缝问题,框架结构中砌体填充墙开裂问题也相当严重。而框架填充墙与梁柱边界裂缝一旦形成就会降低填充墙的整体性、耐久性和抗震性能,影响着建筑物的使用功能,特别是随着我国墙材改革、住房商品化的进展,人们对居住环境和建筑质量的要求不断提高,对建筑物墙体裂缝控制的要求更为严格。因此加强砌体填充墙,特别是新材料砌体填充墙的抗裂研究,已成为工程界、国家行政主管部门以及房屋开发商共同关注的课题。本文依照“实际调查,归纳裂缝的形式和位置—理论求解方法分析,明确求解途径—有限元模拟,分析裂缝开展情况—有限元与实际相对比,探索有限元分析的可行性—提出防治对策的一些建议”的思路分别做了下面的一些工作:首先对南京工业大学江浦校区内的几座开裂较为严重的教学楼以及南京大地集团的几座在建的框架建筑进行了裂缝的调查,归纳总结出填充墙裂缝的形式和分布情况,结合已有的经验,初步探索形成裂缝的主要原因。在有限元分析阶段,首先借鉴了浙江大学在做砌块建筑墙体的温度裂缝分析中的经验,将温度荷载等效于作用在框架梁上的水平荷载,同时考虑上部填充墙的重量,分别对五种填充墙形式进行抗侧力的对比,通过比较侧移变化、荷载位移曲线以及刚度退化等,间接地获得各种墙体形式的抗裂性能。其次,同时考虑温度和干缩的作用,对五种填充墙按时间步施加降温荷载,采用整体法考虑砌块与砂浆组成的墙体,从各种墙体随温差荷载增加时裂缝的开展情况可以很直观地看出各自墙体抗裂性能的优劣。再次,分别考虑砂浆与砌块的材料非线性,采用分离式建模。研究砂浆等级、砂浆厚度、温差的作用方式、面层构造以及窗洞对填充墙变形或裂缝开展的影响,分析的结果与实际的情况比较吻合。有限元分析的最后,按1:1的实体模型,对调查的建筑进行整体有限元模拟,采用Solid65实体单元建模,得到温度应力在建筑各处填充墙的大小与分布情况。在此基础上,进行了不同跨度、层数,不同工况的13种模型的对比分析,找出跨度、层数以及工况对结构整体侧移和应力分布的影响。文章的最后结合有限元分析的结果,以及以往填充墙抗裂成果,建议性的提出填充墙裂缝的防治方法以及对已有的裂缝的补救方法。更多还原

【Abstract】 For the sake of saving plowland and protecting land resource further, Country made a series of policy on wall innovation to limit the utilication of clay bricks and popularized a series of new wall materials. But while in the process of generalization, cracks occour at large not only in muti-floor bearing block building but also in infilled wall of frames. Whereas the formation of cracks between wall and beam (colume) will reduce the integration, durability and earthquake resistance of wall, which will affact the using function of buildings. In particular, as innovation of wall matieral and houce merchandizing progresses, people make more request on living entironment and building quality, such as bringing the cracks of wall under control. So it has attacted more attention of engineering, department of country executive administrations and the estate developer to enhance the cracking research on infilled wall, especially on new material wall.In this paper, such work was finished as follow in term of live investigation(concluding cracks’shape and location ), questing for theoretics method (conforming solution method ), finite element analysis(analysing developing of cracks ), results comparison between finite element analysis and investigation (conforming the feasibility of finite element analysis ).Firstly, cracking investigation was done in some teaching buidings of Nanjing Univercity of Technology. The shape and distribution of cracks was concluded and the main reason of these cracks was brought forword according to existing experience.On the finite element analysis stage, horizontal force was location on the beam of frame instead of temperature force firstly. Similar method was used by Zhejiang University on experimental research of temperature cracks on masonry wall.Considering above weight of block wall at the same time, comparison of side-displacement-resistant among 5 models, which have difference in formation, was done. Cracking-resistance of each model was obtained indirectly though comparing variety of side–displacement, loading-displacement curve, stiffness degeneration curve.Temperature load was applied on 5 models of different formation, considering temperature and shrinkage effeect at the same time. In these models, the wall composed of mortar and block was treated as whole. Though the process of cracking development of each different wall, we can obtain their capability of crack-resistant更多还原