当前位置:主页 > 科技论文 > 水利工程论文 >

温降作用下大型箱型倒虹吸横向温度应力计算方法研究

发布时间:2018-07-27 18:49
【摘要】:我国水资源分布的总体趋势是南多北少,为缓解这一问题,提升国民经济发展动力,国家实施南水北调工程。南水北调中线工程于2014年通水,有效缓解华北地区水资源短缺的现状。倒虹吸作为交叉建筑物,在南水北调中使用较多,为满足输水量的需要,大截面多箱室预应力混凝土倒虹吸结构由此诞生,对于埋入式混凝土倒虹吸结构,温度应力不被重视,而对其在施工时的温度应力关注较多,近来已有文献指出温度荷载对埋入式混凝土倒虹吸结构的影响,为此笔者认为有必要关注其温度应力问题。笔者先从简单的单箱室倒虹吸开始,查阅相关文献,在假定倒虹吸板为半无限厚板,气温变化为谐波变化的条件下,得到混凝土倒虹吸温度场的解析解答,取温差为工程控制荷载,由温度场的解析解答简化所得到的温差分布函数,和混凝土铁路桥梁规范中的温差分布函数具有相同的函数类型,这说明了混凝土结构热传导的共性问题,因此笔者将桥梁上面的温差分布函数引用到倒虹吸上。由已知的温差分布函数,计算倒虹吸温度应力,混凝土倒虹吸温度应力分为板厚范围内的自约束应力和结构本身的框架约束应力,其总应力是这两部分应力之和。自约束应力计算公式推导和框架约束应力推导可详见文章相关章节,这里不再累述。有了单箱室倒虹吸的温度应力计算公式,笔者依次对双箱室、三箱室倒虹吸温度应力计算公式进行了推导。在计算多箱室倒虹吸框架约束应力时,结构超静定次数较高,笔者根据结构力学计算得出,多箱室倒虹吸温度应力的计算可以简化成单个箱室的温度应力计算,这一结论大大简化了多箱室倒虹吸温度应力计算,提高了计算公式的实用性。笔者对双箱室、三箱室倒虹吸,分别进行了实例计算,并用ANSYS模拟,通过计算结果和有限元结果对比发现,不管是双箱室倒虹吸还是三箱室倒虹吸,其计算结果均能够和有限元结果吻合,可以推广使用;实例计算还发现,多箱室预应力混凝土倒虹吸结构在施工完成之后,在冬季降温期将产生颇大的温度应力,威胁结构安全,应当在运营过程中加强结构安全的监管。文章最后采用公路桥梁上的折线温差分布函数,推导了折线温差分布下多箱室混凝土倒虹吸结构的温度应力计算公式,并采相同的工程实例进行了计算,对比指数温差分布函数计算结果,两者计算结果相差在10%以内,笔者认为该计算方法可以推广使用。
[Abstract]:The general trend of water resources distribution in China is that the water resources in the south are less than in the north. In order to alleviate this problem and promote the motive force of the development of the national economy, the state has implemented the South-to-North Water transfer Project. South-to-North Water diversion Project opened water in 2014, effectively alleviating the water shortage in North China. As a cross structure, inverted siphon is widely used in the South-to-North Water transfer Project. In order to meet the need of water delivery, the inverted siphon structure of prestressed concrete with large section and multi-chamber is born, and the temperature stress of the buried inverted siphon structure is not paid much attention to. Recently, it has been pointed out that the influence of temperature load on the inverted siphon structure of embedded concrete. Therefore, the author thinks that it is necessary to pay attention to the temperature stress of the inverted siphon structure. The author begins with the simple inverted siphon in a single chamber and looks up the relevant literature. Under the assumption that the inverted siphon plate is a semi-infinite thick slab and the temperature change is harmonic, the analytical solution of the inverted siphon temperature field of concrete is obtained. Taking the temperature difference as the engineering control load, the temperature difference distribution function simplified by the analytic solution of the temperature field has the same function type as the temperature difference distribution function in the concrete railway bridge code. This explains the common problem of heat conduction in concrete structure, so the temperature distribution function above the bridge is applied to the inverted siphon. Based on the known temperature difference distribution function, the inverted siphon temperature stress is calculated. The concrete inverted siphon temperature stress is divided into the self-confined stress in the thickness range of the plate and the frame confined stress in the structure itself, and the total stress is the sum of the two stresses. The derivation of the formula of self-constrained stress and the derivation of frame constrained stress can be found in the relevant chapters of the article, which will not be restated here. With the calculation formula of temperature stress of inverted siphon in single chamber, the author deduced the formula of temperature stress of inverted siphon in two chambers and three chambers in turn. In the calculation of confinement stress of inverted siphon frame in multi-box chambers, the number of statically indeterminate structures is high. According to the calculation of structural mechanics, the calculation of inverted siphon temperature stress in multi-box chambers can be simplified into the calculation of temperature stress in a single chamber. This conclusion greatly simplifies the calculation of temperature stress of inverted siphon in multi-box chambers and improves the practicability of the formula. The author calculates the inverted siphon of two and three chambers respectively, and simulates it with ANSYS. The results are compared with the results of finite element method, and it is found that, whether it is the inverted siphon in the double chamber or the inverted siphon in the three chambers, The calculated results are in good agreement with the finite element results and can be widely used. It is also found that after the completion of the construction of the inverted siphon structure of multi-chamber prestressed concrete, there will be considerable temperature stress during the cooling period in winter. Threats to structural security should be strengthened during the operational process of structural safety supervision. In the end, the formula of temperature stress of concrete inverted siphon structure of multi-box concrete under the distribution of broken line temperature difference is deduced by using the distribution function of broken line temperature difference on highway bridge, and the same engineering example is taken to calculate the temperature stress. Compared with the calculated results of exponential temperature distribution function, the difference between the two results is less than 10%. The author thinks that this method can be popularized.
【学位授予单位】:兰州交通大学
【学位级别】:硕士
【学位授予年份】:2016
【分类号】:TV672.5

【参考文献】

相关期刊论文 前10条

1 季日臣;严娟;苏小凤;;混凝土箱形渡槽日照高温下结构安全研究[J];南水北调与水利科技;2013年06期

2 孙素艳;李原园;杨丽英;;我国水资源面临形势及可持续利用对策研究[J];人民长江;2011年18期

3 许四法;张豪;;农业灌溉水渠防渗土工膜的温度敏感性及张拉力评价[J];农业工程学报;2011年04期

4 赵山;赵湘育;吴泽玉;;矩形渡槽在寒潮作用下温度应力分析[J];人民黄河;2010年04期

5 王正中;芦琴;郭利霞;杨成有;杨富元;;基于昼夜温度变化的混凝土衬砌渠道冻胀有限元分析[J];农业工程学报;2009年07期

6 朱伯芳;;关于混凝土坝的几个新理念[J];水利学报;2008年10期

7 朱伯芳;杨萍;;混凝土的半熟龄期——改善混凝土抗裂能力的新途径[J];水利水电技术;2008年05期

8 王正中;李甲林;陈涛;郭利霞;姚汝方;;弧底梯形渠道砼衬砌冻胀破坏的力学模型研究[J];农业工程学报;2008年01期

9 李学军;费良军;任之忠;;大型U型渠道渠基季节性冻融水分运移特性研究[J];水利学报;2007年11期

10 季日臣;夏修身;陈尧隆;房振叶;;骤然降温作用下混凝土箱形渡槽横向温度应力分析[J];水利水电技术;2007年01期

相关博士学位论文 前2条

1 武立群;混凝土箱梁和空心高墩温度场及温度效应研究[D];重庆大学;2012年

2 刘西军;大体积混凝土温度场温度应力仿真分析[D];浙江大学;2005年

相关硕士学位论文 前1条

1 李彬彬;大体积混凝土温度应力有限元分析[D];西安建筑科技大学;2007年



本文编号:2148814

资料下载
论文发表

本文链接:https://www.wllwen.com/kejilunwen/shuiwenshuili/2148814.html


Copyright(c)文论论文网All Rights Reserved | 网站地图 |

版权申明:资料由用户b143e***提供,本站仅收录摘要或目录,作者需要删除请E-mail邮箱bigeng88@qq.com