正常使用极限状态下考虑二阶效应问题裂缝宽度计算方法研究

发布时间：2018-06-14 18:56

本文选题：钢筋混凝土 + 二阶效应　；参考：《重庆大学》2014年硕士论文

【摘要】：谈到二阶效应，人们通常提及的是承载力极限状态下结构的二阶效应。从国内外20世纪至今较为集中的研究来看，也主要是针对承载力极限状态下结构二阶效应的研究。但随着现代化工业的发展，混凝土结构朝大跨度、大空间方向发展，加之高强钢筋逐渐普及化的使用，使得正常使用极限状态逐渐成为结构设计的控制指标。因此研究二阶效应在正常使用极限状态下对结构的影响规律就显得非常必要了。本论文基于标准规范科研项目“对《混凝土结构设计规范》GB50010-2010二阶效应设计方法后续问题的研究”的遗留问题之一展开进一步的研究工作，，即该规范中正常使用极限状态下偏心受压构件最大裂缝宽度计算中考虑二阶效应方法与承载力极限状态下考虑二阶效应方法的严重脱节。为了解决这种同一本规范在两种状态下考虑二阶效应方法的严重脱节，本论文主要作了如下几点工作及探讨：（1）归纳总结我国1989年版、2002年版及2010年版规范及规程在承载力极限状态下对二阶效应的考虑和正常使用极限状态下偏心受压构件最大裂缝宽度验算时对二阶效应考虑的规定，说明了这几版规范中有关二阶效应规定的特点，对各版规范及规程有关二阶效应的背景情况进行分析和理解。对2010年版规范中二阶效应设计方法的后续问题进行了归纳，指出在正常使用极限状态下极易造成工程界误解至今未纠正的考虑二阶效应的条文规定，说明规范中验算偏压构件最大裂缝宽度时考虑二阶效应方法的不合理。（2）归纳总结了钢筋混凝土构件裂缝研究的背景知识，通过分析说明应用混凝土结构设计规范偏心受压构件最大裂缝宽度计算公式验算偏心受压构件最大裂缝宽度所需的前提条件。（3）对变形裂缝专题研究组负责单位当时进行的一系列混凝土偏心受压柱裂缝试验进行归纳总结。在试验数据的基础上，用混凝土结构设计规范最大裂缝宽度计算公式对这一系列偏心受压柱的最大裂缝宽度进行验算并与试验数据对比分析。（4）建立正常使用极限状态下柱子裂缝宽度验算时需考虑二阶效应的结构模型，对该结构在正常使用极限状态下的柱子裂缝进行分析。用2010年版规范裂缝宽度计算公式对柱子的裂缝宽度进行验算，并对验算结果进行分析总结。（5）用有限元分析软件ETABS9.7.4对二阶效应在正常使用极限状态下对结构的影响规律进行了分析，同时对2010年版规范中在正常使用极限状态下采用η-l0法考虑二阶效应的适用性进行了考察。（6）通过归纳、总结、理论分析后提出三种可供规范组选用的正常使用极限状态下验算偏心受压构件最大裂缝宽度时考虑二阶效应的设计条文建议。
[Abstract]:When it comes to the second order effect, people usually refer to the second order effect of the structure under the ultimate state of bearing capacity. The research on the second order effect of the structure under the ultimate bearing capacity is also the focus of the domestic and foreign researches in the 20th century. But with the development of modern industry, the concrete structure is developing towards the direction of large span and large space, and the use of high strength steel bar is popularizing gradually, which makes the limit state of normal use gradually become the control index of structural design. Therefore, it is necessary to study the influence of the second order effect on the structure under the normal limit state. This thesis is based on one of the remaining problems of the second order effect design method of GB 50010-2010, which is one of the scientific research projects of the standard code for the design of concrete structures. That is, the second order effect method is considered in the calculation of the maximum crack width of eccentrically compressed members in the normal use limit state of the code and the second order effect method is considered in the limit state of bearing capacity. In order to solve the serious disconnection between the second order effect method of this same specification in two states, The main work of this paper is as follows: 1) summarize the second order effect and normal use limit state of the codes and regulations in China's 1989 edition, 2002 edition and 2010 edition under the limit state of bearing capacity. The rules of considering the second order effect when checking the maximum crack width of down-eccentrically compressed members, This paper explains the characteristics of the second-order effect in these editions, and analyzes and understands the background of the second-order effect in each edition of the specification and the rules. This paper sums up the following problems of the second-order effect design method in the 2010 edition of the Code, and points out that under the normal limit state of use, it is easy to cause misunderstandings in the engineering circles so far and the provisions considering the second-order effect are not corrected. This paper illustrates the irrationality of the second-order effect method in checking the maximum crack width of the biasing member in the code. Through analysis, the prerequisite for calculating the maximum crack width of eccentrically compressed members by using the calculation formula of maximum crack width of eccentrically compressed members in the code for design of concrete structures is explained. A series of concrete eccentrically compressed column cracking tests were conducted at that time. Based on the experimental data, The maximum crack width of this series of eccentrically compressed columns is calculated by calculating the maximum crack width formula of concrete structure design code and compared with the test data. The second order effect structural model should be taken into account when checking the crack width. The crack of the column in the normal service limit state of the structure is analyzed. The crack width of the column is checked with the formula for calculating the crack width of the 2010 edition of the standard. The results of checking calculation are analyzed and summarized. (5) the influence of second-order effect on the structure under the limit state of normal use is analyzed by using the finite element analysis software ETABS9.7.4. At the same time, the applicability of 畏 -l0 method to consider the second order effect in the standard of 2010 edition is investigated. After theoretical analysis, three kinds of design provisions which can be selected by the code group to consider the second order effect in checking the maximum crack width of eccentrically compressed members under the limit state of normal use are proposed.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU311.4

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