【作者】 甘志明；

【导师】 李英民； 罗涛；

【作者基本信息】 重庆大学 ， 建筑与土木工程， 2007， 硕士

【摘要】 随着城乡建设的高度发展,高大模板支撑体系在现浇混凝土结构施工中的应用越来越广泛,而扣件式钢管高大模板支撑体系是我国目前使用量最大、应用最普遍的一种模板支撑形式。但由于此类结构设计计算和实际搭设过程中存在着许多不确定、不安全的因素,导致了高大模板支撑体系倒塌事故时有发生,严重影响了施工安全和建筑物的使用性能。现行规范计算方法对扣件式模板支撑体系的设计计算存在着3项比较明显的缺陷,即:(1)荷载的计算没有考虑泵送混凝土的冲击荷载;(2)立杆的计算安全度不足;(3)模板支架的构造措施太宽松,使模板支架只能算是“非几何不可变杆件结构”,达不到计算模式“几何不变杆系结构”的要求。现有的研究成果也存在局限性,主要表现为2个方面:(1)主要侧重于立杆的稳定性的研究,对基础设计没有引起足够的重视;(2)主要是针对高大模板支撑架的计算模式进行研究,较少对实施过程管理中存在的问题进行系统深入的分析研究。本文通在典型工程中的实践,给出了一个完整的实施范例的设计方案;并在该工程中成立了QC小组,针对“确保预应力箱梁高大模板体系的安全”这一课题开展了PDCA循环,采用因果图法找出了导致预应力箱梁高大模板支撑体系失稳的13条末端因素,确定了在该工程条件下的7条要因,提出了相应的对策,通过对策的实施验证了对策的有效性,成功地完成了预应力箱梁的施工,为以后类似工程的施工起到了举一反三的作用。接着,作者根据典型工程分析得到的13条末端因素对广西50个高大模板工程进行了调查,统计出了这13条末端因素在广西建筑施工中的实际情况,发现了合格率低于60%的有2项,即“钢管壁厚不足”与“没有配备扭力板手”,且这两项合格率很低,分别只有0%与2%,需要政府部门、监理单位、施工单位重点关注,并采取相应的对策;合格率在60%～80%有2项,即“没有详细节点构造措”与“钢管弯曲”,这2项需要一般关注;其它9项合格率均在80%以上,需要适当关注即可。本文通过研究系统地总结了规范存在的3个缺陷并提出了修正措施,通过工程实践给出了完整的高大模板支撑体系的设计范例,起到了举一反三的作用;通过在工程中成立QC小组进行PDCA循环活动,首次发现了影响高大模板体系施工质量的13条末端因素并提出了相应的对策;通过对广西50个高大模板工程的调查,发现了影响高大模板工程施工质量的13条末端因素在广西的基本变化规律,提出了政府部门、监理单位、施工单位应采取的改进措施,为扣件式钢管高大模板支撑体系的安全、高效、经济的工作提供了科学依据,为建筑工程的安全施工提供有利的借鉴。更多还原

【Abstract】 With the high development of the construction industry in urban and countryside area, high formwork supporting system is being applied more and more extensively to cast-in-place concrete structure. The high formwork supporting system with fastener-style steel pipe, a style of frame system, is used most widely and in the largest quantity. However, because of some uncertain and unsafe factors during designing calculation and construction, collapses of the high formwork supporting system are frequent, which is harmful to the safety of constructing and the performance of building.When it comes to the designing calculation of the high formwork supporting system with fastener-style steel pipe, there are three apparent bugs in present standard. First, the calculation of load does not take the impulsive force bringing by pumping concrete into account. Second, the calculation of vertical struts doesn’t have needed degree of safety. Third, the structures of the frame system were so loose that it could make the frame a stable no-geometric structure , in stead of a stable geometric structure. Furthermore, there are also two shortcomings in existing research achievements. Firstly, these researches always emphasize the stability of vertical struts and pay little attention to foundation’s design. Secondly, these researches focus on the calculation method and little make a deep and systematic analysis on the managing process.According to the experience getting from a typical project, this article tries to provide a solution. In the project, the author established a QC group and carried out a PDCA cycle which aimed at ensuring the safety of the preload-stressed concrete box beam high formwork system. By using the cause and effect system diagram, the QC group distinguishes 13 terminal elements which can cause the preload-stressed concrete box beam high formwork system to lose stability and defines seven of them as the key elements in the project and then raised the corresponding solutions. After being put into practice, these solutions are proved to be effective. The construction process of preload-stressed box beam’s is accomplished smoothly, which set a good example to other similar projects. Basing on the thirteen terminal elements analyzed from the project above, consequently, the author carries out a study on fifty high-formwork projects in Guangxi. The study shows that in the percent of pass, two items are lower than 60%, e.g. thicknessless of steel tube and no equipping moment tool, moreover, the percent of pass of these two items ranking from 0 to 2%, on which government departments, engineering supervision agencies and engineering companies need to concentrate more attention and take effective measures. 2 items have a percent of pass ranking from 60% to 80%, e.g. having no detailed joint structural measure and the curve of steel tube, which needed to be paying a common attention to. The other nine items’pass percent was better than 80%, to which a proper concentration was enough.After research, this article sums up three bugs existing in present standard and proposes amendments. By practical building, the author provides a whole case on how to design a high formwork supporting system, which set a good example to the other projects. By establishing the QC group and carrying out the PDCA cycle, the thirteen terminal elements that affect the quality of high formwork supporting system constructing are distinguished and corresponding solutions are brought up. By the survey of fifty engineering projects, the variability law of the thirteen terminal elements is found out; according which the author proposes the measures that government departments, engineering supervision agencies and engineering companies should take. This article, in a word, would provide scientific basis for the safety, high efficiency and economical work of the high formwork supporting system with fastener-style steel pipe. It also provides an available reference to the safe construction of civil building.更多还原