【作者】 田广林；

【导师】 胡长明； 蔺石柱；

【作者基本信息】 西安建筑科技大学 ， 建筑与土木工程， 2008， 硕士

【摘要】 本文以赤峰国际会展中心多功能厅楼盖后张法有粘结预应力混凝土大梁结构体系作为研究实例,总结了国内关于超大跨度预应力混凝土梁的施工技术。首先,本文对高大模板支撑体系的选型作了优化,采用了常用的扣件式钢管脚手架支撑体系,施工中做了详尽的设计验算,采取了合理的构造措施,并从工期、安全、成本三方面综合考虑,提出了高大模板支撑体系设计选型时,应结合混凝土梁实际体型以及施工企业自身的技术力量,宜优先采用通用性强、安全可靠、经济成本相对较低的扣件式钢管脚手架。其次,在后张法预应力结构工程施工中,重点分析了预应力损失的原因,从锚具选型到张拉工艺,提出了超大跨度预应力混凝土梁张拉工艺均要采取两端对称张拉工艺,张拉力用伸长值校核时宜控制在0～±5%,防止结构出现张拉裂缝。再次,针对大体积混凝土梁施工中容易产生温度收缩裂缝,论文从裂缝产生的原因入手,找到控制裂缝的措施。从配合比的优化、原材料的选用到合理控制分层浇注的厚度,从降低混凝土入模温度到加强养护,得出只有合理的施工组织、正确的施工方案和有效的温控监测方案,才是保证大体积混凝土梁质量的关键。最后,对预应力大梁的钢筋骨架安装进行了研究,提出对梁底受力钢筋保护层、钢筋骨架临时支撑、接头等应采取的具体措施,解决了安装大梁钢筋骨架常见的施工难题。本文对超大跨度预应力混凝土梁五个方面的施工技术进行了研究,通过实例应用,取得了较好的综合经济效益,具有较强的指导作用,也对类似工程施工具有一定的推广应用价值。更多还原

【Abstract】 This article takes Chi Feng international convention center multi-purpose hall ceilings which used post-tensioning prestressed concrete beam structure system as example, to summarize the super large-span prestressed concrete beams construction technology.First, this article has optimized the high template support system’s shaping, used the commonly used buckle type steel pipe scaffold support system, made the exhaustive design checking calculation, and used the reasonable structure measure, considered from time, security and cost three aspects , proposed when designing big template support system shaping, it should unify the concretes beams actual shape as well as the construction enterprise own technical force, use the versatility strongly, safe reliable, the relatively low economic cost buckle.Second, in the post-tension prestressed construction, it has taken the corresponding countermeasure after the selective analysis of prestressed loss reason. From the anchorage’s shaping to the pull craft, proposed super large-span prestressed concrete tensioning the craft must pull from both sides symmetrically, the tension force examined with the elongation value should be controlled in the range of 0～±5 % ,to prevent pull crack in the structure.Third, to the temperature shrinkage fracture easy producing in mass concrete beams, we started with the reason of the crack to find the crack controlling measure. From the mixture ratio optimization, the selection of raw material to the reasonable control lamination casting thickness; From reducing the temperature of concrete before entering templet to strengthening maintenance, obtains that only the reasonable construction organization ,the correct plan of construction and the effective controls temperature plan are the key of mass concrete quality.Finally, conducts the research to the prestressed concrete beam’s steel bar skeleton installment, proposed to breast working reinforcement protector, steel bar skeleton temporary support, attachment and other specific measures, has solved the installment beam steel bar skeleton common difficult problem.This article has studied the construction techniques of super large-span prestressed concrete beams five aspects. Through the example application, it has made the good comprehensive economy progress, has the strong instruction, also has certain promotion application value to the similar project construction.更多还原