【作者】 李璐；

【导师】 高睿；

【作者基本信息】 武汉大学 ， 工程管理， 2018， 硕士

【摘要】 预应力施工技术是整个桥梁工程的灵魂所在。现阶段,预应力预制小箱梁在城市高架桥梁和公路桥梁中被广泛应用。预应力预制小箱梁常用的预应力施工技术有后张法、先张法;这些施工工艺都在某些方面有着其独有的优点,同时也都伴随有一些缺陷。为了使桥梁在跨越能力、经济条件、施工工艺上得到一个提升,就需要预应力施工技术进一步的发展。本文提出在预制小箱梁中采用横张法进行预应力筋的施工,即是汲取各施工工艺所长,使小箱梁的预应力施工做到效果上佳,经济节约。本文首先分析了当前预应力混凝土梁的常用施工方法,并以此为基础提出了在小箱梁中使用横张预应力混凝土新技术的概念,同时通过对比及理论分析,探析横张预应力混凝土的特点。并与现有预应力施工技术比较,证明了横张法施工技术其特有的优越性。其次,本文通过理论计算及横张法施工工艺要求,设计出一套横张法施工的图纸,该图纸不仅能满足横张法施工的要求,也保证了其外部尺寸与现有标准小箱梁相同,可达到替代现有标准后张法小箱梁的效果。并根据横张法张拉工艺的要求,开发出了一种新型台座。该台座由底模系统、台座下施工区域、挡土墙共同组成。台座的布置既满足横张施工的需要,也满足模板架设及预拱度的实施。结果表明,本套图纸可以满足横张法施工的要求。之后,本文研究了横张法小箱梁的制作过程难点,对横张法施工的工艺工法进行了详细的分析,提出了一套横张法小箱梁施工方法。同时根据现场施工对方案中的各个步骤做出了说明,提炼出了横张法施工中应控制的关键因素,对其也做了进一步的解释及要求。最终,形成了一套适用于横张法小箱梁的施工方案。最终,通过理论与实际的结合,以及新旧工艺施工状况的对比。证明横张法张拉预应力筋有效地提高了预应力效果,提升了整片梁的质量,从而提高了桥梁结构的安全性和耐久性,具有很高的社会效益。并为其今后的发展方向指明了方向。更多还原

【Abstract】 Prestressed construction technology is the soul of the whole bridge construction.At present,prestressed small box girders are widely used in urban elevated bridges and highway bridges.The prestressed construction technology of prestressed precast box girder has post-tensioning and pretensioning method.These construction techniques have their unique advantages in some aspects,and they are also accompanied by some defects.In order to improve the bridge’s spanning capacity,economic condition and construction process,the prestressed construction technology needs to be further developed.In this paper,the construction of transverse tensioned is put forward in the precast box girder.That is to draw on the director of the construction technology.To make the construction of prestressed box girder to achieve good effect and economical saving.In this paper,the common construction methods of prestressed concrete beams are analyzed.And on this basis the concept of new technology of transverse prestressed concrete in small box girder is proposed.At the same time,through comparison and theoretical analysis,the characteristics of transverse tensioned prestressed concrete are analyzed.Compared with the existing prestressed construction technology,it proves the unique superiority of the transverse tensioned prestressed construction technology.Secondly,this paper adopts the theoretical calculation and the construction process requirements of transverse construction requirements.Design a set of transverse tensioning construction drawings,the drawings can not only meet the requirements of horizontal tensioning construction,also ensures that the external size small box girder with existing standards,and the results can be achieved by replacing the existing standard.A new type of pedestal is developed according to the requirements of the transverse construction.The pedestal is composed of the bottom mould system,the construction area under the pedestal and the retaining wall.The layout of the pedestal can meet the needs of the construction of the transverse and the erection of the template and the implementation of the precamber.The results show that this set of drawings can meet the requirements of the transverse sheet construction.After introducing the construction of a box girder,this paper describes the process construction method of transverse tensioned method and presents a complete set of construction methods of the beam method.At the same time,according to the construction of the site,each step in the scheme is explained,the key factors that should be controlled in the construction of the transverse tensioned prestressed method are extracted,and the further explanation and requirement are made.Finally,through the combination of theory and practice,as well as the comparison between old and new process construction conditions.It proves that transverse tensioned prestressed can effectively improve the prestress effect and improve the quality of the whole beam,thus improving the safety and durability of the bridge structure,and has a high social benefit.In addition,it points out the direction for its future development.更多还原