钢管混凝土悬带拱桥受力性能研究

发布时间：2018-01-11 14:11

本文关键词：钢管混凝土悬带拱桥受力性能研究　出处：《福州大学》2014年硕士论文　论文类型：学位论文

【摘要】：拱桥和索桥的历史悠久,利用二者各自的优势,取长补短组合形成的悬带拱桥,是近年来新出现的一种结构形式。结合钢管混凝土拱,提出钢管混凝土悬带拱桥新桥型,降低了对基础的要求,并将自锚式拱桥中受压传力斜杆简化成为桥台的一部分,提高了结构的利用效率,具有结构受力合理、桥型轻巧美观等优点。为了解该桥型的力学特性和计算方法,本文开展了该桥型的设计计算、施工监控和参数分析,主要工作与研究成果有：(1)开展一座钢管混凝土悬带拱桥的设计与计算分析,并按照国内现行的规范规程对钢管混凝土悬带拱桥不同受力构件或结构进行了验算。验算结果表明,设计桥梁结构的受力性能均可满足规范要求。(2)结合已有的悬带桥和钢管混凝土拱桥的设计和建模思路,提出了适合于该桥型的建模方法。(3)开展了实桥的施工监控。结果表明,各个主要施工工况下实测的拱肋挠度、应力变化规律和有限元模型计算结果吻合较好,验证了该建模方法的正确性。(4)借鉴传统桥梁施工预拱度设置方法,进行钢管混凝土悬带拱桥的拱肋结构预拱度的设置。结果表明,钢管拱肋成桥阶段的线形与模型计算结果吻合较好,表明这种预拱度设置方法是合理可行的。(5)通过算例分析了国内现行的规范规程规定的施工精度控制指标对钢管混凝土悬带拱桥的钢管拱肋的适用性。结果表明,拱肋和悬带的最大线形偏位对桥梁结构受力性能影响很小,说明其施工精度控制指标可应用于钢管混凝土悬带拱桥。(6)利用已验证过的有限元模型开展结构设计参数分析。结果表明,随着矢跨比增加,拱脚轴力、悬带轴力和结构对桥台的推力均逐渐减小；拱肋外倾角增大会降低拱结构对悬带结构的支撑作用,导致拱脚轴力和推力的下降,而悬带轴力、悬带与拱肋位移均有所增加,且拱肋外倾角度增加还会使得结构的稳定性降低,失稳模态从面外失稳变为面内失稳；提高拱结构对悬带结构的支撑比例对于减小拱肋位移、悬带最大位移和悬带轴力也有较大的作用,但会使结构对基础的推力增大,可通过加大预张力来抵消这一不利影响；随着桥面板厚度的增加,对于总体结构的受力均产生不利影响,在压应力允许范围内,宜采用高强轻薄的桥面板；悬带结构铰接和固结情形下对结构受力的影响几乎可以忽略；现浇悬带板可减小成桥的悬带位移且提高结构稳定性。
[Abstract]:The arch bridge and the cable bridge have a long history. The sling arch bridge which is formed by the combination of the two advantages is a new structural form in recent years, combined with concrete filled steel tube arch. The new bridge type of concrete filled steel tubular suspension arch bridge is put forward, which reduces the requirement of foundation, and simplifies the oblique bar of pressure transmission in self-anchored arch bridge as a part of abutment, which improves the utilization efficiency of the structure and has reasonable structural force. In order to understand the mechanical characteristics and calculation method of the bridge type, the design calculation, construction monitoring and parameter analysis of the bridge type are carried out in this paper. The main work and research results are as follows: 1) the design and calculation of a concrete-filled steel tubular sling arch bridge is carried out. In accordance with the current domestic codes and regulations, the different members or structures of CFST sling arch bridge are checked and calculated. The results show that. The mechanical properties of the design bridge structure can meet the requirements of the code. 2) combined with the existing suspension bridge and concrete filled steel tube arch bridge design and modeling ideas. The construction monitoring of the bridge is carried out. The results show that the deflection of arch rib is measured under the main construction conditions. The stress variation law is in good agreement with the finite element model calculation results, which verifies the correctness of the modeling method. 4) the traditional bridge construction pre-arch setting method is used for reference. The results show that the alignment of steel tube arch ribbed bridge is in good agreement with the model calculation results. This method is reasonable and feasible. This paper analyzes the applicability of the construction precision control index of the current domestic code to the steel tube arch rib of the concrete-filled steel tubular sling arch bridge through a numerical example. The results show that the construction precision control index is applicable to the concrete filled steel tube arch bridge. The maximum linear deflection of arch rib and sling band has little effect on the behavior of bridge structure. It is shown that the construction precision control index can be applied to the concrete filled steel tube sling arch bridge. The structural design parameters are analyzed by using the verified finite element model. The results show that the axial force of the arch foot increases with the increase of the rise-span ratio. The axial force of suspension belt and the thrust of structure on abutment decrease gradually. The increase of external inclination angle of arch rib will reduce the supporting effect of arch structure on the sling structure, and lead to the decrease of axial force and thrust of arch foot, while the axial force of suspension band, suspension belt and arch rib displacement will increase. The stability of the structure will be decreased with the increase of the external inclination of the arch rib, and the instability mode will change from the out-of-plane instability to the in-plane instability. Increasing the support ratio of arch structure to sling band structure can reduce the displacement of arch rib, the maximum displacement of suspension band and the axial force of suspension band, but it will increase the thrust of the structure to the foundation. This adverse effect can be offset by increasing pretension; With the increase of the thickness of the bridge deck, the stress of the whole structure will be adversely affected. Within the range of compressive stress, it is advisable to adopt the high-strength and light-weight deck. In the case of hinged and consolidated sling structure, the influence on the stress of the structure can be almost ignored. The cast-in-place sling slab can reduce the suspension displacement of the bridge and improve the stability of the structure.
【学位授予单位】：福州大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U441;U448.22

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