大跨径不对称混凝土连续刚构桥病害与处置对策

发布时间：2018-12-19 11:18

【摘要】：大跨径混凝土连续刚构桥是目前我国运用较为普遍和成熟的桥型之一。但由于受地形条件、通航条件等因素的限制,通常会采取不对称布置。不对称连续刚构在受力、变形、配筋及施工等方面异于对称结构。近年来,随着交通量的增长和重载车辆的不断出现,该类桥型容易出现中跨合拢段下挠和梁体不对称开裂等病害(病害位置异于对称结构),直接影响到桥梁结构的安全性及耐久性,亟需对该类病害的处置对策进行研究,主要从以下几个方面进行:通过有限元软件Midas/Civil对不对称连续刚构桥与对称连续刚构桥在结构内力、位移及应力等方面进行比较分析。针对大跨径不对称连续刚构桥出现的中跨合拢段下挠和梁体不对称开裂现象,以云南某大桥为依托工程,从设计、施工及其后期运营等方面进行病害成因分析。采用桥梁有限元软件Midas/Civil对依托工程建立模型,通过对不对称连续刚构桥中跨合拢段持续下挠病害的研究分析,提出采用不对称布置体外预应力钢束的加固设计方案,并对该方案进行加固效果分析。对体外预应力加固施工过程进行有效的控制,通过对应力、变形及裂缝的监控,分析体外预应力加固方案对提高桥梁承载能力、减少跨中下挠、改善桥梁应力状况、抑制裂缝开展等方面的效果,从而为大跨径不对称连续刚构桥的同类型病害处置方法提供对策。
[Abstract]:Long span concrete continuous rigid frame bridge is one of the most popular and mature bridges in China. However, due to the constraints of terrain and navigation conditions, asymmetric arrangements are usually adopted. Asymmetric continuous rigid frame is different from symmetrical structure in force, deformation, reinforcement and construction. In recent years, with the growth of traffic volume and the continuous appearance of heavy-duty vehicles, this kind of bridge type is prone to appear such diseases as deflection in the middle span closure section and asymmetric cracking of the beam body (the position of the disease is different from that of the symmetrical structure). It directly affects the safety and durability of bridge structure, so it is urgent to study the countermeasures to deal with this kind of disease. The main contents are as follows: the internal force displacement and stress of asymmetric continuous rigid frame bridge and symmetrical continuous rigid frame bridge are compared and analyzed by finite element software Midas/Civil. In view of the phenomenon of deflection and asymmetric cracking of beams in the middle span closure section of long-span asymmetric continuous rigid frame bridge, the causes of the disease are analyzed from the aspects of design, construction and later operation based on a bridge in Yunnan Province. The bridge finite element software Midas/Civil is used to establish the model of the supporting engineering. Through the study and analysis of the continuous deflection in the span closure section of the asymmetric continuous rigid frame bridge, the reinforcement design scheme of the asymmetric arrangement of external prestressed steel beam is put forward. The reinforcement effect of the scheme is analyzed. Through monitoring the stress, deformation and crack, the external prestressing reinforcement scheme can improve the bearing capacity of the bridge, reduce the midspan deflection, and improve the stress condition of the bridge. The effect of restraining crack development and so on provides countermeasures for the treatment of the same type diseases of long span asymmetrical continuous rigid frame bridge.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U445.71

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