高速公路宽幅连续刚构桥悬臂施工关键技术研究

发布时间：2019-04-03 08:59

【摘要】：随着我国交通建设的高速发展,我国桥梁施工技术水平也不断提高。宽幅大跨高难度桥梁也不断涌现,连续梁的悬臂浇筑法也日趋成熟。本文主要是依托由中铁十七局集团有限公司承建,福建省三明市长深高速公路连接线A3合同段马林大桥。马林大桥为左右幅分离错位布置式桥梁,右幅桥为(4×26.5+(42+76+42)+3×40+4×30)=514m的现浇预应力砼连续刚构+预应力砼T梁桥；左幅桥为3×30+(42+76+42)+5×40+2×30=523.5m现浇预应力砼连续刚构+预应力砼T梁桥。主桥设计为(42+76+42)=160m预应力混凝土连续刚构桥跨越峡谷；桥面横坡3%。箱梁断面采用单箱双室直腹板断面,箱梁顶板宽25.25 m,底板宽17.25 m,悬臂长度4.0m。本课题主要研究解决该桥施工中地形陡峭,施工道路复杂、运输条件差、现场垂直吊装能力低；桥面设置了3%的超高横坡,主梁为25.25m宽的单箱双室预应力混凝土箱梁,箱梁相邻腹板间桥面高差达25.5cm；主桥桥面宽度25.25m,底板宽度17.25m,在挂篮走行工况下后下横梁的两吊点间距将达到25.5m以上,势必需要大刚度下横梁,才能满足挂篮变形要求。如何优化挂篮下横梁的结构型式或支撑(吊点)的布置形式,实现减小下横梁的截面尺寸,进而降低整个挂篮的重量等设计难题,确保施工安全,高效及成本节约。结合马林大桥在实际施工过程中需要解决的技术难题,采用理论分析、数值模拟、专家论证、室内试验、现场实验及监测等方法,针对马林大桥异型三角挂篮的设计与优化、主梁悬臂施工风险分析与风险控制四个方面进行了研究,主要取得以下几个方面的研究结论：(1)综合三角和菱形挂篮各自优点,研究设计了一种新型挂篮形式——异形三角挂篮；优化异形三角挂篮主桁架设计,主桁架的受拉构件采用强度更高的16Mn钢拉板代替以往的型钢结构,节约钢材；同时采用销轴及螺栓联结主构件简化了拼装工艺。通过三片主桁架阶梯式布置和连接解决宽梁面大横坡带来的相邻榀主桁架之间的高差问题,提高了挂篮的通用性及利用率。(2)通过在挂篮底横梁增设纵向滑移梁作为下横梁的支撑构件,有效减小下横梁的受力跨度,解决了宽幅梁悬臂施工需要大刚度下横梁的难题,同时也提高了挂篮走行过程中的安全性。(3)创新性地提出多榀桁架挂篮前上横梁错台铰接连接形式(布置方法),解决了大横坡宽幅桥面挂篮三片主桁架高差问题,满足了挂篮整体稳定及走行要求。最后,通过本项目的研究,解决了马林大桥同时具有高墩、超宽梁面、桥面大横坡及运输吊装困难等多种因素对主桥挂篮的设计与施工提出的难题,获得了显著的社会经济效益。
[Abstract]:With the rapid development of our country's traffic construction, the bridge construction technology level of our country is also continuously improved. Wide-span, large-span and high-difficulty bridges are emerging, and the cantilever casting method of continuous beams is maturing day by day. This article is mainly relying on the construction by China Railway Seventeen Bureau Group Co., Ltd., Sanming City, Fujian Province, Changshen Expressway Link A3 contract section Malin Bridge. Ma Lin Bridge is a dislocated bridge with the left and right sides separated. On the right side, it is a cast-in-situ prestressed concrete continuous rigid frame prestressed concrete T-beam bridge with (4 脳 26.5 (4276 42) 3 脳 40 4 脳 30) = 514m. The left bridge is 3 脳 30 (427642) 5 脳 402 脳 30 脳 523.5m cast-in-situ prestressed concrete continuous rigid frame prestressed concrete T-beam bridge. The main bridge is designed to (427642) = 160m prestressed concrete continuous rigid frame bridge crossing the canyon, and the deck slope is 3%. The section of box girder is single box and double compartment straight web section, the roof width of box girder is 25.25 m, the width of bottom plate is 17.25 m, and the length of cantilever is 4.0 m. In the construction of this bridge, the terrain is steep, the construction road is complicated, the transportation condition is poor, and the vertical hoisting capacity is low. The bridge deck has 3% ultra-high cross slope, the main beam is 25.25m wide, single box and double chamber prestressed concrete box girder, and the bridge deck height difference between adjacent web of box girder is up to 25.5 cm;. The width of the deck of the main bridge is 25.25m and the width of the floor is 17.25m. Under the running condition of the hanging basket, the distance between the two hanging points of the rear lower beam will reach more than 25.5m. It is bound to require a large stiffness of the cross beam in order to meet the requirements of the deformation of the hanging basket. How to optimize the structure type of the lower beam or the arrangement form of the support (suspension point), to reduce the cross-section size of the lower beam, and then to reduce the weight of the whole hanging basket, so as to ensure the safety of construction, high efficiency and cost-saving. Combined with the technical problems needed to be solved in the actual construction process of Ma Lin Bridge, the design and optimization of the shaped triangle hanging basket of Ma Lin Bridge are designed and optimized by using the methods of theoretical analysis, numerical simulation, expert demonstration, indoor test, field experiment and monitoring, etc. The risk analysis and risk control of cantilever construction of main beam are studied in four aspects. The main conclusions are as follows: (1) the advantages of triangle and rhombic hanging basket are synthesized, and the results are as follows: (1) combining the advantages of triangle and rhombic hanging basket, In this paper, a new type of hanging basket is studied and designed, which is called special-shaped triangular hanging basket. To optimize the design of the main truss of the special-shaped triangular basket, the tensile member of the main truss is replaced by 16Mn steel drawing plate with higher strength, which saves steel, and the assembly process is simplified by using the pin shaft and bolt connection main member. Through the arrangement and connection of three main trusses, the problem of height difference between adjacent main trusses caused by wide beam and large transverse slope is solved. The generality and utilization ratio of the hanging basket are improved. (2) by adding longitudinal sliding beam to the bottom of the hanging basket as the supporting member of the lower cross beam, the force span of the lower cross beam is effectively reduced. The problem of large stiffness beam in cantilever construction of wide-width beam is solved, and the safety in walking process of hanging basket is also improved. (3) the hinge connection form (layout method) of wrong cross beam in front of truss hanging basket is put forward creatively. The problem of the height difference of three main trusses is solved, which meets the requirements of the overall stability and running of the basket. Finally, through the research of this project, the difficult problems of the design and construction of the main bridge hanging basket are solved by many factors, such as the high pier, the super wide beam surface, the large transverse slope of the bridge deck and the difficulty of transportation hoisting, etc. Remarkable social and economic benefits have been obtained.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U445.4

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