支井河大桥施工过程照片

大小井上飘彩虹文/贵州省公路局 张祥兵随着最后一节钢管吊装就位，6月30日上午11时许，横跨贵州省罗甸县沫阳镇董当乡大井村大井河上空的平塘至罗甸高速公路大小井特大桥主拱圈顺利合龙，成为目前世界最大跨径山区上承式钢管混凝土拱桥。

贵州首座完全自主建设的世界级大桥大小井风景区上空，两山相峙。

青山绿水之间，横跨南北的大小井特大桥凌空飞架，宛若一道绚丽的彩虹。

作为贵州余庆至安龙高速公路平塘至罗甸段的控制性工程，大小井特大桥自2016年6月29日开工建设，合同工期38个月，概算投资3.7亿元。

大桥全长1.5公里，主桥主跨450米，引桥采用40米装配式组合T梁建设，是世界最大跨径山区上承式钢管混凝土拱桥。

大桥桥台所在山坡峰顶与河底——大小井特大桥合龙 “世界桥梁博物馆”再添新员相对高差约250米，是名副其实的空中“天路”。

目前，“世界桥梁博物馆”中，贵州已经汇集了北盘江大桥、清水河大桥、鸭池河大桥等世界级桥梁，这些超级工程的背后都有中国交建等企业的投入。

不同的是，大小井特大桥由贵州省公路开发有限责任公司投资建设，贵州桥梁建设集团有限责任公司、贵州路桥集团有限公司联合施工，是贵州本土企业完全自主建设的第一座世界级大桥。

“平罗高速大小井特大桥合龙成功！”6月30日，随着贵州省交通运输厅总工程师潘海宣布，“贵州桥”又一次刷新世界纪录，在“世界桥梁博物馆”中，贵州再收录一件新“藏品”。

“世界级难题”成功破解“山区建桥，首选拱桥。

但拱桥的施工工艺比斜拉桥更复杂。

”贵州桥梁建设集团有限责任公司总工程师张胜林说，作为我国典型的高山峡谷大跨度钢管拱桥和世界同类型的桥梁之最，大小井特大桥结构、技术复杂，质量要求高，施工难度更大。

拱座施工现场地形陡峭，边坡开挖高度高，开挖方量大，大体积混凝土温度控制技术难度大，拱脚预埋件安装精度要求高；缆索吊机安装施工主塔拼装高度高，主索安装跨度大，施工安全风险高；主拱安装施工拱肋纵向运输距离长，吊装重量大，主拱对接精度、线形及高程控制要求高，主拱悬拼施工时间长，斜拉扣挂施工难度高；山区机制砂C60自密实混凝土技术难度高，混凝土顶升度高……张胜林一口气数出一串大小井特大桥的难点，随着大桥的合龙，这些难点被建设者们一一破解。

支井河特大桥WJLQ 3 000 kN型无塔架缆索起重机设计与施工何锦章【摘要】沪蓉国道主干线湖北沪蓉西(宜昌至恩施)高速公路支井河特大桥主桥为1430 m上承式钢管混凝土拱桥,其钢管拱肋节段采用WJLQ 3 000 kN型无塔架缆索起重机进行安装,介绍其工作原理、技术参数、设计要点及安装调试等,为大跨度、大吨位缆索起重机的设计与施工提供借鉴.【期刊名称】《铁道标准设计》【年(卷),期】2008(000)001【总页数】5页(P54-58)【关键词】公路桥;无塔架缆索起重机;设计;计算要点;施工【作者】何锦章【作者单位】中铁十三局集团第一工程有限公司,辽宁大连,116033【正文语种】中文【中图分类】U448.221 工程概述图1 缆索起重机总体布置(单位：m)湖北沪蓉西高速公路支井河特大桥全长545.54 m,其主桥为1-430 m上承式钢管混凝土拱桥,计算矢高为78.18 m,矢跨比为1/5.5。

主拱肋为钢管混凝土主弦杆和箱形钢腹杆组成的空间桁架结构,拱脚截面高度13 m,拱顶截面高度6.5 m,上下游两道拱肋平行布置,肋宽4 m,肋间距13 m,每道肋由上、下各2根φ1 200×35(30、24)mm的钢管弦杆组成,并通过上下横联、腹杆及横向斜杆组成空间稳定体系,肋间设20道“米”字撑横联。

因受到施工空间及运输条件的限制,拱肋共分成30个吊装节段和1节合龙段,吊装节段长度在26.226～14.046 m，设计合龙段长60 cm。

水平投影最长为21.639 m(第一节段),节段最大吊重达2 800 kN(双肋)。

节段间采用“先栓后焊、栓焊结合”的连接方式。

本桥主拱肋安装利用缆索起重机,采用“两岸对称悬拼、齐头并进至跨中合龙的斜拉扣挂法”施工。

整个吊装系统由缆索起重机系统和斜拉扣挂系统组成。

2 WJLQ3 000 kN型无塔架缆索起重机2.1 概况缆索起重机设计跨径756 m,单钩起吊能力750 kN,额定起重量为4×750=3 000 kN。

支井河特大桥钢管主拱肋安装方案1.桥梁概况支井河特大桥位于湖北省巴东县野三关镇支井河村一组，大桥横跨支井河峡谷，谷深755米，两岸桥头与隧道紧密相连，场地狭窄，地势险要，交通运输条件极其恶劣，施工难度为沪蓉西高速公路全线之最。

大桥中心桩号为K120＋433.507，全长545.54米，桥跨布置为36m(引桥)+444.8m(主桥)+ 2×27.3m(引桥)。

引桥采用箱型钢筋砼简支梁，主桥为1-430m上承式钢管砼拱桥，计算矢高为78.18m，矢跨比为1/5.5。

主拱肋为钢管混凝土主弦杆和箱形钢腹杆组成的空间桁架结构，拱脚截面高度13m，拱顶截面高度6.5m，上下游两道拱肋平行布置，肋宽4m，肋间距13m （中－中），每道肋由上、下各两根φ1200×35(30、24)毫米的钢管弦杆组成，并通过上下横联、腹杆及横向斜杆组成空间稳定体系，肋间设20道米撑横联。

因受到施工空间及运输条件的限制，拱肋共分成30个吊装节段，节段长度在0.6～26.266米之间,水平投影最长为21.639(第一节段)，节段最大吊重约270T(双肋)。

节段间采用“先栓后焊、栓焊结合”的原则连接。

本桥主拱肋安装利用缆索吊装系统，采用“两岸对称悬拼、齐头并进至跨中合龙的斜拉扣挂法”施工。

缆索吊装系统由缆索吊机系统和斜拉扣挂系统组成。

2.缆索吊机系统本桥利用一台“WJLQ3000KN型无支架缆索起重机”承担主拱肋、拱上立柱、钢盖梁以及箱梁等吊装任务。

该缆索起重机设计跨径756米，单钩起吊能力为75T，额定起重量为4×75T=300T；采用重力式地锚，为钢筋砼结构；主承重索采用由20根φ62mm钢丝绳组成的“单跨双索制”；采用“螺旋式摩擦卷扬机”和“增力式运行小车”作为运行和起升机构，动力源为4台28T双筒慢速卷扬机和4台10T单筒快速卷扬机；牵引速度0.36m～10m/min，起升速度0.26～3m/min，位移精度达到1mm；总设计寿命为12500小时，工作级别为A7级。

1 INSTRUCTIONSZhiJing River Bridge ,located in Sanguan Town, Badong County, is part of Shanghai-Chengdu National Highway System which crosses Hubei Province and connectes Yichang and Enshi. The total length of the bridge is 545.54m, while the main bridge is CFST arch bridge with a span of 430m. The main bridge cross the ZhiJing valley with steep cliffs. The peak elevation of ZhiJing valley is 1415m, while the bed elevation is 660m. The elevation difference is 755m. The valley river bed is 30m wide. The construction condition is extremely poor because of the extremely rough topography.Figure 1 : ZhiJing River Bridge Bridge layoutBridge site climate is subtropical which is humid continental climate zone in hot summer, plentiful sunshine, rainfall abundant, short duration of cold, fog and humid weight, the maximum relative humidity is over 85%, regional rainfall is large, annual average temperature is 17.4 ℃, extreme maximum temperature is 41.6 ℃, extreme minimum temperature is -15.2℃. In winter snow line elevation of Enshi Mountain is about 900~1000m, above the snow line the frost damage and snow damage is much more serious, the bridge located at 945~957m above sea level, and in a large canyon Taniguchi, the ice damage, snow damage, fog damage and other disastrous weather damage in winter are frequently.Bridge design speed is 80Km / h, load rating for the automotive is super -20 level, trailer -120, deck width is 24.5m. Seismic fortification intensity is level Ⅵ, and the design level is Ⅶ.Design of Hubei Zhijing River BridgeYuancheng Peng and Yiqian Li CCCC Second Highway Consultants Co. Ltd., Wuhan, ChinaXiaohong LongSchool of Civil Engineering & Mechanics, Huazhong University of Science & Technology, Wuhan, ChinaABSTRACT: This paper introduces the design and principal technical features of the Zhijing River Bridge, which is the most complicated engineering project on Yichang-Enshi Expressway in Hubei Province, China. It is a long-span hingeless deck-type concrete-filled-steel-tube trussed arch bridge. The main truss arch reachs 421.833m net span and was erected by a cable-shifting and cable-stayed system. The arch was consisted of two trusses, bracing plane frames and several cross struts. The members were first fabricated in factory, and then transported to the site by truck, assembled into segmental trusses, and finally lifted to the designated position by the cable-shifting system. The columns and cap-beams are steel boxes, and the deck system is of 21~21.4m first-simply-supported-then-continued prestressed concrete box girders. The bridge has been completed in October, 2009.168 ARCH’10 – 6th International Conference on Arch Bridges 2 THE MAIN BRIDGE STRUCTURE DESIGNIn the preliminary and technical design phase, two schenes were considered. One is a 450m concrete filled steel tubular (CFST) arch bridge, and the other is a 676m suspension bridge using tunnel anchor technology.According to geological surveys and research on tunnel anchor, the two sides are well developed in rock cracks unloading. The unloading relaxation width is large (approximately 45m) and there is 3 large fissures at Enshi shore. Therefore the tunnel-type anchor is difficult to set up, and the gravity anchorage also can not be adopted because of steep terrain of both shores.At last, the arch bridge is recommended to be adopted as the solution in this project. The situation of constructional impairment and the difficulties of construction were considered at the construction drawing design stage. The preliminary design of the 450-meter arch bridge’s abutment location and the span ratio has been adjusted based on the technical design, 430m main span of the arch program is adopted, so that No. L3 cracks of Enshi shore is avoided.The span of main arch is 430m, cross the bridge arch on a total of 21 holes, span of 19.1m +19 ×21.40m +19.1 m, Yichang shore Approach to 1-36.0m, Enshi shore Approach for 2-27.3m. Full-bridge is located -1.89% ~-2.09% one-way cross-slope and 2% Zongpo two-way cross-slope.2.1 The main arch ribs and arch seatThe span of arch rib is 430m, arrows high is 78.18m, span ratio is 1/5.5, is composed of concrete filled steel tubular main chords. The box-shaped steel belly bar space truss structure, the section height of rib vault reaches 6.5m, while arch foot reaches 13m; the spacing between two ribs is 13m (in the - middle), the horizontal width of rib is 4m. Every rib made from the upper and lower of two ф1200 × 35 (30,24) mm, within steel concrete which is filled with No.50 concrete, and through the upper and lower horizontal line, belly bar and horizontal space for stable system composed of diagonals. In the two arch ribs are located 20 meters horizontal stays horizontal line, are steel truss.Figure 2 : General tectonic layout of the main arch ribsThe transportation ability is limited because the bridge is located in complex terrain. The processing of large segments of the overall transport which produced in factory is difficulties. The small unit spare parts could be delivered to the site, while it is also difficult to guarantee on-site welding quality of the main force component. Therefore, rib components node board are used to connect high-strength bolts in the factory processing pre-fight, so the part of arch ribs are made of high-strength bolts connecting node board and the spare parts are delivered to the site, and assembled the resumption of large segments (by ventral pole to form a complete "N" division) in place of assembled platforms, the connection principle is "After the first bolt welding, bolt welding with", meaning tube end set blue plate, using high-strength bolt connection, pipe outer seam penetration welding a circuit. To facilitate the workers, in the main steel tube construction, stepping in the pipe welded reinforced underside are set.Yuancheng Peng, Yiqian Li and Xiaohong Long 169 The main arch rib installation are used of cable crane system, using "two sides symmetrical cantilever, in parallel to the cross in the closure of the cable-stayed hanging Law" construction. Cable crane hoisting system consists of cable and cable-stayed pegged system.The main arch seat using integrated reinforced concrete structure, abutment foundation should be placed in stable. The complete weak weathered bedrock, the required bearing capacity of foundation to allow no less than 2000KPa.2.2 Arch bridge on the column and system structureThe column upper arch using 1.4×1.0 steel box structure, factory sub-processing, on-site sub-hoisting welding. The cover also used steel box beam structure. The whole beam is made in a factory, transport to the site and hoisting to the location. To facilitate the conservation of columns and cap beams, a beam at one end to open a maintenance crossing is built, in the columns and cap beams converge at the capping beam to open a hole on the bottom, and the maintenance workers can easily enter the column inside, the column are equipped with steel escalator up to the bottom.Prestressed concrete are used in continuous box girder, full-bridge horizontal fabric eight small box-girder. The width of precast beam is 2.4m, sit wet joints between the main beam is 65cm. After the in-situ continuous lifting of precast concrete pier top will each piece main beam in the longitudinal bridge to connect, design strength of concrete up to be 90% of post-tensioned pier top steel beam to resist the negative moment. Finally the main beam in-situ joints between the wet concrete, one bridge deck can be formed.The box girder used A class of partially prestressed concrete structure. The middle pier top used double-row bearings, the negative moment area will be adopted the continuous prestressed reinforcement.In order to meet the requirements of anchor layout, the box girder ends was thickening.Figure 3 : General tectonic layout of the main arch ribs2.3 Structure of the junction of PierAbutment pier is located at the junction of the top surface, using double-column 5.0×3.5m. The thickness of wall is 40cm which composed of reinforced concrete thin-walled hollow piers. The junction of piers can be used as a tower platform to meet the requirements to withstand construction loads during the construction.2.4 Welding designThe arch truss, column, cover beams are made of steel, using factory-produced, site assemblage installation methods. According to the load needs and the site of the different environmental conditions, taking into account the relevant norms of the structure of various parts of the weld type and quality, the welding requirements as follows:Longitudinal welded seam and circumferential butt welding are made in factory. Using automatic protective welding process, full penetration type weld quality up to gradeⅠ.170 ARCH’10 – 6th International Conference on Arch Bridges Arch truss, column, cover etc. structural unit or a combination of beam welding, are full-penetration type weld quality achieved Ⅱ.The site installation of welding are basically operated at high altitude. Angle-weld type, U-type multi-layer welding can be non-penetration type weld, so the quality grade is Ⅲ, without flaw, but they must meet "quality standards for visual inspection welds. "3 MAJOR CONSTRUCTION PROGRAMThe cable crane without stents that is typed "WJLQ3000KN" is used to construct the main arch rib in this project. Columns on the arch, steel cap beams and box girders. With the design span of 756 meters, the single-hook lifting weight of 75T and rated total lifting weight of 4×75T=300T; using reinforced concrete gravity anchors during the construction; the main load-bearing cable is "single-Span and double-Cable style" which is combined by 20 ropes with the diameter of 62mm; "spiral friction hoist" and "car running by increasing force" are used as the running and lifting mechanism; the power is provided by four 28T binoculars slow hoists and four 10T monoculars fast hoists; traction speed is 0.36~10m/min, lifting speed is 0.26-3m~min, displacement accuracy is less than 1mm; total design life is 12,500 hours and the working-level is A7.According to the structure of the bridge and the feature of topographic, the cable-stayed hanging system of the main arch rib is a system of conversion and balance of force. It is composed by fulcrum that is the pier(capping beams) at the junction of shore and stiff load transfer beam that is anchor beam on top of pier and abutment. Through the buckle cable, balanced cable, pre-stressed anchor, approach bridge box girder. The cable-stayed hanging system is composed by five parts: buckle point, buckle cable, buckle pier and anchor beam, balance ropes and anchorages, bracing system of buckle pier and anchor beam.In order to reduce the adverse effect that caused by the excessive weld from traditional buckle point on the main structure, setting steel anchor beam under the winding pipe to connect the main arch rib and buckle cable at the buckle point. Steel anchor beam support the arch rib through node plate and make occasional connection between the battens of the arch rib node plate and the bolt.To avoid the local excessive stress, which may cause the bucking at the thin-walled steel pipe and the node plate, main chord steel and node plate at the buckle point of the main structure was partial to strengthen, added 1~4 stiffened plates with 16mm wide and 100mm thick. Added 50mm wide and 16mm thick stiffened ring in the main arch steel at the buckle points of L9、L10、Z4、Z5,which bear larger force. To the cable force is larger than 100t of the buckle cable(L9、L10、Z2、Z4、Z5), set reaction frames at each buckle point. There should be 40 reaction frames in this bridge. The structure type of the reaction frame is public-shaped block welded by plate, the height of the frame is 270mm and the contact surface with the node of arch rib and steel anchor beam is 500×680mm and 200×500mm. The effect of buckle cable is delivering the construction load such as the weight of arch rib during the construction of arch rib to the buckle pier and anchor beam and appropriately adjust the elevation of the main arch rib.Semi-cross-rib is divided into 15 segments to construct, each segment is located buckle cable, the 3rd,6th,9th,12th,15th segment number are followed Z1~Z5; the others are followed L1～L10. Each buckle cable has 4 beams, symmetrical arrangement in the medial or lateral rib. According to the different force in cable, buckle cable is strand, respective choice for the strand, 3φ15.24～18φ15.24.Buckle cable with single-end tension, the tension-side is at anchor beam of the junction pier, fixed end is in the buckle point of the arch rib.Z1 ~ Z5 buckle cable tension side is adjustable anchor named OVM25O, L1 ~ L10 buckle end of cable tension using OVM15 type of common anchor. "P"-type anchor are used in all the fixed end of prestressed steel beams.The cable stress in the L1～L4 is little, to make the force of structure clear and reused steel anchor beams, after the Z1, Z2 fastened, may remove L1 ~ L4 buckle cable, the remaining buckle cable will be removed after the closure of the main arch ribs.Yuancheng Peng, Yiqian Li and Xiaohong Long 171 Cable buckles are the horizontally symmetrical arranged inside the steel pipe of the arch ribs or outside, are away from all the transverse coupling components of the main arch. Angle of vertical buckle cable install: Yichang was 76.132 ° ~ 3.095 °, Enshi was 74.416 ° ~ 0.795 °Table 1 : One exampleBuckle cablenumberL1L2 Z1 L3L4Z2 L5L6Z3L7L8Z4 L9 L10 Z5 Maximum cable force 2125 66 4242105525063707495 110 123 171Yichangnφ15.24 3 3 7 4 410 5578810 12 14 18 Maximum cable force 2025 66 44441105555687681109 125 138 196Enshinφ15.24 3 3 7 4 410 5578810 12 14 184 THE MAIN TECHNICAL CHARACTERISTICS(1) This CSFT deck arch bridge is ranked as the longest one in the world with the main span of 430m;(2) This bridge, across the deep groove Canyon, links with tunnels on two end sides. It is necessary to excavate a small 800m long tunnel to reach the construction site at the Enshi shore. The complex topography and difficult transportation ranks it as the worst construction condition in the world;(3) The topography at two end sides are steep cliffs with no change to set the wind cables. Maximum cantilever length of the main arch cable-stayed hanging is 215m, seldom recorded; (4) The elements of the arch ribs are connected with node plates and high-strength bolts, which are first fabricated and processed in the factory, then delivered to the construction site, and finally assembled on the platform after hoisting of large segments in place, using the method of "bolting first, then welding”, or “combined bolting and welding .REFERENCESChen Baochun, 1997. A summarized Account of Developments in Concrete-filled steel tube arch bridge, Bridge construction, 2(2): p.8-13.Chen Baochun, 2003. State-of-art-theory of calculation for Concrete-filled steel tube arch bridge, China Civil Engineering Journal, 12(36): p.47-57.We Jiangang and Chen Baochun, 2004. Finite element methods for analysis on material nonlinearity of concrete-filled steel tubular arch, Journal of Fuzhou University(Natural Science), 6(32): p.344-348.Xu Yan and Hu Side, 2006. A study on the dynamic ultimate capacity of CFST arch bridge, China Civil Engineering Journal, 9(39): p.66-73.Hu Shide and Su Hong, 2004. Three dimensional elasto-plastic seismic response analysis of CFST bridge, China Journal of Highway and Transport, 1(1): p.57-61.。

前言公路桥梁交通是为国民经济、社会发展和人民生活服务的公共基础设施，是衡量一个国家经济实力和现代化水平的重要标志。

我国从“七五”开始，公路建设进入了高等级公路建设的新阶段，近几年随着公路等级的不断提高，路桥方面知识得到越来越多的应用，同时，各项规范也有了较大的变动，为掌握更多路桥方面知识，我选择了支井河大桥施工图设计这一课题。

本次设计路段位于巴东县野三关镇支井河村. 它是根据设计任务书的要求和《公路桥规》的规定，选定装配式预应力T形截面简支梁桥，该类型的梁桥具有受力均匀、稳定，且对于小跨径单跨不产生负弯矩，施工简单且进度迅速等优点。

设计内容包括拟定桥梁纵,横断面尺寸、上部结构计算，下部结构计算，施工组织管理与运营，施工图绘制,各结构配筋计算，书写计算说明书、编制设计文件这几项任务。

在设计中，桥梁上部结构的计算着重分析了桥梁在施工及使用过程中恒载以及活载的作用力，采用整体的自重荷载集度进行恒载内力的计算。

按照新规范公路I级车道荷载进行布置活载，并进行了梁的配筋计算，估算了钢绞线的各种预应力损失，并进行预应力阶段和使用阶段主梁截面的强度，正应力及主应力的验算。

下部结构采用以钻孔灌注桩为基础的墩柱，并分别对桥墩和桩基础进行了计算和验算。

主要依据《公路钢筋混凝土及预应力混凝土桥涵设计规范》（JTG D062-2004）,《公路桥涵地基与基础设计规范》（JTJ 024-85、,《公路钢筋混凝土及预应力混凝土桥涵设计规范》（简称《预规》）JTG D60—2004《公路桥涵设计通用规范》（简称《通用规范》）在本次设计过程中，新旧规范的交替，电脑制图的操作，都使我的设计工作一度陷入僵局。

在指导老师***老师及本组其他组员的帮助下，才使的这次设计得以顺利完成。

在此，对老师和同学们表示衷心的感谢。

由于公路桥梁工程技术的不断进步，技术标准的不断更新，加之本人能力所限，设计过程中的错误和不足再所难免，敬请各位老师给予批评指正。