Taizhou Bridge, locating at the middle of Jiangsu Province, connecting Taizhou and Zhenjiang, started to construct in Dec. 2007. The bridge is the first kilometer level three span suspension bridge in the world. The middle tower of the bridge adopts longitudinal shape of herringbone fashion for the first time in the world. The foundation of the middle tower is the deepest caisson in the earth under water. A great many of technical innovations are carried out to construct the great engineering project, such as the design techniques of the three-tower suspension bridge, the precise locating and bottom-sealing technique of the super scale caisson foundation, the manufacture, connection techniques of steel and concrete in the middle tower, the welding of extra thick steel plate and manufacturing and control of abnormal sections of the middle tower.
Taizhou Bridge is a highway triple-tower and double-span bridge with span arrangement of 1 080 m+1 080 m, the middle tower is located in the center of Yangtze River. Several proposals are studied for the foundation type of the middle tower, especially the comparison between caisson foundation and bored pile foundation with higher pile cape. The caisson foundation is adopted because of its concise structural behavior, larger rigidity and simpler construction procedure, and it's far more economic. According to the configuration requirement of the first section and the structural force, the cross-section of the adopted rectangle caisson's dimension is 58 m×44 m with four circle chambers at corners, the total depth of the caisson is 76 m. The bottom segment of the caisson adopts concrete caisson with steel hull, and its upper segment adopts reinforced concrete structure. The structural arrangement, construction method, comparison of the project's proposal and the design feature are introduced in the paper. The design of the caisson foundation will provided good experience for the future similar projects.
Taizhou Changjiang River Highway Bridge is a suspension bridge with three towers, two spans and two anchorages. The main span is 2×1 080 m. The south and north foundation of the anchorages are deep water caisson with rectangular plane size 67.9 m×52.0 m. A great many of technical innovations are adopted to solve many technical problems including the disposal of the compound basement, manufacturing and installation of the caisson, fulfillment of concrete in the caisson etc, based on the conditions such as the thick overburden layer at the top of the caisson, the super dimension and the big sinking depth of the caisson. This article gives a brief introduction on construction technologies in huge caisson on the ground and can be taken as a reference during the construction of the super scale caisson on the ground in the future.
It was discussed the proper choice for processing and welding technology of large thin-wall steel caisson in Taizhou Bridge. According to the caisson's characteristics of large size and thin wall, reasonable welding and assembly methods were adopted to effectively control precision in the processes of fabricating and assembling pieces of each unit and the whole caisson, and the welding and anti-deformation precision of thin-wall steel sheet can be controlled too. Thus the processing quality was guaranteed.
The dimension of the north anchorage of Taizhou Bridge is 67.9 m long, 52 m wide and 57 m high. The water dredging method was adopted at the beginning of the sinking process. The cost of water dredging method is lower than the un drained dredging method and the efficiency is much higher and more controllable. This method can form good sinking direction to assure the sinking velocity and preciseness, especially suitable for the geological condition of clay and clayey. This paper introduced the water dredging construction method of the super scale caisson based on the north anchorage of Taizhou Bridge.
This article described the successful experience of using steel sheet pile cofferdam on building island as pile installation platform. Constructing steel pile cofferdam in advance on cap construction instead of steel platform can reduce construction cost, schedule and construction difficulty, and improve construction quality.
The left branch bridge of Yangtze River's branching channel in Taizhou Bridge project is a 5-span continuous beam bridge with the layout of 87.5m+3×125 m+87.5 m. The diameter of bored piles is 2.0 m, and the length is 94 m. All the piles are constructed by rotary drilling rig. Based on the construction of the bridge, the paper analyses the construction techniques of rotary drilling rig, details the drilling mud, drilling rig's installation, drilling, and summarizes the features and experience, proposing reference for similar project in the future.
The total stiffness of a three-pylon suspension bridge is relatively small. The middle pylon structure of a three-pylon suspension bridge has great influence on the mechanical behavior of the whole bridge. The contradiction between the slip factor of main cable on the top of pylon and the ratios of the deflection to span of the bridge needs to be solved. Based on the analysis of the characteristics and structural behavior of middle pylon of Taizhou Bridge, structure selection of the pylon is done and longitudinal herringbone steel pylon is taken. The structure design of steel pylon and process with key structures, which include weld design for thick plates, structure dispose of branching nodes, connection type between the bottom of steel pylon and concrete bearing platform are introduced. The longitudinal blocking partition design based on crane capacity is also introduced.
The central tower of Taizhou Bridge adopts the vertical steel tower structure for the first time in the world and its manufacturing and installation are also difficult. Through targeted analysis in the steel-concrete composite section, the integral segment, the lower link segment and different structural forms of the steel tower, we propose different manufacturing programs for different segments, and the application to Taizhou Bridge will provide references and technical support for using high-strength steel plate and manufacturing of the steel tower with complex structural forms.
In this paper, we researched the key technology of the level pre-assembly of Taizhou Bridge steel tower, proposed the principle of the pre-assembly process in the complex structure steel tower. After studying the environment effect, supporting conditions and the metal contact rate measures, we solved the problem of the control points in process. Level pre-assembly of steel tower fills the technology gaps in China and provides a strong basis for the follow-up complex steel tower pre-assembled program.
Taizhou Bridge is a three-tower, two-span suspension bridge with the herringbone middle tower in the longitudinal direction. The two oblique legs are anchored by screw bolts at the top of the concrete cap and the pressure plates of the D0 segment transmit pressure to the concrete cap. The top surface of concrete has bi-directional slope degrees. The space needed for concrete cement paste jacking is reserved at the top of the tower cap. After the segment D0 is installed, the concrete mud with high strength and no shrinkage is pressed into the space to form the supporting surface of the pressure plates. This paper briefly describes the concrete cement paste jacking techniques used in the construction procedure.
Taizhou Changjiang River Highway Bridge adopts a three-tower, two-span layout for the first time in the world. The longitudinal shape of the middle tower is herringbone, and the steel gallows frame is adopted in the cross direction. This paper describes the installation, locating, and adjusting construction techniques of the huge segments including the selection of hoisting equipment.
Taizhou Bridge is the first kilometer level three-pylon two-span suspension bridge. The middle tower is manufactured by steel with little practical engineering experience. The design and construction of cat walk system is critical to the installation of the superstructures. The design of cat walk system of Taizhou Bridge chosen the continuous four-span structure without anti-wind cables based on the analysis of critical problems of the three-pylon two-span suspension bridge. This paper describes details and construction sequences of the overall design of the cat walk system and the supporting cables, arm rest cable, anchorage system, surface cover, and cross passages, which can be used as references in the similar engineering projects in the near future.
Aiming at the structure features and construction methods for the south anchor caisson foundation of Taizhou Yangtze Highway Bridge, this paper presents a design scheme of security monitoring in construction. The result from monitoring data in construction shows that the horizontal tension stress which near blade foot at the bottom of well are greater in initial well sinking. It will effectively guide the well construction with the physical quantity as the control index of well sinking. Sidewall earth pressure increases first, and then decreases with the increase of embedment depth.
The risk of ship collision to the center tower located at the edge of navigation channel of Taizhou Yangtse River Highway Bridge is expected. To protect the bridge, this research integrates a variety of factors to study the protection system of the center tower. Aiming at the suspension bridge with three-tower-span, with combination of ship navigation planning, bridge parameters and characteristics of bridge foundation, the ship collision research is carried out and protective measure scheme is proposed. Calculation and analysis for crash characteristics are carried out to determine the technical and economic characteristics of the protective measures. The safety of the bridge and effectiveness of the protection system under ship collision is studied by applying the dynamic FEM techniques.
Since 1980's, a lot of long-span prestressed concrete continuous system bridges have been constructed in China, and great success has been achieved. However, with the increase of numbers and service life of bridges, some similar diseases have been showed in this kind of bridges in succession. In this paper, the forms of many typical faults like excessive deflection in the mid-span, box beam crack and bottom slab stripping in the closure segment of mid-span, etc., have been summarized. And the characteristics of these faults' happening time, trend of development and distribution form have been pointed out. Their causes and corresponding prevention countermeasures have been analyzed. At last the direction which needs further study about the theory of computation and the measures which should be taken in design have been figured out .
The tooth plate anchorage zones of the prestressed concrete girder bridge bear the anchorage forces and radial forces of prestressed bars and are easy to form cracks or break due to discontinuities in geometry. So the designs of anti-crack bars are critically important. Seven classical tension stress distributions are described in this paper and a model based on strut-and-tie bar theory is constructed to form a novel design method for the prestressed bar design in the anchorage plates.
The general situation of Taizhou Jiajiang Bridge project and the purpose of the test on Jiajiang Bridge movable-bed model were briefly depicted in the paper. The river hydrological characteristics and the river regime were analyzed to determine the design parameters of the model in this experiment, and the impact of the bridge on the riverway, river bank protection, and river beds was studied, for engineering design and providing a basis for follow-up implementation.
The paper summarized and evaluated asphalt mixture anti-shear test method, anti-shear mechanism and the anti-shear design reasearch recently. The analysis and evaluation of 9 test methods is helpful for related personnel to choose these test methods appropriately. The properties of asphalt grout, anti-shear strength between asphalt and aggregate interface, and interlocking of aggregates, jointly decide HMA (hot mix asphalt) anti-shear strength and are the orientation to improve HMA anti-shear properties. Further researches are needed before anti-shear design is used in engineering to solve the problems such as the determination of relevant coefficient in tolerable shear stress test method and calibration of rutting prediction models based on HMA anti-shear behaviors.
This paper describes the latest progress of main cable dehumidification system key technology, including the dry air dehumidification system design parameters research, the main cable over-pressure exhaust system research, dehumidifiers energy-saving research, and S-type wire localization research, etc.
Take construction station of north tower and north anchor of Taizhou Bridge for example, the environmental impact of solar energy utilization compared to the ordinary coal-fired boiler was analyzed from the aspects such as dust, sulfur dioxide emissions and energy consumption. The results show that the solar energy utilization can improve the camp environment significantly.
According to compilation of Quality Inspection and Evaluation Standards Exclusive Use for Taizhou ChangJiang Highway Bridge, this article introduced some main issues of compilation,and proposed some understanding and appreciation of these issues, providing much useful experience to the same kind standards.
This paper presented the research and development of an information management system for Taizhou Bridge. The system adopted a full-coordinate structure to manage all the applications for the multi-objectives,multi-structures, and multis and solution strategy are discussed in the paper.