The paper analyzes current state of innovation system in the field of public infrastructure construction in China, elaborates on the duty and role of the owner in establishment of a technical innovation system with enterprise as main body following the process of production-education-research. This paper also claims that key project construction is an important resource to enhance national capability of innovation and accordingly puts forward an effective approach to cultivate the core competitiveness of leading enterprises on the basis of practice in Sutong Bridge.
This article presents the justification and decision-making of the project plan during the initial stage for Sutong Bridge, with emphasis on initial stage for Sutong Bridge with respect to the justification of location of Sutong Bridge, comparison and selection of project plan for the river-crossing main bridge and studies on special research subjects.
In this paper, design and construction concepts are briefly presented. Furthermore, key technologies and innovative achievements are summarized mainly on piled foundation bearing capacity analysis, river bed scour protection and monitoring, superstructure wind-resistance study, mid-span closure method as well as long cantilever structure construction control.
Sutong Bridege, whose layout is ( 100 + 100 + 300 ) + 1 088 + ( 300 +100 + 100 ) m, marks the largest span of cable-stayed bridges in the world. The complex natural condition at thr bridge site and the strict requirements for resistance of wind and seismic action make it crucial to choose a favorable structural system to addure the funcrion and safety of the bridge. The comparsion among several optional structural systems for Sutong Bridge is illustrated, the optional structural systems contain floating, viscous damper, hydraulic buffer, and fixed system. After detailed analysis is carried out for viscous damper and hydraulic buffer, super liquid viscous damper with additional displacement limitation is designed for the first application in bridge engineering. The parameters for the damper is analyzed and studied and the dampers are installed sucessfully after required damper tests.
The cable force experiment was carried out during the design of Sutong Bridge. By comparing with the international research results, the calculation formula of longitudinal wind drag coefficient for cables was advanced to fill the blank of bridge wind resistant code of China, and this formula has already been adopted in the Highway Bridge Wind Resistant Design Code (JTG/T D60012004) with great significance for bridge engineering.
Aerodynamic problems of super long span cable-stayed bridge are investigated based on Sutong Bridge.Dynamic properies, wind loading, identification of flutter derivatives based on full aeroelastic bridge model, logitudinal structural system and vortex excited vibration are mainly focused on. Researches show that vertical stiffiness will decrease with wind speed if the nonlinearity of deformation of stay cables under later wind loading is considered. It is also found that Fixed - Fixed system is the most suitable for long span cable stayed bridge under logitudinal wind loading. Identification method of flutter derivatives through full aeroelastic bridge model is proposed. In the end, some discussions on vortex excited vibration and Rehnilds number effect are intoduced.
This paper, from three aspects including construction conditions, foundation design and construction, introduces some considerations in the designing of main-pylon foundations and some practical measures to deal with certain unfavorable construction conditions, such as deep water, tidal effect, soft stratum and heavy traffic, during the construction of main-pylon foundations.
Starting from structural description of deep-water group pile foundation, the paper analyzed impact to the bridge safety introduced by scour and its protection and further presentsed different solutions of scour protection for foundation structures of the bridge.
Sutong Bridge tower with 300.4 m is the highest one in the world, The tower anchor area uses the steel-concrete composite structure; its structure and the stress mechanism are complex, so it must be paid more attention to the structure durable issue. The 300 m height makes the tower quite sensitive to the environmental factors such as wind and temperature. The wind-resistance safety of tower in construction stage against the wind is important especially. In this paper, the design of composite structure is introduced. The key technologies of tower geometry control and wind resistance in construction stage are analyzed.
This paper focuses on introducing the manufacture technique of the 1 770 MPa galvanized steel wire for stay cable usde in domestic bridges. During the development practices of high strength galvanized wire for the stay cable of Sutong Bridge, Baosteel Group established three key tecchnologies based on the research of manufacture technique and technological innovation. The three key technologies based on the research are: "Double tension + limiter die" process technology, "primary process + fine tuning" initegrated optimization technology and "three-level control" hot galvanization operation technology. With these key technologies, Baosteel Group produced the 1 770 MPa galvanized wire used for stay cable, which has high strength, low relaxation and good torsion performances.
Sutong Bridge is a cable stayed bridge with a steel box girder and a main span of 1 088 m. The steel box girder of main-span includes five portions: back span large unit, large block of pylon, standard girder, back span closure girder and middle span closure girder. Each back span large unit was fabricated by welding several deck segments together in factory, and was erected by floating crane. Due to the high of navigational clearance of the main bridge, the traditional truss lifting device couldn't satisfy the requirement of domestic lifting cranes for this kind of lifting height and weight. Hence, a kind of lighter lifting device for the erection of back span large units was accepted for this bridge. In this paper, the design and use of this lifting device is introduced.The upper structure used lifting gantry to install the standard girder segment by cantilever method. Because the bridge's navigation clearance is high, and the girder segment is wide and heavy, the meteorology and hydrology condition of the bridge district is abominable, and the requirements of long cable girder side pull-in, structure and performance propose high request to the lifting gantry. In this paper, key points of designing and using long cable pull-in angle adjustment device integrate into lifting gantry are introduced.
In the background of the construction of Sutong Yangtze River Bridge (short as Sutong Bridge), the cable construction method and techniques of a thousand-meter scale cable-stayed bridge are instroduced, Some key constrction techniques, such as outspreading cable on deck, installing cable at pylon, pulling adn fixing cable at the attachment with decks and cable PE protection, are discussed.
By abstracting the advantage of the pullback method abroad and the deomestric temperature-cutting method, a new assistant pullback method is put forward and brought into practice actually. In this paper, the analysis key point of practice conditions, key parameter of practice, main measures of the method and the performance are introduced.
According to construction and load action on SuTong Yangtze River Highway Bridge, an analysis model for structural stability was studied and solved through FEM. Stability safety factor and mode were obtained, and some problems on stability for the installation of steel box girders were also discussed.
Sutong Yangtze Highway Bridge is the longest span cable-stayed bridge completed in the world nowadays. The construction of superstructure of the main bridge was composed of several stages including erection of big block girders for side span, assistant span and tower area, erection of standard girders and middle span closure. The big block girders were hoisted as integer by floating crane. The standard girders were hoisted by double cranes system at the deck. Pushing assistant method was adopted in middle span closure construction.An all-stage self adaptive geometry control method was used in the construction process. By all-step accurately control to unstressed dimension and shape of all structure components and realization that control system and controlled system adapt to each other, the goal to make the final line shape and inner force of bridge structure under control could be achieved. Two solutions including based GPS and based total station dynamic geometry monitoring systems were used to resolve the measure problem under the condition that wide–range wind-induced vibration with long cantilever state. Finally, the research on wind-induced vibration of super structure during the construction period was executed. Buffeting response analysis to the longest single and double cantilever state were carried out. The analysis and evaluation to wind resistant safety of main girder at the longest single cantilever state were made, and the corresponding wind resistant measures were suggested. As built geometry error and cable force error were controlled in a range design required.
To keep up with the time, culture is integrated to large-scale construction project management in China, which will absolutely add more vitality into construction project management in our country. Engineering culture is an integration of project construction and engineering culture. However, engineering culture development enjoys its own particularity as a project is constructed once only within a limited period of time. This paper gives affirmative opinion that engineering culture development in large-scale projects backs project management on the basis of thorough investigation of engineering culture development in Sutong Bridge project and after deepened analysis, proposes new thinking pattern of engineering culture development in large-scale projects in a systematic manner, including thorough understanding of the essence of engineering culture, principle and contents of engineering culture development as well as efficient method in respect of establishment and implementation of engineering culture, and therefore provides a standard reference and systematic thinking pattern for engineering culture development in future large-scale projects.
This Issue
Mar 2009, Volume 11 Issue 3