The design principle, installation and test of a passive automatic cable releasing device were described. It is based on horizontal retractable technology and used for releasing main cable strand of suspension bridge. The release quality of main cable strand was greatly improved after the adoption of the device.
Based on the technology research of homemade 1 770 MPa main cable strand of Xihoumen Bridge, the paper further researched the manufacturing technology of main cable strand with super length (≥4 250 m), big specification (≥169 spec.) and high strength (1 860 MPa grade) and the technique and device for setting cable or receiving cable of the level packing in coiler. It provided a technique research foundation for main cable strand of super long span suspension bridge.
The transport technology of coiled main cable strands with super length and large size was introduced in this paper on the basis of two examples.One is the main cable strands transport of Xihoumen Bridge which is a steel structure suspension bridge with the span of 1 650 m; the other is the main cable strand with the size of Ø5 ×169 wire ×4 250 m and the weight of 120 t.
The processing equipment of main cable strand with super length, large size and high strength was described in this paper. It provided reliable industrial equipment for the manufacturer of suspension bridge and satisfied the requirements of large-scale production.
In order to study the influence of central buckle in suspension bridge on different suspension systems, this paper took Xihoumen suspension bridge as an example, established its finite element model with main cable span of (578+1 650+465) m by using bridge nonlinear analysis system BNLAS, which was developed by Southwest Jiaotong University. Then, it analyzed the influence of central buckle on suspension bridge's structural performance with different supporting forms.
In the investigation of rock mass's deep joints and fissures' grown feature in Xihoumen Bridge northern tower, some integrated survey technologies like drilling, view in bore, CT, packer permeability test and so on were adopted,which offered the detailed and exact base of Xihoumen Bridge's designing and building, as well as a golden experience for the groundsill basis in major works in future.
In order to study the influence of tower stiffness on suspension bridge, this paper took Xihoumen Suspension Bridge as a prototype, established its finite element model by using BNLAS (Bridge Nonlinear Analysis System), which was developed by Southwest Jiaotong University. This model is a two-mtower single-mspan suspension bridge with the main cable span of 1 650 m, and it has single-mspan simply supported girder. Then, the influence of suspension bridge structural performance with different tower stiffness was analyzed by changing the model's tower stiffness (0.7, 0.8, 0.9, 1.0, 1.1, 1.2 and 1.3 times of original tower stiffness). This paper also discussed the influence of mid-mtower stiffness in multi-mtower and multi-mspan suspension bridge.
Because the thickness of orthotropic steel deck is thin and the stiffness of pavement is relatively large, the interaction between orthotropic steel deck and pavement on it can not be neglected in the fatigue design of orthotropic steel deck. Based on the assumption of non-slip between pavement and the bridge deck, influences of elastic modulus and thickness of pavement on the fatigue stress range of four typical details in orthotropic steel deck were discussed according to FEM(finite element method) analysis results.
Horizontal preframe method was adopted when steel stiffening girders of Xihoumen Bridge were fabricated, i.e. the steel box girders were pre-assembled in horizontal direction. To insure the vertical line figure of girder segments is right, relevant parameters should be calculated and stimulated first according to design data, then every part of the steel box should be adjusted in preframe process, and finally the linear accuracy should be checked.
Xihoumen Bridge is the longest two-span continuous steel box girder suspension bridge in China. Several problems have been encountered due to severe natural environment during the erection of steel box girder at anchor-side of north side span of the bridge. The key technique and construction process of erection and linetype adjustment for the steel box girder are introduced.
In order to solve the long-term corrosion problem for large-scale steel box girder bridges, this paper relies on Zhejiang Zhoushan Xihoumen Bridge, combining with arc spraying anti-corrosive coating technology and nano-modified sealing coating, the arc spraying nano sealing composite coating system was designed, comparing the conventional arc spraying composite coating system and innovative design solutions of arc spraying nano sealing composite coating system. Different arc spraying metal coating materials were recommended for different corrosive environments. The technical parameter comparison of nano sealer and common anti-corrosion epoxy primer were analyzed comparatively. Quality requirements and testing methods of arc spraying nano sealing composite coating system coating procedure arc briefly introduced.
Risk analysis and quantitative management concepts are applied to the overall design of electronic bridge inspection and maintenance management system to customize the inspection and maintenance strategy and standardize bridge inspection process. Also the inspection and maintenance manual is composed to guide the bridge management. The electronic inspection and maintenance management system is realized by developing the software, structural database and particular defect knowledge database.
The paper states the methodology of SRA (structural risk analysis)of Bridges. In terms of the objects of SRA, the contents and approaches of sea crossing suspension bridge SRA are defined. The risks to be controlled necessarily are concluded by the global risk analysis, and how to achieve the control is worked out by the element risk analysis. Meanwhile, the risks of the external special events and special maintenance are included in the SRA to make sure that all risks are analyzed and controlled and none of risks in the bridge life-cycle is ignored.
Based on structural risk analysis methodology and quantitative management theory, the inspection and maintenance management of trans-oceanic suspension bridge is broken down to sub procedures on the element level. The risk management of the bridges is realized by defining all contents of the inspection and maintenance strategies of every kind of element including the management of the special external events and special heavy maintenances. Also the components of management system were introduced in the paper.
Some problems existing in saddle pushing, such as the pre-displacement control principle, the relation of tower top displacement and tower bottom stress, the method of determining saddle pushing stages and pushing values, are discussed. The reasonable model of saddle equilibrium condition and the pre-displacement calculation method are expounded. Combining with saddle pushing analysis of Baling River Bridge, the conclusion that the excess pushing scheme can increase the interval of each pushing and reduce pushing times is obtained. The cases following saddle pushing are the unfavorable conditions for main cables anti-sliding checking.
Intelligent maintenance management system of Xihoumen trans-oceanic bridge was introduced, including subsystems and functional analysis. Integration solutions of intelligent maintenance management system were proposed, and the software realization and web integration technology for the system integration were put forward.
Because it is difficult to accurately determine the effective length and bending rigidity of a hanger, the tension calculation of short hangers according to formula method may lead to big error. Taking the testing of hanger tension of the Xingou River Bridge as the research background, the effects of such parameters as boundary conditions, bending stiffness, effective length and linear density on the accuracy of the tension measurements are analyzed in detail. The results show that the simplifying assumptions of formula method are not suitable for short hangers. Hanger tension calculation with finite element method is introduced. The finite element model is established according to real condition. Firstly, the bending stiffness of hangers is identified; then corresponding relationship table of hanger tension-frequency should be established. The corresponding tension of a measured frequency can be obtained through looking up the table. The method has been applied to construction monitoring of Xingou River Bridge and proved to be an effective method.
With the development of health monitoring system for the long span bridge, how to use the data effectively to give proper assessment is of vital importance in the field of the world bridge engineering. Based on the investigation of present assessment methods, through the experiences of practice engineering—Zhoushan Island Xihoumen and Jintang Bridges' health monitoring system, the authors designed a new assessment system, making comprehensive assessment of long span bridges, combining cutting-edge theory and practice, and striving to provide a scientific basis for maintenance and management.
Taking Zhoushan Mainland-Islands Link Project as an example, the importance and research status quo of health monitoring study of trans-oceanic bridges were discussed. Then, the key techniques and study direction were analyzed, and the study idea of structural damage identification considering nonlinear effect and load feature were presented to improve bridge damage evaluation ability by a comprehensive health monitoring system.
General design principles of bridge structural monitoring system are studied through Xihoumen Bridge structural monitoring system. And the design methods and basic functions of the sensors, data acquisition and transmission, data management and safety evaluation subsystems are illustrated.
The structural monitoring system for Xihoumen Bridge is designed and implemented by employing the design method proposed in the paper of Design and Implementation of Structural Monitoring Systems for Xihoumen Bridge (I): Design Method. The general design framework, the design method and implementation of subsystems are examined. The loads and responses of the bridge are analyzed when the structural monitoring system is running and collecting data. The results indicate the structural monitoring system for Xihoumen Bridge is running normally and achieves the desired objectives. The distributed data acquisition and transmission system based on industrial Ethernet is applied and developed well in the bridge structural monitoring system, and can be popularized.
Basic functions and constitution of bridge structure health monitoring software were discussed. The application of ArcObjects was reviewed, and key technologies and characteristics of the software were pointed out.
Aiming at the low flexibility of data analysis and high rate of data errors of traditional data reporting program, this article transformed the problems into multiple templates report, proposed a RDL-based data reporting program. Engineering application results show that the program has the advantage of high flexibility, high degree of integration and high operability, therefore, the program can effectively analyze the data of bridge structural health monitoring system.