Error-theory Analysis For Closing Technique In Long-span Steel Truss Bridge

Since the fifties of the 20th century, with the development of transportation, the demands of bridge is increasingly urgent in our country. Meanwhile, the country has not only increased investment in transportation facilities, but also learnt the advanced bridge design skills from the other countries through the technology exchange. In the fields of steel, manufacturing technology and construction technology, China has been equipped with the ability to construct the large span steel truss bridge. However, the study of steel bridge started relatively late in our country. Thus, many theories are still in development stage, especially theories of the steel truss bridge, such as how to ensure the closure in high-precision. The main works of this paper are:1. Through the establishment of related coordinate system, the calculation equation can be derived, which is fit for the installation in the engineering and manufacturing error, providing the accumulation error of the two cantilever-side of Dongjiang bridge.2. Analysis of the impact on linear displacement and angular displacement caused by translation errors, rotation errors, and manufacturing errors.3. Indication of the type of truss that should be paid more attention in the installation process.4. Analysis of the construction practice of Dongjiang Bridge, determining the pole of the assembly sequence; beginning with the assembly sequence to ensure pole error that is included line displacement error, angular displacement error and manufacture error.5. Through the calculation of errors of Dongjiang Bridge's installation and manufacture, analyzing the results to determine the vertical bridge system and the accumulation of significant influence on the error bars.6. Calculating the total value of linear displacement error, angular displacement and manufacture error. The source of error is the angular displacement error, so it should be paid more attention during the construction monitoring.7. Comparing the theoretical value with the data which are collected on site, and analyzing the cause of the error in order to conclude comparatively secure theoretical calculation which is adaptable to actual engineering.