Research And Application On Preload Construction And Monitoring Technology Of Large-span Steel Truss

Large-span steel truss as a novel and unique structure form, because of its strength rationality, satisfactory seismic performance, strong stiffness, light weight, speedy construction, ability to meet the requirements of big basement, the economic use of materials, simple structure and environmental protection and many other advantages, is in extensive architect 's good graces, apply in many modern large-scale public buildings. Especially with our social and economic development, spatial structure has been greatly developed in recent years, the span of the transfer floor of building bigger and bigger, construction problems emerging, not only to design an enormous challenge, but the construction will present a new request. At present, domestic and foreign scholars commonly used in engineering a phased conversion layer structure a number of experimental and theoretical study of the structure of the conversion layer force characteristics have a better understanding, some research results have been obtained in engineering practice application. But the lack of conversion of the structure of the various forms of systematic research, especially for long-span steel truss construction technology transfer structure of the application of small, very little relevant literature, can draw no relevant engineering experience. As more and more complex large span steel truss conversion occurs, continue to emerge out of the construction process solved the mechanical and technical problems. To meet the large span steel truss conversion trend, the paper arts center project in Chongqing Cathay background preloading construction method was first proposed, and its depth of research, mainly to complete the following work:①First of all domestic and international transfer story structure on the design and construction of the development, function and form of transfer structure, status, etc. were systematically introduced and summarized, and practical engineering of preloading and prestressing method Comparison, given the options of preloading theapplicability and necessity of the construction.②Details the contents of pre-press and method of construction control. Analysis and comparison of various methods and proposed construction of optimum control of the pre-pressure method.③Construction method for the construction of pre-press process, the basic principle of pre-pressure, pre-press key technology and construction difficulties, the imp ortance of structural analysis, finite element modeling of the prerequisites and ANSYS modeling and calculation methods A detailed description of the modeling by ANSYS analysis, the truss under load in the upper mid-span deflection and the stress component changes, pre-press for the truss truss design and evaluation of bagging provides a theoretical basis.④Focuses on the construction method of preloading the specific implementation. Include: making and installing steel truss hoisting, hanging baskets and hanging point for the design, grading and unloading systems, loading materials, construction monitoring and security measures.⑤Main line construction monitoring, with emphasis on the pre-construction monitoring pressure of the purpose and requirements, contents and principles of surveillance, monitoring the process and the test point arrangement, and monitoring results and finite element results were compared, demonstrated Finite element modeling and analysis is reasonable, further demonstrated the importance of information construction.