Construction Technology Research And Monitoring Of Large Span Steel Structure

Considering whether space steel arch and lower reticulated shells work together in the process of tension, two kinds of construction programs about suspen-dome with stacked arch structure is made. Based on those programs, analyses of the whole construction process are conducted about the entire structure and cable force, member forces and structural deformation in the period of tension. Construction monitoring was done in order to guarantee the construction carrying on smoothly. Monitor results verify the theoretical results well and prove the feasibility of the construction simulation by finite element software.Research and mechanical simulation on key technical problems and in construction process of large span overhanging structure was done. Design principles of temporary supporting and unloading plan for this program was determined focusing on the its characteristics. Numerical simulation of temporary supporting was done by equivalent displacement method. Optimal way for casting concrete of suspension floor was determined by comparison and selection of different schemes and numerical calculation, which guaranteed the construction going on smoothly.Aiming at key problems in the period of construction of a complex steel structure system which combines steel frame-supporting system and intersected trusses, deformation control measures in construction and uninstall of the whole structure are simulated by the finite element. Meanwhile changes of strength and stiffness of the structure in loads conversion process are studied. All of those analyses can provide theoretical support to the determination of construction programs and can ensure the construction process running on smoothly. Three methods, electric resistance static strain testing system, electric resistance dynamic strain testing system and vibrating wire strain gauge system were used for monitoring. The stress of key joints of Tianjin library which combines steel frame-supporting system and intersected trusses is monitored in the whole constructing process. Results of these 3 ways are in accordance with each other, which guaranteed the smoothness of construction procedure and the accuracy and validity of monitoring results.Radial spherical plain bearing is brought into the cable-member systems of Suspended-dome as the rigid rotational core of strut up-joint, which forms the radial spherical plain cable-member system alongside the non-sliding cable strut joint. Full Scale axial loading tests as well as FEM calculation were carried out. Analysis method based on non-linear FEM is proposed. The tensioning process of cable dome with radial spherical plain cable-member system was analysed, its lofting state was also determined. Construction monitoring of tensioning process was carried out. Displacement of upper structure and bearing as well as the pre-tress of cables were monitored, which not only guaranteed the safety and reliability of structure but verified the numerical simulation method of tensioning process.Research on the general idea and key points in actual process of sliding construction method for cutting and lengthening long span structure was done. By the study of strengthening web members, erection of supporting frame, designation of pushing point and synchronization controlling etc., the program carried successfully.In this paper, arrangement of measuring points about mentioned different forms of large span steel structure is determined by mechanical characteristics, structure arrangement working conditions on site and so on. Meanwhile those measuring points are laid in the principle of striving to achieve “integrity monitoring, taking both stable performance and excellent value for money into consideration”. All of those studies can provide a reference for future related projects on construction monitoring.