Investigation On Design And Construction Technique Of The 450m-Span Spactial Steel Latticed Structure With Giant Grid Size

The earth is we human beings known as the "mother", it is the survival of our homes. So far, in the human science and technology can detect the planet, the earth is the most suitable for human survival. But with the development of human civilization, especially after the industrial revolution, with the wanton destruction of human on the environment, and free pollution, the earth’s ecological environment has become very fragile.The greenhouse effect, ozone depletion, land degradation and desertification, waste material pollution and transfer, forest area reducing, biodiversity reduction, water resources depletion, nuclear pollution, Marine pollution and noise pollution. Predictably, these ecological environmental problems if left unchecked is not solved, the earth will no longer suitable for human survival. When humans continue to stay on earth, whether other planets or immigration, all need to face the severe test environment. At this time, a can provide work for the human living environment, living, entertainment, and be able to withstand the extreme environment of large span space structure is extremely important.The sports park for the span 450 m, at home and abroad about the large span spatial structure especially above 400 m, there is few research, some even only stay on the stage. Other construction process of large span structure research is currently in an early stage, the current research on this aspect also not system, not specific, yet a complete set of construction methods to draw upon. We are always faced with a need to be further solved the problem, how about its construction process through computer simulation, with scientific analysis and adopting reasonable construction scheme, to ensure the construction safety, reduce construction cost. For large span space structures (based on the giant spherical grid structure as an example) type selection design analysis and the corresponding construction methods to explore and study is very proactive.This paper draws on achievements of rectangular grid structure at home and abroad, its applications in large span space structure are studied, this paper mainly analyses the following content:(1)the application structure analysis software Midas/GEN, about 450 m span spherical giant grid structure design, it is concluded that the stiffness and strength characteristics of the structure, mode and stability characteristics.(2) Summarizing the common construction method at the same time, the selected by jack-up method as the construction method of the structure, the method is in climbing dome construction method and inverse do installation method, on the basis of the structure of the integrally jack-up technology and assembly technology, first ring structure around the center structure and in situ assembled on the ground, the center structure jack-up, high-altitude swallow the center link between structure and circular structure, successive center structure construction from within(3) A summary of the commonly used method is selected by jack-up method as the structure of the construction method of determine the jack-up process; at the same time, check the structure in the construction process of jack-up reaction, structure displacement and member internal force; Also in the process of the construction temperature factors are analyzed; Second is still in the process of the construction of the structure of the construction of preset values are calculated, finally through the choice of jack-up method and the design of jack-up stents, solved in the process of the jack-up horizontal force is too large.Summarizes the full text, get the following conclusion(1)Member of the structure and adopts Q420 steel, cast steel node bar for pipe and cross section type up to 15, and the smallest cross section is 351 ×16, one of the largest section of 1200 x42. Through the static calculations of the structure under constant load and live load, wind load and temperature load combination condition of bearing capacity, the use of modal decomposition response spectrum method calculating the structure under the action of earthquake resistance in 9 degrees of bearing capacity and seismic response. Experience to calculate the structure under normal use limit state of flexible cross ratio of 1/1333, meet the specification requirements; While all the bars in the structural composite stress ratio is less than 0.95, satisfy the current specification requirements for strength and stability of the bar, overall bar stress uniform distribution of symmetry; By the statistics, the total capacity of 63000 tons of steel structure, with an area of computing capacity of 314 kg per square meter of steel. Experience is in the process of the construction structure bar stress ratio of 0.98 is less than 1, the top of the largest structure in the process of flexible cross ratio of 1/3429, meet the specification requirements, results show that the jack-up method by construction safety. To sum up, in the construction of taiyuan area 450 m span rectangular grid structure is safe and reasonable.(2) Calculation results of a variety of internal force and deformation during the construction of preset value research, verified the new type of climbing method in the structure the feasibility and safety in the process of construction.(3) Through the choice of jack-up method and the design of jack-up bracket, the top of structure in the process of horizontal force to the bottom of the bracket, again by pushing jack to foundation pit, well solve the problem of horizontal force in the process of the jack-up, once again proved the feasibility of jack-up method step by step.