Investigation On The Design And Construction Technique Of The 300M-Span Spatial Steel Latticed Structure With Giant Grid Size

Global warming, sandstorm and haze occurred in east China area, deteriorate human living space, which are seriously influence people’s normal life and work. The new city dome style concept is putting part of the buildings or community with completely facilities under the super large span dome, relying on the dome structure to resist the bad natural environment, and depending on the various equipments to adjust temperature and humidity, forming a comfortable environment for human living and working. So, urban ecological dome should be an enclosure space structure. This article based on the existing form and construction research achievement of large span space structure, at 300m spherical three-dimensional truss giant grid structure as the main research object, studying the feasibility on structure selection, the static performance,construction scheme and technique and construction process simulation.Giant grid structure includes the major structure and the minor structure. The main body constituting radial and ring three-dimensional truss is the main force part; substructure is flat truss for secondary stress part. When analyze static performance of the structure using two methods:One considers the major structure bearing force lonely and another considers the major part and minor part synergy carries. Compared the two kinds of calculation methods’ results of structural natural vibration modal, force, node displacement and stress in the bar. At the same time, this paper summarized the existing spatial structure’s construction methods and puts forward in a new kind of construction method to the model in this paper-grading jacking construction method. This method is based on Pantadome construction method and inverse installation method, combining integrally jack-up technology and assembly technology. Firstly, assemble ring structure and the center structure prototype on ground; then jacking center structure; thirdly, replenish surplus bar in the sky; lastly hoist minor parts in place, constructing from center to outer successively. Compared with Patadome menthod, this method does not need to set the uniaxial hinge in structure and not formed an active institution, but can assemble most elements on the ground. According to the simulation analysis results in the construction process, judge jack’s jack-up position and number. Reference the result of simulation analysis, this paper considered the temperature function, recorded transformation and the maximum stress of components for each phase, estimate to optimal construction period and given some appropriate methods to ensure the safety of the construction process when unable to avoid the worst construction season. In addition, calculated the transformation presetting value and analysis lifting jacks trestleThe analysis results show that the method only considering the major structure can basically reflect the whole structure’s static performance, but needed to strengthen upper chords of rack truss connecting with stereoscopic truss. Grading jacking method construction method was suitable for the model in this paper; the rising temperature has a great influence on the construction process. It’s better to avoid the hot summer season to constructe and choose the lowest temperature in summer if unable to avoid that time.