Construction Monitoring And Analysis Of The Whole Erection Process For Large-span Steel Structure

The risk probability of large-span steel structure is higher than others during construction stage because of the complicated construction process, construction method and construction technology. If the large spatial structures have an accident, its influence and consequence is extremely serious. So it is necessary to simulate and monitor the whole erection process of large-span steel structure to make out the mechanics property of structures and study the relevant problems during this process.Restricted by the conditions of construction site, monitoring of long-span spatial structure is mostly aimed at a stage of the construction process, such as unloading, move-up procedure and retractable process, however, monitor of the whole erection process is rare. To overcome the disadvantages of wired sensing, our lab developed a field measuring system based on wireless sensing, and it was applied to the steel structure of the Shaoxing Stadium for monitoring of stress, temperature and displacement of the whole construction process.According to the construction plan, this paper erected the finite element model of construction stage and simulated the whole erection process of the stadium by means of life and death element method. Then this paper studies the stress curve change rule of the whole construction process and gives the absolute stress value of the measured component of the completed construction. Finally the main factors influencing stress changes of the stadium construction phase were summarized.This paper studies two factors (unloading and temperature variation) influencing stress changes of the stadium construction phase respectively. According to the unloading plan, the finite element model of unloading stage was erected and the unloading process of steel structure was simulated. Because of the uncertainty of the boundary conditions, the paper gives the finite element calculated values of different kinds of boundary conditions and the calculated values was compared with the monitoring values. Meanwhile, the temperature variation and the horizontal displacement was monitored, then the temperature effect and asynchronism of unloading was calculated.Thermo stresses of the steel structure will produce in special climate condition (continuous high temperature and low temperature) during construction because of temperature variation. Based on a large amount of monitoring values, this paper analyzed the relationship between temperature and stress and the temperature stress during temperature variation. Then this paper studied the temperature distribution of the structure in non-uniform temperature distributions. Considering the non-uniform temperature distributions, the theoretical value of stress variation of components was achieved by means of the finite element simulation and was compared with the measured data.Through the introduction of the construction monitoring of Shaoxing stadium, this paper puts forward some beneficial exploration of the large space steel structure construction monitoring and accumulates experience for construction diagnosis.