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Improper lifting measures of long-span spatial steel structures during construction process may delay the construction period and even cause safety accidents. Few studies on long-span spatial steel structures considered time-varying mechanical characteristic during construction process. In order to achieve safe and efficient installation in a long-span spatial steel structure, this research presents a time-varying mechanical analysis of the synchronous and asynchronous integral lifting and a single and interlaced point’s asynchronous integral lifting analysis method of a long-span spatial steel structure. The results showed that in the case of asynchronous lifting of single point, the displacement influence on other members is related to the distance. The closer the distance from the lifting point, the greater the influence. In asynchronous integral lifting, the lifting point with large lifting force is first installed to the specified position, and the lifting point with small lifting force is installed to the specified position.

As sustainable structures like steel structures become more widely used, so do their construction issues. Improper lifting measures of long-span spatial steel structures may delay the construction period and even cause safety accidents. These problems have hindered the realization of sustainable buildings. Few studies on long-span spatial steel structures considered time-varying mechanical characteristics during the construction process. During the construction process, it will be found that the installed structure does not meet the required accuracy, and the installed content needs to be removed and re-constructed. This will cause idle work and rework, which will result in a waste of resources and is not conducive to sustainable development. Therefore, it is necessary to study the lifting construction process of long-span spatial steel structures and form a refined construction method. Based on the lifting construction process of the maintenance hangar roof of Chengdu Tianfu International Airport, this study proposes a time-varying mechanical analysis method for synchronous and asynchronous integral lifting of long-span space steel structures basing the Building Information Model (BIM). The force on the lifting point is analyzed during the hoisting construction process when the single-point asynchronous integral lifting and the interlaced point asynchronous integral lifting are carried out. The adverse effect of the displacement difference between lifting points during asynchronous integral lifting is proved. It provides a reference for the safe construction of long-span spatial steel structure lifting and also helps to improve the sustainability of construction projects.

Failure scenarios, which form the basis for accident scenarios, need to be studied to describe the failure behavior of complex systems. This paper proposes a hybrid intelligent method that combines the A * intelligent algorithm with the breadth-first search algorithm to automatically generate the failure scenario of a complex system with the failure scenario tree, while simultaneously calculating the occurrence probability of each failure path and of the whole system. The simulation is guided by the failure behavior rules generated based on expert knowledge. A case study of a power supply system with a warm standby subsystem is conducted. This system is also a multi-state system. The obtained results show that the proposed automatic reasoning can identify key failure scenarios that induce system failure, which can be helpful in the decision-making process.INDEX TERMS Failure scenario, automatic Reasoning, failure behavior rule, guided simulation.