Research Of Complex Structure Time-dependent Analysis And Design Method

Traditional structure design method is used to design the structure which isin use. The analysis model is the whole model and the entire load is applied atthe same time without consideration of influence of constructing process. In fact,the boundary condition, load level and the material properties is changing duringthe construction process. This phenomenon is called time-dependentcharacteristics. It is these time-varying factors, the incompletion of theconstruction process and the resisting force that make the probabi lity of risk andfailure higher. The influence of increasing construction scale, longer buildingtime and accelerating building speed on structure is more and more important. Tosupport the improvement of traditional structure design method, It is necessary tomodify it and consider the time-dependent characteristics of construction process.Based on the above situation, the following work has been done:(1) Investigation and statistics of constructing live loads and establishmentof model.Mass data of78different projects has been collected by field study andquestionnaire. Using statistical parameters and probability distribution fu nctionwhich is deduced by the method for parameter estimation and hypothesis testing,a probability distribution model which is based on exponential and gammadistribution. To provides reference for the value of construction loads, somevalue is recommended according to certain guarantee rate.(2) Time-dependent analysis and design method of structuresArranges and studies of the time-dependent analysis method of long-spanspaced structures and high-level buildings have been done. Many time-dependentconstruction technologies have been collected, such as assembly analysis method,unloading analysis method, prestressed form finding analysis method, high-levelbuilding time-dependent analysis method. Lifting simulation method of irregularstructure is studied, providing references for choosing analysis method oftime-dependent process. The time-dependent analysis method is introduced totraditional structure design. Design process framework is established, whichtakes time-dependent member into consideration. Technical support is provided for the improvement of structure design method.(3) The time-dependent analysis of streamer grid in Hangzhou InternationalExpo Center.Time-dependent method is applied to analysis the streamer grid inHangzhou International Expo Center. This paper compares the structureresponses with different cable length and suspension points. Reasonable cablelength and suspension points is provided. The stress and strain response patternof assembly and unloading process can provide theo retical foundation for safeand exact construction. The analysis result can guide the construction processsuccessfully and safely, which proves the reliability of time-dependent analysismethod.