عنوان مقاله [English]
The reinforced concrete Tunnel Form Building (TFB) is a new industrialized building system in which only the slabs and walls contribute to the lateral load resisting system. Its appellation ``the tunnel form'' is due to the installation of formworks in box manner. In spite of its superiority in terms of resistance to earthquake excitations, the current seismic code provisions present limited information for the seismic design criteria. The high computational cost is one of the problems facing the structural engineering profession to evaluate the seismic performance of TFBs in the range of nonlinear deformation behavior. It seems that the Endurance Time (ET) method is a solution to remedy this shortcoming. The ET method originally is a time-history based dynamic pushover procedure for seismic analysis of structures. In this procedure, the structure is subjected to a specially
designed intensifying accelerogram and its endurance time is measured based on the time interval during which it can resist the imposed dynamic actions.In this study, the seismic performances of five and ten-storey TFBs designed in accordance with Iranian seismic code were examined. To this end, the Nonlinear Static Procedure (NSP) and the Nonlinear Dynamic Procedure (NDP), as well as the ET method, were utilized. The results of this study indicate the attainment of their performances in immediate occupancy performance level under the design earthquake (the return period of 475 years) as well as the high accuracy of the ET method in estimating the structural response with less computational effort with respect to the other methods. The maximum of %53.76 and %21.74 errors may be observed for NSP and ET method, respectively, concerning high-accuracy of NDP in the estimation of the structural responses as well as much less computational effort. The time taken to perform the ET analysis is only %20 and %25 of the time required for NSP and NDP, respectively. According to the proper accuracy of ET method in predicting the seismic responses, with respect to NSP and NDP, it seems that the ET method can be considered an alternative for the current traditional methods, especially for TFB system.