چکیده:
The aim of current research is to design inexpensive natural materials, especially energy-absorbing slipping or sliding motion at the foundation of low rise buildings. Dimensions and kind of materials were input to the software and results were compared to the conventional and designed structure based on existing codes. The current system and method would cause structures built with conventional and existing codes, last during severe earthquakes and remain in safe position. The main goal is to provide a low cost base isolation system with natural materials available in the market and its formulation and specifications for a new system structural performance. After an earthquake, a new system structural performance would achieve to IO (immediate occupancy) level. Applications including overall objectives of the projects presenting organizations would involve in crisis management manuals used by contractors to provide innovative style design and construction of such structures. The research models were simulated by finite element and nonlinear dynamic softwares such as SAP and ABAQUS. Numerical and mathematical calculations and conclusions were compared to the results obtained from buildings with natural seismic isolation and conventional designs. In fact the aim is to propose seismic control of structure with the current system. The results have shown that this system would maintain seismic parameters such as drift, maximum roof acceleration and maximum stresses in main members at the optimum range.
خلاصه ماشینی:
In this study the DDD idea has been applied for design of regular steel multi-story buildings, which have rocking motion, by using inclined columns around the central main vertical column of the building at its base level.
The inclined columns, which their bases have been shifted toward the center of the building plan, caused the building to move basically in rocking motion during an earthquake and were equipped with Double-ADAS (DADAS) devices (MG Gray, C Christopoulos and JA Packer)[5], which acted as the main role of energy dissipating devices or fuses.
During an earthquake, horizontal movement of the buildings which would in fact occur at the lower part of the column element, causes week and plastic deformation to develop at the majority of their body, leading to a remarkable energy dissipation and creating a type of hysteretic behavior in shear deformation of foundation, as shown in Figure 2.
رجوع شود به تصویر صفحه Fig. 2- a sample of hysteretic curves of EDD device In Figure 3 the circumferential layer of the base level is shown as multi-linear links with hinge connection at their both ends.
5. Conclusion Based on the numerical results obtained from NLTHA of the conventional building and its counterpart sliding building, subjected to several two-component earthquake records, it can be concluded that: • The suggested structural system is very safe and inexpensive method by using material for arrive the good seismic performance for short and sample rise buildings.