بررسي رفتار ديناميكي غيرخطي ديوار برشي فولادي با ورق نازك داراي اتصال تير به ستون صلب تحت نگاشت‏هاي دور و نزديك گسل

Investigation on Nonlinear Dynamic Behavior of Thin Steel Plate Shear Walls with Rigid Beam to Column Connections under Far and Near Fault Earthquakes

با توجه به پيشرفت‏هاي اخير، محققان شاهد اثرات متفاوت زلزله‏هاي نزديك گسل نسبت به زلزله‏هاي دور از گسل بوده‏اند. در اين مقاله سازه‏هاي كوتاه، ميان و بلند مرتبه كه در آن‌ها از سيستم ديوار برشي فولادي با ورق نازك داراي اتصال صلب استفاده شده است، تحت نگاشت‏هاي دور و نزديك گسل مورد آناليز ديناميكي غيرخطي قرار گرفته و با يكديگر مقايسه گرديده اند. نتايج نشان مي‏دهد كه در سازه هاي كوتاه و ميان مرتبه 3 و 7 طبقه (تا پريود 67/0 ثانيه) اثر حركات حوزه‌‌ي دور از گسل بر پارامترهاي پاسخ سازه به‌طور ميانگين 11 و 37 درصد بيش‌تر از اثر حركات حوزه‌ي نزديك گسل بوده است و در سازه هاي بلند مرتبه 15 و 25 طبقه (با پريود بيش از 67/0 ثانيه) اثر حركات نزديك گسل بر پارامترهاي پاسخ سازه به‌طور ميانگين 60 و 46 درصد بيش‌تر از حركات حوزه‌ي دور از گسل است.

Considering recent developments in earthquake engineering, researchers has detected different effects of earthquakes far and near from the fault. Investigations that have been done in this area show that near fault earthquakes have shorter time period comparing far fault earthquakes and in the velocity of near fault earthquakes, there are one or more impacting pulses with a big domain and period that are result of forward directivity. The pulse movement, impressing massive energy in a short time in near fault earthquakes, result in rotating ductility in some stories and joints, brittle failure of joints, immediate destruction of structure and soft story that have observed in Kobe earthquake in 1995 and Northridge earthquake in 1994. On the other hand in the latest four decades, steel plate shear walls have been considered as a resistant system against lateral loads (wind or earthquake) and have been used in construction of modern buildings and retrofit of existing buildings in the world. This system has appropriate stiffness for controlling displacement of structures. In this paper tall, medium and short buildings that the SPSW with rigid connections has used in their structures are investigated in far and near fault earthquakes. They have analyzed with nonlinear dynamic method and have compared with each other. Results show that in short and average buildings the steel plate shear wall with rigid beam to column connection (up to T=0.67s), effect of movement of far from fault zone on the response parameters are 11% to 37% more than those of near fault and in the tall structures (T > 0.67s) effect of near fault movements on the response parameters is about 46% to 60% more than those in the far fault zone.