ارزيابي برش و زاويه‌ي دريفت ديوارهاي برشي فولادي تقويت‌شده با اتصال صلب تحت تحليل ديناميكي غيرخطي در حوزه‌ها‌ي دور و نزديك گسل

Evaluation of Shear and Drift Angle of Stiffened Steel Plate Shear Walls with Rigid Connections in Non-linear Dynamic Analysis in Far and Near Fault Regions

مطالعات انجام‌شده بر روي تخريب ها و آثار زلزله ها، تفاوت اثرات زلزله ها در حوزه ي نزديك گسل و در خارج از اين محدوده را نشان مي دهد. اهميت مطالعه‌ي حوزه ي نزديك گسل زماني بيشتر مي ‌شود كه ضوابط و طيف طرح لرزه ‌يي در آيين‌نامه‌هاي طرح لرزه‌يي نظير استاندارد 2800 زلزله‌ي ايران براساس فرآيندهاي احتمالاتي و دوره هاي زماني طولاني‌مدت به‌دست‌آمده و فقط حركات در حوزه ي دور را توصيف مي كنند. بدين منظور 3 مدل اجزا محدود ديوار برشي فولادي تقويت‌شده با اتصال صلب 3، 7، و 15 طبقه با 5 دهانه، تحت تحليل ديناميكي غيرخطي تاريخچه‌ي زماني قرار گرفته و نتايج نشان داده است كه ضوابط استاندارد 2800 زلزله‌ي ايران پاسخ‌گوي نيازهاي سازه در حوزه‌ي نزديك نيست. پاسخ هاي سازه شامل برش و زاويه‌ي دريفت، در حوزه ي نزديك بيشتر از حوزه ي دور است و با افزايش ارتفاع، اثرات حوزه‌ي نزديك بيشتر مي شود.

This paper presents research work on earthquake damage, with emphasis on near and far-fault earthquakes. Near-fault region earthquake research is very important regarding the criteria of the current seismic design standard spectrum of Iran (2800 Iran Earthquake regulation), which is based on probabilistic processes and prolonged periods, and describes ground motion in far-fault regions. Over the past four decades, the steel plate shear wall (SPSW) system has been used in a number of buildings in the world as part of the lateral force-resisting system. In today’s designs, the SPSW system is designed to buckle elastically, develop a tension field and, ?nally, to yield under extreme loading. To increase the elastic buckling capacity, the common practice is to increase the web thickness, or to use horizontal and vertical plate stiffeners. In this paper, an investigation into the seismic behavior of stiffened steel plate shear walls with height is undertaken. In this research, three FE models of stiffened steel shear walls with rigid connections, with 3, 7 and 15 stories and five spans, under nonlinear dynamic time history analysis, were evaluated. Results show that structural demands in near-fault regions are more than standard 2800 Iran earthquake regulation (v3) criteria. The average of storey shear in 3 storey models in far fault of 8.64% is more than in near fault. This value in 7 and 15 storey model sequences, 4.4 and 4.49 percent, is more than in near fault. The average of drift angle in near fault in 3, 7 and 15 storey model sequences, 46, 192 and 102 percent, is more than in far fault. Structural responses include shear and drift angle, which, in near-fault regions, is more than in far-fault regions. So, that authenticity, from far-fault regions, in the 3-storey model, is transferred to near-fault in models with greater height. The results show a transition zone in the behavior of the 7 storey model from far-fault to near-fault and, with increased height, near-fault effects are remarkable.