اﺛﺮ ﻣﺪﻟﺴﺎزي اﺗﺼﺎﻻت ﺗﯿﺮ ﺳﺘﻮن و ﺧﺎك ﺑﺮ رﻓﺘﺎر ﻟﺮزهاي ﻗﺎبﻫﺎي ﺧﻤﺸﯽ ﻓﻮﻻدي ﻣﺘﻮﺳﻂ

The Effect of Beam-Column Connections and Soil on the Seismic Behavior of Intermediate Steel Moment-Resisting Frames

اﻧﺪرﮐﻨﺶ ﺧﺎك – ﺳﺎزه اﺧﺘﻼف ﻣﻮﺟﻮد در ﭘﺎﺳﺦ ﻫﺎي ﺳﺎزه را درﺷﺮاﯾﻂ واﻗﻌﯽ و ﺗﺌﻮري ﺑﺎ ﻓﺮض ﺗﮑﯿﻪ ﮔﺎه ﺻﻠﺐ ﺑﯿﺎن ﻣﯽ ﮐﻨﺪ و ﺑﻪ ﻣﺸﺨﺼﺎﺗﯽ ﻫﻤﭽﻮن ﺳﺨﺘﯽ، ﺟﺮم و ﻣﯿﺮاﯾﯽ ﺧﺎك و ﺳﺎزه ﺑﺴﺘﮕﯽ دارد. ﺳﺎﺧﺘﻤﺎن هاي داراي ﻗﺎب ﺧﻤﺸﯽ از ﺟﻤﻠﻪ ﺳﯿﺴﺘﻤ هاي ﺳﺎزه اي ﻫﺴﺘﻨﺪ ﮐﻪ اﻣﺮوزه از ﻓﺮاواﻧﯽ ﻧﺴﺒﺘﺎ ﺑﺎﻻﯾﯽ ﺑﺮﺧﻮردار ﻫﺴﺘﻨﺪ. در اﯾﻦ ﻧﻮع ﻗﺎﺑﻬﺎ ﺷﮑﻞ ﭘﺬﯾﺮي ﺗﻮﺳﻂ ﻋﻮاﻣﻠﯽ ﻫﻤﭽﻮن ﺗﺴﻠﯿﻢ ﺧﻤﺸﯽ ﺗﯿﺮﻫﺎ، ﺳﺘﻮﻧﻬﺎ و ﺗﺴﻠﯿﻢ ﺑﺮﺷﯽ ﭼﺸﻤﻪ اﺗﺼﺎل ﺳﺘﻮن ﺣﺎﺻﻞ ﻣﯽ ﮔﺮدد. در اﯾﻦ ﻣﻘﺎﻟﻪ، ﺗﺎﺛﯿﺮ ﻣﺪﻟﺴﺎزي اﺗﺼﺎﻻت ﺗﯿﺮ – ﺳﺘﻮن و اﻧﺪرﮐﻨﺶ ﺧﺎك – ﻓﻮﻧﺪاﺳﯿﻮن - ﺳﺎزه ﺑﺮ ﭘﺎﺳﺦ ﻟﺮزه اي ﺳﺎﺧﺘﻤﺎﻧﻬﺎي 10 ﻃﺒﻘﻪ ﺑﺎ ﺳﯿﺴﺘﻢ ﺳﺎزه اي ﻗﺎب ﺧﻤﺸﯽ ﻓﻮﻻدي ﻣﺘﻮﺳﻂ واﻗﻊ ﺑﺮ ﺧﺎك ﻧﻮع IV داراي ﺳﺮﻋﺘﻬﺎي ﻣﻮج ﺑﺮﺷﯽ 150 و 80 ﻣﺘﺮ ﺑﺮ ﺛﺎﻧﯿﻪ و ﺧﺎك ﻧﻮع II ﺑﺎ ﺳﺮﻋﺖ ﻣﻮج ﺑﺮﺷﯽ 560 ﻣﺘﺮ ﺑﺮ ﺛﺎﻧﯿﻪ ارزﯾﺎﺑﯽ ﺷﺪه اﺳﺖ. اﺗﺼﺎﻻت ﺑﮑﺎر رﻓﺘﻪ ﺑﺮاي اﯾﻦ ﺳﺎﺧﺘﻤﺎﻧﻬﺎ از ﻧﻮع اﺗﺼﺎﻻت از ﭘﯿﺶ ﺗﺎﯾﯿﺪ ﺷﺪه ي ﺟﻮﺷﯽ ﺑﻪ ﮐﻤﮏ ورﻗه اي روﺳﺮي و زﯾﺮﺳﺮي WFP)( ﻫﺴﺘﻨﺪ. ﺑﻪ ﻣﻨﻈﻮر ﺑﺮرﺳﯽ ﻋﻤﻠﮑﺮد اﯾﻦ ﺳﺎﺧﺘﻤﺎﻧﻬﺎ، ﻣﺪﻟﻬﺎي اﺟﺰاي ﻣﺤﺪود دو ﺑﻌﺪي ﺑﺎ ﻓﺮض ﻟﺤﺎظ اﺛﺮ ﺧﺎك و اﺗﺼﺎﻻت، ﻟﺤﺎظ اﺛﺮ ﺧﺎك و ﻋﺪم ﻟﺤﺎظ اﺛﺮ اﺗﺼﺎﻻت، ﺗﮑﯿﻪ ﮔﺎه ﺻﻠﺐ و ﺑﺪون ﻟﺤﺎظ اﺛﺮ اﺗﺼﺎﻻت ﺗﻮﺳﻂ ﻧﺮم اﻓﺰار OpenSees ﺳﺎﺧﺘﻪ ﺷﺪه اﻧﺪ. اﯾﻦ ﻣﺪﻟﻬﺎ ﺗﺤﺖ ﺗﺤﻠﯿل هاي دﯾﻨﺎﻣﯿﮑﯽ ﺗﺎرﯾﺨﭽﻪ ي زﻣﺎﻧﯽ ﻏﯿﺮﺧﻄﯽ ﻗﺮار ﮔﺮﻓﺘﻪ و ﺣﺪاﮐﺜﺮ ﭘﺎﺳﺦ آﻧﻬﺎ ﺑﺎ ﯾﮑﺪﯾﮕﺮ ﻣﻘﺎﯾﺴﻪ ﮔﺮدﯾﺪه اﺳﺖ. ﻧﺘﺎﯾﺞ ﺑﺪﺳﺖ آﻣﺪه ﻧﺸﺎن ﻣﯽ دﻫﺪ ﮐﻪ در ﻣﺪﻟﻬﺎي واﻗﻊ ﺑﺮ ﺧﺎك ﻧﻮعIV ، ﻟﺤﺎظ اﺛﺮ ﺧﺎك و اﺗﺼﺎﻻت و ﯾﺎ ﻓﻘﻂ اﺛﺮ ﺧﺎك، ﻣﻨﺠﺮ ﺑﻪ اﻓﺰاﯾﺶ ﺣﺪاﮐﺜﺮ ﺗﻐﯿﯿﺮﻣﮑﺎن ﺟﺎﻧﺒﯽ و ﺣﺪاﮐﺜﺮ ﺗﻐﯿﯿﺮﻣﮑﺎن ﻧﺴﺒﯽ ﺑﯿﻦ ﻃﺒﻘﻪ اي ﻧﺴﺒﺖ ﺑﻪ ﻣﺪﻟﻬﺎي ﺑﺪون ﻟﺤﺎظ آﻧﻬﺎ و در ﻣﺪﻟﻬﺎي واﻗﻊ ﺑﺮ ﺧﺎك ﻧﻮع II ﻣﻨﺠﺮ ﺑﻪ ﮐﺎﻫﺶ ﺑﺮﺧﯽ از اﯾﻦ ﭘﺎﺳﺨﻬﺎ ﻣﯽ ﮔﺮدد. در ﮐﻠﯿﻪ ي ﻣﺪﻟﻬﺎ، ﻟﺤﺎظ اﯾﻦ دو ﻋﺎﻣﻞ ﺑﺎﻋﺚ ﮐﺎﻫﺶ ﺣﺪاﮐﺜﺮ ﺑﺮش ﭘﺎﯾﻪ ﻣﯽ ﺷﻮد.

Soil-structure interaction expresses the difference of structural responses between the actual and theoretical rigid based conditions, and depends on the stiffness, mass and damping of soil and structure systems. Nowadays, moment-resisting frame is one the most applicated structural systems. Ductility of these frames is due to the flexural yielding of beams, columns and the shear yielding of panel zone of columns. The influence of modeling beam-column connections and soil-foundation-structure interaction on the seismic responses of 10-story intermediate steel moment-resisting frames that located on the soil type IV with various shear wave velocities (150 and 80 m/s) and soil type II (with shear wave velocities 56 m/s) is studied in this paper. Prequalified welded flange plate connections (WFP) are used in these buildings. For this purpose, several 2D finite element models are developed using OpenSees software by assuming three conditions such as models with considering soil and beam-column connections effects, models with considering soil and without connections, models with fixed based and without considering connections. The maximum responses of the studied frames are calculated and compared with nonlinear time-history dynamic analyses. The numerical results show that in the models located on soil type IV, considered connections, SFSI, or just soil, the maximum lateral displacement and maximum inter-story drift are more, compare to models without connections and with fixed based conditions. In the models rested on soil type II, some of these parameters are reduced. The maximum base shear of structures is reduced in the mentioned models.