ﺑﺮرﺳﯽ ﺗﺎﺛﯿﺮ آﭘﻠﯿﻔﺖ ﺑﺮآﺳﯿﺐ ﻟﺮزهاي ﺳﺪ ﺑﺘﻨﯽ وزﻧﯽ در زﻟﺰﻟﻪﻫﺎي ﺣﻮزه دور وﻧﺰدﯾﮏ: ﻣﻄﺎﻟﻌﻪ ﻣﻮردي ﺳﺪ ﺷﻔﺎرود

Investigation of Uplift force effects on Seismic Damage of Concrete Gravity Dam in the Near-Fault and Far-Fault Ground Motions:Case Study Shafaroud Dam

در ﻣﻘﺎﻟﻪ ﺣﺎﺿﺮ ﺗﺎﺛﯿﺮ ﻧﯿﺮوي آﭘﻠﯿﻔﺖ )زﯾﺮﻓﺸﺎر( ﺑﺮ ﭘﺎﺳﺦ دﯾﻨﺎﻣﯿﮑﯽ ﻏﯿﺮﺧﻄﯽ ﺳﺪ ﺑﺘﻨﯽ وزﻧﯽ ﺗﺤﺖ زﻣﯿﻦ زﻟﺰﻟﻪﻫﺎي ﺣﻮزه ﻧﺰدﯾﮏ و ﺣﻮزه دور از ﮔﺴﻞ ﺑﺎ اﺳﺘﻔﺎده ﻣﺪل ﻋﺪدي ﻣﻮرد ﻣﻄﺎﻟﻌﻪ ﻗﺮار ﮔﺮﻓﺘﻪ اﺳﺖ.ﺑﺎ ﺗﻮﺟﻪ ﺑﻪ اﯾﻨﮑﻪ ﻧﯿﺮوي ﻓﺸﺎر آﭘﻠﯿﻔﺖ ﺑﻪ ﻋﻨﻮان ﯾﮑﯽ از ﺑﺎرﮔﺬاريﻫﺎي ﺗﺎﺛﯿﺮﮔﺬار ﺑﺮﭘﺎﯾﺪاري ﺳﺪﻫﺎي ﺑﺘﻨﯽ وزﻧﯽ ﻫﻤﻮاره ﻣﻄﺮح ﻣﯽﺑﺎﺷﺪ، ﻟﺬا درﻣﻄﺎﻟﻌﻪ ﺣﺎﺿﺮ ﺗﺎﺛﯿﺮ اﯾﻦ ﻧﻮع ﺑﺎرﮔﺬاري در ﺷﺮاﯾﻂ ﻣﺨﺘﻠﻒ ﺑﺎ ﻓﺮض ﺳﻪ ﻧﻮع ﺗﻮزﯾﻊ ﻣﺤﺘﻤﻞ ﺑﺮرﺳﯽ ﺷﺪه اﺳﺖ. ﻫﻤﭽﻨﯿﻦ ﺟﻬﺖ ﺑﺮرﺳﯽ دﻗﯿﻖﺗﺮ ﻣﻮﺿﻮع ﺷﺘﺎبﻧﮕﺎﺷﺖﻫﺎي ﺣﻮزه ﻧﺰدﯾﮏ و دور در ﺳﻪ، زﻟﺰﻟﻪ ﻣﺘﻔﺎوت ﺑﺮ ﺳﺎزه ﺳﯿﺴﺘﻢ ﺳﺪ -ﻣﺨﺰن -ﻓﻮﻧﺪاﺳﯿﻮن اﻋﻤﺎل ﮔﺮدﯾﺪه اﺳﺖ. ﻣﺪل ﺧﺮاﺑﯽ ﭘﻼﺳﺘﯿﮏ ﺑﺘﻦCDP)( ﮐﻪ ﺷﺎﻣﻞ رﻓﺘﺎر ﺳﺨﺖ ﺷﻮﻧﺪﮔﯽ و ﻧﺮم ﺷﻮﻧﺪﮔﯽ ﮐﺮﻧﺸﯽ ﺑﺘﻦ ﻣﯽﺑﺎﺷﺪ در ﺗﺤﻠﯿﻞ دﯾﻨﺎﻣﯿﮑﯽ ﻏﯿﺮﺧﻄﯽ ﺑﮑﺎر رﻓﺘﻪ اﺳﺖ. ﺑﻌﻨﻮان ﻣﻄﺎﻟﻌﻪ ﻣﻮردي ﺗﺤﻠﯿﻞ دﯾﻨﺎﻣﯿﮑﯽ ﻏﯿﺮﺧﻄﯽ و آﻧﺎﻟﯿﺰ ﺧﺮاﺑﯽ ﻟﺮزهاي ﺳﺪ ﺑﺘﻨﯽ وزﻧﯽ ﺷﻔﺎرود واﻗﻊ در اﺳﺘﺎن ﮔﻠﺴﺘﺎن ﺗﺤﺖ زﻣﯿﻦ ﻟﺮزهﻫﺎي ﺣﻮزه دور و ﻧﺰدﯾﮏ ﺑﺎﻫﻤﺮاه ﻟﺤﺎظ اﺛﺮات ﻧﯿﺮوي زﯾﺮﻓﺸﺎر ﻣﻮرد ارزﯾﺎﺑﯽ ﻗﺮار ﮔﺮﻓﺘﻪ اﺳﺖ. اﻧﺪﯾﺲ ﺧﺮاﺑﯽ ﮐﻠﯽ ﺑﻌﻨﻮان ﯾﮑﯽ از ﭘﺎراﻣﺘﺮﻫﺎي ﭘﺎﺳﺦ ﻟﺮزهاي ﺳﺪ ﻣﻮرد ﺑﺮرﺳﯽ اراﺋﻪ ﮔﺮدﯾﺪه اﺳﺖ. ﻧﺘﺎﯾﺞ ﺑﺪﺳﺖ آﻣﺪه از ﺗﺤﻠﯿﻞ ﺳﺪ ﺑﺘﻨﯽ وزﻧﯽ ﺗﺤﺖ ﺗﺎﺛﯿﺮ ﻫﺮ ﯾﮏ از زﻣﯿﻦ ﻟﺮزهﻫﺎي ﺣﻮزه ﻧﺰدﯾﮏ و دور ﺑﻪ ﻫﻤﺮاه ﺳﻪ ﺗﻮزﯾﻊ ﻣﺘﻔﺎوت ﻧﯿﺮوي آﭘﻠﯿﻔﺖ ﻣﻘﺎﯾﺴﻪ ﺷﺪه ﺑﻄﻮرﯾﮑﻪ ﻧﺘﺎﯾﺞ ﺑﺪﺳﺖ آﻣﺪه از ﺗﺤﻠﯿﻞ ﺣﺎﮐﯽ از ﺗﺎﺛﯿﺮ ﻧﺴﺒﯽ ﻧﯿﺮوي آﭘﻠﯿﻔﺖ در زﻣﯿﻦ ﻟﺮزهﻫﺎي ﺣﻮزه ﻧﺰدﯾﮏ ﺑﺮ رﻓﺘﺎر دﯾﻨﺎﻣﯿﮑﯽ ﺳﺪ ﺑﺘﻨﯽ وزﻧﯽ ﻣﯽﺑﺎﺷﺪ ﺑﻄﻮرﯾﮑﻪ در اﯾﻦ ﺷﺮاﯾﻂ ﺗﺨﺮﯾﺐ ﺑﺪﻧﻪ ﺳﺪ ﺑﻄﻮرﻧﺴﺒﯽ اﻓﺰاﯾﺶ ﻣﯽﯾﺎﯾﺪ.

Uplift force has significant role on dynamic response of concrete gravity dams and also seismic response of dams in near field motion can be considerably different from those observed in the far field and the near –fault ground motions can cause considerable damage during an earthquake. This paper presents results of study aimed at evaluating the uplift force effects in the near-fault and far-fault ground motions on nonlinear dynamic response and seismic damage of concrete gravity dams including dam-reservoir-foundation interaction. For this purpose, 3 as-recorded earthquake records which display ground motions with an apparent velocity pulse are selected to represent the near-fault ground motion characteristics. The Shafaroud gravity dam, which is selected as a numerical application, is subjected to a set of as-recorded near-fault and far-fault strong ground motion records and three different distribution of uplift force are assumed. The results obtained from the analysis of the dam subjected to each fault effect are compared with each other. It is seen from the analysis results that the uplift force, which has influence on the dynamic response of concrete gravity dam-reservoir-foundation systems subjected to near-fault ground motion, as has the potential to increase damage in the dam body but at far-fault motion uplift force can be neglected.