آﻧﺎﻟﯿﺰ ﻧﺸﺖ در ﭘﯽ و ﺑﺪﻧﻪ ﺳﺪ ﺧﺎﮐﯽ ﺑﺎ اﺳﺘﻔﺎده از ﻣﺪﻟﺴﺎزي ﻋﺪدي-ﻣﻄﺎﻟﻌﻪ ﻣﻮردي

Seepage analyses in the foundation and body of earth dam using numerical modeling -A case study

ﯾﮑﯽ از ﻣﻬﻤﺘﺮﯾﻦ ﻣﺴﺎﺋﻞ در ﻃﺮاﺣﯽ ﺳﺪﻫﺎي ﺧﺎﮐﯽ ﮐﻪ در ﻣﻮاردي اﺣﺪاث ﺳﺪ را در ﯾﮏ ﻣﻨﻄﻘﻪ ﻏﯿﺮ ﻗﺎﺑﻞ ﺗﻮﺟﯿﻪ ﻣﯽ ﻧﻤﺎﯾﺪ، ﻣﻘﺪار ﻓﺮار آب از ﻣﺨﺰن ﺳﺪ از ﻃﺮﯾﻖ ﭘﯽ و ﺑﺪﻧﻪ اﺳﺖ. ﻟﺬا ﻣﺤﺎﺳﺒﻪ دﻗﯿﻖ ﻣﻘﺪار دﺑﯽ ﻧﺸﺖ از ﺑﺪﻧﻪ و ﭘﯽ ﺳﺪ از ﺟﻬﺎت ﻓﻨﯽ و اﻗﺘﺼﺎدي ﺣﺎﺋﺰ اﻫﻤﯿﺖ ﻓﺮاواﻧﯽ اﺳﺖ. آﻧﺎﻟﯿﺰ ﻧﺸﺖ در ﻃﺮاﺣﯽ ﯾﮏ ﺳﺪ ﺧﺎﮐﯽ از ﻟﺤﺎظ اﯾﻤﻨﯽ ﺳﺪ ﻧﯿﺰ ﻣﻬﻢ ﻣﯽ ﺑﺎﺷﺪ زﯾﺮا ﺟﺮﯾﺎن آب در ﺑﺪﻧﻪ و ﭘﯽ ﺳﺪ ﺑﺎﻋﺚ ﺑﻮﺟﻮد آﻣﺪن ﻓﺸﺎر ﺣﻔﺮه اي و ﻧﯿﺮوﻫﺎي ﺗﺮاوﺷﯽ ﻣﯽ ﺷﻮد، ﮐﻪ اﮔﺮ ﻣﻘﺪار اﯾﻦ ﻧﯿﺮوﻫﺎ در ﺣﺪ ﻣﺠﺎز ﻧﺒﺎﺷﺪ، ﭘﺎﯾﺪاري ﻣﺼﺎﻟﺢ ﺑﺪﻧﻪ و ﭘﯽ ﺳﺪ دﭼﺎر ﻣﺸﮑﻼت ﻋﻤﺪه اي از ﻗﺒﯿﻞ رﮔﺎب و آب ﺷﺴﺘﮕﯽ ﺧﻮاﻫﺪ ﺷﺪ، ﮐﻪ در ﻧﺘﯿﺠﻪ ﺑﻪ ﺧﺮاﺑﯽ ﺳﺪ ﺧﻮاﻫﺪ اﻧﺠﺎﻣﯿﺪ. ﺑﻨﺎﺑﺮاﯾﻦ ﻻزم اﺳﺖ ﺗﺎ ﺑﻪ ﻣﻨﻈﻮر ﺟﻠﻮﮔﯿﺮي از ﺧﺮاﺑﯽ ﻫﺎي ﺣﺎﺻﻞ از زه آب، ﻣﻘﺪار ﺟﺮﯾﺎن زه در ﺑﺪﻧﻪ و ﺷﺎﻟﻮده ﺳﺪ ﺧﺎﮐﯽ ﺑﻪ ﻃﻮر دﻗﯿﻖ ﺗﻌﯿﯿﻦ ﺷﻮد. در اﯾﻦ ﻣﻘﺎﻟﻪ ﺑﻪ ﻣﻨﻈﻮر آﻧﺎﻟﯿﺰ ﻧﺸﺖ در ﺳﺪ ﺧﺎﮐﯽ رودﺑﺎر ﻟﺮﺳﺘﺎن )ﻣﻄﺎﻟﻌﻪ ﻣﻮردي( از ﻣﺪﻟﺴﺎزي ﻋﺪدي )روش اﻟﻤﺎن ﻣﺤﺪود( در ﻧﺮم اﻓﺰار Slide اﺳﺘﻔﺎده ﺷﺪه اﺳﺖ. ﻧﺘﺎﯾﺞ ﺣﺎﺻﻞ از ﻣﺪﻟﺴﺎزي ﻋﺪدي و ﻣﺤﺎﺳﺒﺎت زه آب ﻋﺒﻮري از ﻣﻘﻄﻊ ﻋﺮﺿﯽ ﭘﯽ و ﺑﺪﻧﻪ ﺳﺪ رودﺑﺎر ﻟﺮﺳﺘﺎن ﻧﺸﺎن ﻣﯽ دﻫﺪ ﮐﻪ ﺑﻪ ﻃﻮر ﺳﺎﻟﯿﺎﻧﻪ ﺑﺮاﺑﺮ ﺑﺎ 629584 ﻣﺘﺮ ﻣﮑﻌﺐ ﺑﺮآورد ﻣﯽ ﺷﻮد ﮐﻪ ﻣﻌﺎدل 0/27 درﺻﺪ ﺣﺠﻢ آب ﺳﺪ )1724 ﻣﺘﺮ ﻣﮑﻌﺐ در روز: ﺳﻬﻢ ﺑﺪﻧﻪ ﺳﺪ 98 درﺻﺪ و ﺳﻬﻢ ﭘﯽ ﺳﻨﮕﯽ 2 درﺻﺪ( ﻣﯽ ﺑﺎﺷﺪ ﮐﻪ ﺑﺎ ﺗﻮﺟﻪ ﺑﻪ ﺟﻨﺲ ﻣﺼﺎﻟﺢ ﻫﺴﺘﻪ ﻗﺎﺑﻞ ﻗﺒﻮل ارزﯾﺎﺑﯽ ﻣﯽ ﺷﻮد. ﻫﻤﭽﻨﯿﻦ ﻣﺪﻟﺴﺎزي اﻧﺠﺎم ﺷﺪه ﻧﺸﺎن ﻣﯽ دﻫﺪ ﺳﺪ ﺧﺎﮐﯽ رودﺑﺎر ﻟﺮﺳﺘﺎن داراي ﺿﺮﯾﺐ اﯾﻤﻨﯽ ﺑﺴﯿﺎر ﺑﺎﻻﯾﯽ در ﺑﺮاﺑﺮ ﭘﺪﯾﺪه رﮔﺎب اﺳﺖ.

Dams are mainly constructed of earth and rock-fill materials and hence they are generally referred to as embankment dams orfill-type dams. The role of drainage system is also vital as it shifts the phreatic surface ensuring the safety of downstreamtoe. This paper presents the results of seepage analyses of the considered earth dam using finite element method. Slide software is one of geotechnical program that is based on the finite element and canconsider analysis like stress-strain, seepage, slope stability, dynamic analysis and also fast water drop inreservoir. In this research seepage analysis in Roudbar Lorestan dam has been done by Slide software. In orderto evaluate the type and size of mesh size on the total flow rate and total head through the dam cross section,four mesh size such as coarse, medium, fine and unstructured mesh is considered. Result showed that averageflow rate of leakage under the different mesh size for Roudbar Lorestan dam equal 629584 m3 per year for the entire lengthof the dam.