ارزيابي عددي اثر فشار و تراوش آب در طراحي تونلهاي تحت فشار

Numerical Evaluation of Pressure and Water Leakage in the Design of Pressure Tunnels

ﺗﻮﻧﻠﻬﺎ و ﺷﻔﺘﻬﺎي ﺗﺤﺖ ﻓﺸﺎر در اﺑﺘﺪا در ﺻﻨﻌﺖ ﻫﯿﺪرواﻟﮑﺘﺮﯾﮏ ( ﻧﯿﺮوﮔﺎﻫﻬﺎي ﺑﺮق آﺑﯽ) اﺳﺘﻔﺎده ﻣﯽ ﺷﺪﻧﺪ، اﻣﺎ اﮐﻨﻮﻧﺒﺮاي اﻧﺘﻘﺎل آب ﻣﺼﺮﻓﯽ و ﺿﺎﯾﻌﺎت آﺑﯽ اﺳﺘﻔﺎده ﻣﯽ ﺷﻮﻧﺪ. اﻣﺎ ﻫﻨﻮز ﻋﻤﻮﻣﯽ ﺗﺮﯾﻦ اﺳﺘﻔﺎده از ﺗﻮﻧﻠﻬﺎ و ﺷﻔﺖ ﻫﺎي ﺗﺤﺖ ﻓﺸﺎردر ﻃﺮح ﻧﯿﺮوﮔﺎﻫﻬﺎي ﺑﺮق آﺑﯽ ﺟﻬﺖ اﻧﺘﻘﺎل آب از ﺑﺎﻻدﺳﺖ ﺑﻪ ﻧﯿﺮوﮔﺎه ﭘﺎﯾﯿﻦ دﺳﺖ اﺳﺖ. در اﯾﻦ ﭘﺎﯾﺎن ﻧﺎﻣﻪ، ﺟﻬﺖ روﺷﻦ ﺷﺪن ﻫﺪف اﺻﻠﯽ ﺗﺤﻘﯿﻖ ﮐﻪ ارزﯾﺎﺑﯽ ﻋﺪدي اﺛﺮ ﻓﺸﺎر و ﺗﺮاوش آب در ﻃﺮاﺣﯽ ﺗﻮﻧﻞ ﻫﺎي ﺗﺤﺖ ﻓﺸﺎراﺳﺖ، ﺑﻪ روش اﺟﺰاي ﻣﺤﺪود ﺑﺎ اﺳﺘﻔﺎده از ﻧﺮم اﻓﺰار 3DPLAXIS ﭼﻨﺪﯾﻦ ﺳﯿﺴﺘﻢ ﺳﺎزه اي ﺗﻮﻧﻞ ﺗﺤﺖ اﺛﺮ ﻓﺸﺎر ﺑﺎ ﺳﻄﻮح ﻣﺨﺘﻠﻒ آب زﯾﺮ زﻣﯿﻨﯽ و ﺳﺮﺑﺎرﻫﺎي ﻣﺘﻔﺎوت ﺗﺤﺖ اﺛﺮ ﻓﺸﺎر و ﺗﺮاوﺷﻤﺪﻟﺴﺎزي و ﻣﻮرد ﺗﺤﻠﯿﻞ واﻗﻊ ﺷﺪه اﺳﺖ. در ﻣﺠﻤﻮع 32 ﻣﺪل ﮐﻪ ﺷﺎﻣﻞ 4 ﻧﺴﺒﺖ ارﺗﻔﺎع ﺳﺮﺑﺎر ﺑﻪ ﻗﻄﺮ ﺗﻮﻧل (H/D) و 4 ﻧﺴﺒﺖ ﺗﺮاز آب زﯾﺮ زﻣﯿﻨﯽ ﺑﻪ ارﺗﻔﺎع ﺳﺮﺑﺎر ﺗﻮﻧﻞ (h/ H) ﺗﺤﻠﯿﻞ و ﺑﺮرﺳﯽ ﺷﺪ.در اﯾﻦ ﺗﺤﻘﯿﻖ اﺑﺘﺪا ﺑﻪ ارزﯾﺎﺑﯽ ﻧﺘﺎﯾﺞ ﺣﺎﺻﻞ از ﺗﺤﻠﯿﻞ اﺟﺰاء ﻣﺤﺪود ﺗﻮﻧﻞ ﻫﺎي ﺗﺤﺖ ﻓﺸﺎر ﻫﻤﭽﻮن ﺗﻐﯿﯿﺮ ﺷﮑﻞ ﺗﻐﯿﯿﺮ ﻣﮑﺎن و ﺗﻨﺶ ﻫﺎي وارده ﺑﺮ ﻧﻤﻮﻧﻪ ﻫﺎ ﺑﺮ ﻣﺒﻨﺎي ﺗﻐﯿﯿﺮ ﻣﯿﺰان ﺗﺮاز ﺳﻄﺢ آب زﯾﺮ زﻣﯿﻨﯽ و ﺳﺮﺑﺎر ﺗﻮﻧﻞ ﭘﺮداﺧﺘﻪ ﺷﺪ، ﺳﭙﺲ ﮐﺮﻧﺶ ﮐﻠﯽ، ﮐﺮﻧﺶ ﺑﺮﺷﯽ و در ﻧﻬﺎﯾﺖ ﻧﯿﺮوﻫﺎي ﻣﺤﻮري، ﺑﺮﺷﯽ و ﻟﻨﮕﺮ ﺧﻤﺸﯽ ﻧﻤﻮﻧﻪ ﻫﺎي ﻣﻮرد ﻣﻄﺎﻟﻌﻪ و ﻋﻤﻠﮑﺮد ﻣﯿﺦ ﻫﺎ و دﯾﻮاره ﻫﺎ ﺑﺮ اﺳﺎس ﺗﻐﯿﯿﺮات ﻧﺴﺒﺖ ارﺗﻔﺎع ﺳﺮﺑﺎر ﺑه ﻗﻄﺮ ﺗﻮﻧﻞ (H/D) و ﻧﺴﺒﺖ ﺗﺮاز آب زﯾﺮ زﻣﯿﻨﯽ ﺑﻪ ارﺗﻔﺎع ﺳﺮﺑﺎر ﺗﻮﻧﻞ (h/ H) ﻣﻮرد ﺑﺮرﺳﯽ ﻗﺮار ﮔﺮﻓﺖ.

Pressure tunnels and shafts were initially used in the hydroelectric industry (hydroelectric power plants), but are now used to transport consuming water and waste water. But still the most common use of pressure tunnels and shafts is the design of hydroelectric power plants to transfer water from the upstream to the downstream power plant .In this thesis, in order to clarify the main purpose of the research, which is the numerical evaluation of the effect of pressure and water leakage in the design of pressure tunnels by finite element method using the 3DPLAXIS software, several structural systems of the pressure tunnel with various levels of groundwater and different overheads under the influence of pressure and leakage are modeled and analyzed. A total of 32 models, including 4 overhead height ratio to tunnel diameter (H/D) and 4 groundwater level ratios to tunnel overhead height (h/ H) were analyzed. In this research, firstly, the evaluation of the results of the analysis of the limited components of pressure tunnels such as deformation (displacement) and tensions on samples based on changes in the rate of groundwater level and tunnel overhead were studied, then, the general strain, shear strain and finally the axial , shear forces and bending anchor of the studied samples and the performance of the nails and walls based on changes in the ratio of overhead height to tunnel diameter (H/D) and the ratio of groundwater level to tunnel overhead height (h/H) were studied .