ﺑﺮآورد ﻋﺪدي و ﺗﺤﻠﯿﻠﯽ ﻧﺸﺴﺖ ﺳﻄﺢ زﻣﯿﻦ ﻧﺎﺷﯽ از ﺗﻮﻧﻠ ﺴﺎزي ﺑﺎ ﺳﭙﺮ ﺗﻌﺎدﻟﯽ زﻣﯿﻦ -ﻣﻄﺎﻟﻌﻪﻣﻮردي؛ ﺧﻂ ﻫﻔﺖ ﻣﺘﺮوي ﺗﻬﺮان

Applying Numerical Analysis and Analytical Solution for Predicting of ground settlement due to EPB Shield tunneling (Case study, Seventh line of Tehran subway)

در اﯾﻦ ﻣﻘﺎﻟﻪ، ﭘﯿﺶ ﺑﯿﻨﯽ ﻣﻘﺪار ﺟﺎﺑﺠﺎﯾﯽ ﻫﺎي ﻋﻤﻮدي )ﻧﺸﺴﺖ( در اﺛﺮ ﺣﻔﺮ ﺗﻮﻧﻞ در ﭼﻬﺎر ﻣﻘﻄﻊ )در ﻣﺤﻞ ﮔﻤﺎﻧﻪ ﻫﺎي M7 ،V7 ،W7 و G6G7( از ﻣﺴﯿﺮ ﺧﻂ ﻫﻔﺖ ﻣﺘﺮوي ﺗﻬﺮان ﺑﺮرﺳﯽ و ﺑﺪﻟﯿﻞ ﻣﺤﺪودﯾﺖ زﻣﺎﻧﯽ ﺗﻨﻬﺎ ﻧﺘﺎﯾﺞ ﺑﺮرﺳﯽ ﮔﻤﺎﻧﻪ G6G7 اراﺋﻪ ﺷﺪه اﺳﺖ. ﺑﺮاي ﭘﯿﺶ ﺑﯿﻨﯽ ﻧﺸﺴﺖ در ﺳﻄﺢ زﻣﯿﻦ از روش ﻫﺎي ﺗﺤﻠﯿﻠﯽ )روش ﺑﺎﺑﺖ( و ﻋﺪدي )روش ﺗﻔﺎﺿﻞ ﻣﺤﺪود ﺑﻪ ﮐﻤﮏ ﻧﺮم اﻓﺰار FLAC2D( اﺳﺘﻔﺎده ﺷﺪه و در ﻧﻬﺎﯾﺖ ﻧﺘﺎﯾﺞ دو روش ﺑﺎ ﻫﻢ ﻣﻘﺎﯾﺴﻪ ﺷﺪه اﻧﺪ. ﻧﺘﺎﯾﺞ روش ﻋﺪدي ﻧﺸﺎن ﻣﯽ دﻫﺪ ﮐﻪ ﻣﯿﺰان ﻣﺎﮐﺰﯾﻤﻢ ﻧﺸﺴﺖ زﻣﯿﻦ در اﯾﻦ 4 ﻣﻘﻄﻊ ﺑﯿﺶ از ﺣﺪ ﻣﺠﺎز )ﺣﺪ ﻣﺠﺎز ﻧﺸﺴﺖ، 2 ﺳﺎﻧﺘﯽ ﻣﺘﺮ در زﯾﺮ ﺧﯿﺎﺑﺎن و 1 ﺳﺎﻧﺘﯽ ﻣﺘﺮ در زﯾﺮ ﺳﺎﺧﺘﻤﺎن ﻫﺎ( ﻣﯽ ﺑﺎﺷﻨﺪ. ﺑﻪ ﻫﻤﯿﻦ ﻣﻨﻈﻮر در ﯾﮑﯽ از ﻣﻘﺎﻃﻊ )در ﻣﺤﻞ ﮔﻤﺎﻧﻪ G6G7( ﻃﺮح ﭘﯿﺸﻨﻬﺎدي ﺗﺰرﯾﻖ اراﺋﻪ و ﻣﻮرد آﻧﺎﻟﯿﺰ ﻗﺮار ﮔﺮﻓﺖ ﮐﻪ ﺳﺒﺐ ﮐﺎﻫﺶ ﻧﺸﺴﺖ )ﺗﺎ ﺣﺪ ﻣﺠﺎز( در اﯾﻦ ﻣﻘﻄﻊ ﺷﺪ. ﺗﻮاﻓﻖ ﺧﻮب ﺑﯿﻦ ﻧﺘﺎﯾﺞ ﺣﺎﺻﻞ از ﻫﺮ دو روش ﻧﺸﺎن ﻣﯽ دﻫﺪ ﮐﻪ ﻣﻘﺎدﯾﺮ اراﺋﻪ ﺷﺪه در اﯾﻦ ﻣﻄﺎﻟﻌﻪ داراي ﻗﺎﺑﻠﯿﺖ اﻋﺘﻤﺎد ﺑﺎﻻﯾﯽ ﻣﯽ ﺑﺎﺷﻨﺪ

In this research, prediction of vertical displacements (Settlement) caused by tunneling is considered in four section (place of W7, V7, M7 and G6G7 boreholes) of seventh line of Tehran subway. For prediction of the value of Settlement in above sections, finite difference numerical method (FLAC2D) and Bobet analytical solution are used. Finally the results are compared. The numerical results show that the value of Settlement in these sections is 8.59, 6.07, 6.28 and 3.35 cm respectively. Another hand the analytical results are 9.2, 6.1, 6.6 and 6 cm. These values are more than critical ones (i.e. 2 cm in beneath of street and 1 cm in beneath of structures). Thus during the tunneling , suitable efforts such as ground improving should be take place in order to reduction of ground Settlement. For this purpose we propose the grout scheme in G6G7 section and analyze it. As our results show, Settlement value decreases to its critical amount. Good agreement of results shows they have reasonable accuracy.