ABSTRACT
In metro tunnel excavations, it is important to control surface settlements observed before and after excavation, causing damages to the surface structures. Otherwise, metro tunnel cannot perform the task expected and the advantages of metro tunnel are lost. For this purpose, in this study, short term surface settlements and its effect on buildings are examined in three zones for twin tunnels which are to be excavated between Otogar and Kirazlı stations of Istanbul Metro line, which is 5.8 km in length and 6.5 m in diameter. Geology in the study area is composed of fill, very stiff clay, dense sand, very dense sand, and hard clay, respectively starting from the surface.
During tunnel excavations, 28 buildings with 214 apartments have demolished by Istanbul Metropolitan Municipality because of the damages. New apartments are given to the aggrieved people in return for demolished ones. Also, in total for 364 apartments, together with the apartments that are demolished and evacuated in terms of precaution during tunnel excavation, rent and removal expenditures have been paid off. Demolished buildings, repaired buildings, rent payments and other expenses are in total 35.6 million dollars. Total project cost is 225 million dollars. Consequently, project cost increased 15.8% because of weak and shallow ground conditions. Also, duration time of the EPBMs occurred 27.7% for Lovat and 29.3 % for Herrenknecht.
