Tez özetleri Astronomi ve Uzay Bilimleri Anabilim Dalı

Engıneerıng Geologıcal Investıgatıon Of Yusufpaşa – Aksaray Lıne In İstanbul Subway

The rock mass of inner tunnel and surface deformations, cover thickness, cross-section of the excavation, grade of the excavation, surface weights and properties of support systems of Aksaray – Yenikapı line of Istanbul Subway has been investigated in this study as the Thesis of Master of Science in the Institute of Science of Istanbul University

On the LRTS line that will be conjoined in Aksaray - Yenikapı metro stations L,M, KB1 and B1 tunnels are being excavated under average 8–12 m thickness of very shallow

overburden thickness and through Trakya Formation (Carboniferous age) which consist of sandstone, siltstone and claystone consecutively. Therefore, for the security of people and property around the excavation, it is vitally important to investigate the values of deformation along the tunnel axes and its vicinity.

According to the data obtained, surface deformations are highly effected by fault and discontinuity planes related to the fault. Partial excavation method effects development of deformations and the deformations drastically increase with cross-section of the excavation of 4th grade excavations that is getting away from circularity. Together with that, excavations of approximately parallel B1 tunnels increase deformations by effecting each other. The forepoles and face soil nails applied on the tunnel ceiling instead of rock bolts with injection limited the surface deformation values within 7-8 mm. In the segments of the tunnel route where cross-sections change, it has been determined that the surface deformation values increase. Also, in L and M types tunnel cross-sections, equipped wall application that is not destructed till stability gained, has been beneficial and found as a valid parameter to minimize the surface deformation values. A mistake or any lack in forming the support systems after evaluating the relations between the loads of surface structures and deformations it has been determined that the deformation values will rise without depending to the rock mass properties in such shallow tunnels as the LRTS line in this study.