Evaluating the laboratory study results of bi-block (connection pins) elements and waterproof gaskets used in universal tunnel segments of GYH metro tunnel in relation to the water flow in the tunnel

Abstract

In mechanized tunnelling, especially in metro tunnels, water flowing into the tunnel is a big concern for the safety of the tunnel.Segment connection pins (Bi-Blocks) and waterproof gaskets of the segments are the primary elements to stop the water from flowing into the tunnel.In this paper, the tests carried out in the laboratories in order to justify the behaviour of Bi-Blocks and waterproof gaskets concerning water flow into the tunnel are evaluated.Standards used worldwide are also discussed in this respect.Recently, about 110 km of tunnels were driven with TBMs in the Istanbul Airport Metro Project.1.1 million bi-blocks and 438 000 waterproof gaskets were used in the project.A big success was obtained with water flowing into the tunnels.This might be due to the proper selection and tests carried out on bi-blocks and waterproof gaskets using internationally recommended standards, including in situ production control and also proper execution of annulus grouting.Purpose of this manuscript, how can be established a relationship between gasket, bi-block, packer, TBM thrust cylinder force, segment lining, water pressure and leakage.Relevant thrust cylinder load and gasket elasticities affection, gasket elastic recover load and affecting of biblock, additional relation between bi-block pull-out force and water leakage status.These complicated structural joints will be affected all tunnel working schedules.This manuscript includes mathematical evaluations of all the mentioned elements in terms of their calculations and field test assessments.The manuscript contains drawings, calculations, details, and test results that belong to the Gayrettepe -3.International Grand Port Metro Line Project.