Assessing the efficiency and applicability of contact grouting in the Istanbul Subway

Abstract

Contact grouting is used to fill the cavities between tunnel linings and the host rock and for sealing the joints against water penetration. This paper discusses the modelling of the movement of grout through the Thracian Formation in which the Mecidiyekoy and Gayrettepe stations of the Istanbul Subway were constructed. Water ingress into the tunnel occurred in the strata, which had hitherto been considered relatively impermeable. The model indicated the sections in which grouting was most effective and provided the basis on which more realistic calculations of grout requirements for other sections of the works could be made.