Rehabilitation of Portal Subsidence of Heybat Sultan Twin Tunnels: Selection of Shotcrete or Geogrid Alternatives
Ako Abdullah Daraei
ako.daraei@cihanuniversity.edu.iq
Abstract- The occurrence of karst phenomenon is one of the common problems in carbonate rocks in the presence of water. The rock masses constituting the ground surface are mostly of sedimentary types among which carbonate rocks are widely observed. It is therefore necessary to accept such a geological hazard in many projects. Some of the rehabilitation methods for karstic subsidence include grout injection, filling with concrete or shot Crete and making use of geosynthetic products. Few studies have been carried out on the application of the geosynthetic products. Limy rocks form the main lithology of a large part of the 72 km long access road tunnel designed for the Iraqi-Kurdistan. The occurrence of a karstic subsidence with a volume of about 2250 m3 in the portal of Heybat Sultan tunnels revealed the necessity of examining and selecting one of these rehabilitation methods
Keywords- Subsidence · Karst · Geogrid · Shotcrete · Tunneling
Date: 22/5/2021
Place: Department of Civil Engineering