Application of concrete arch method (rib) as a guard structure for drilling in Tehran metro stations

The use of tunnels, tunnels, and mines by humans dates back hundreds or even thousands of years. The construction of communication tunnels and water transfer in mountainous areas to overcome the steep topography has been increasing in recent centuries. In the new era, due to the expansion of cities and the density of population centers in the world and the prediction of much higher density of Yazr cities in the future, the need to use the third dimension of land, namely increasing the height of buildings and construction of multi-storey highways on the ground. Also, the creation of service roads and spaces such as subways and underground urban communication tunnels is felt in a tangible way. In Iran, the idea of ​​using intercity tunnels has been implemented since the beginning of this solar century. . But the study plan and the first phase of Tehran metro design was done in the early 50's by the French company "Sofroto". There are various methods in the implementation of guard structures for drilling tunnels, underground stations, mines and in general "underground structures" that the use of metal frames of the Austrian NATM in the construction of Tehran meters became common. But during 1984 and 1985, for the first time, concrete arches or ribs were used to reinforce the soil of the drilling site, which is known as the "Russian" method, and for the first time in the area of ​​Shemiran Gate Station by Dr. Sedghiani, Professor of Geotechnics, University of Tehran. Designed and executed by Kova Construction Company. This article is the result of the author's ten years of experience in various subway projects in Tehran and Karaj.