Actual performance analysis of a double shield TBM through sedimentary and low to medium grade metamorphic rocks of Ghomrood water conveyance tunnel project (lots 3 and 4)

In this paper, after a brief description of engineering geological properties of Ghomrood water conveyance tunnel project (lots 3 and 4 with a total length of 18 km), the actual performance of the machine during the excavation of tunnel through sedimentary and low to medium grade metamorphic rocks has been analyzed. Subsequently, using data collected during pre-construction and construction phases of the project, the relationships between rock mass properties and measured machine performance parameters have been investigated and proposed as a prediction model which can be used in future projects in which similar geological conditions are encountered. Results of analyses indicated that there are strong relationships between TBM performance and engineering geological conditions of the tunnel alignment.

Automated summary

This paper analyzes the performance of a machine in excavating tunnels through sedimentary and low to medium grade metamorphic rocks in the Ghomrood water conveyance tunnel project. It proposes a prediction model based on the relationships between rock mass properties and machine performance parameters for future projects with similar geological conditions. Results show strong correlations between TBM performance and engineering geological conditions.