AIMS To study the relation between lung function decrease and cumulative exposure to dust and gases in tunnel construction workers. METHODS A total of 651 male construction workers (drill and blast workers, tunnel concrete workers, shotcreting operators, and tunnel boring machine workers) were followed up by spirometric measurements in 1989-2002 for an average of six years. Outdoor concrete w...

During the actual operation of full-face tunnel boring machine (TBM), vibration mainframe system is very strong, leading to failure key parts. Therefore, characteristics TBM Cutter head under maximum thrust condition are analyzed by ANSYS finite element software, and effects panel thickness, baseplate support plate thickness on analyzed. Subsequently, optimal solution obtained analyzing data wi...

As the main cutting tool of Tunnel Boring Machine (TBM) for rock-breaking, rock-breaking efficiency TBM disc cutters directly affects TBM’s boring speed, which in turn overall progress tunnelling project. Therefore, a simple and accurate evaluation method is an essential prerequisite to improve performance TBM. In this paper, classical force prediction equations were summarized applicability ea...

The development and extension of large cities induced a need for shallow tunnel in soft ground of building areas. Estimation of ground settlement caused by the tunnel excavation is important engineering point. In this paper, prediction of surface subsidence caused by tunneling in one section of seventh line of Tehran subway is considered. On the basis of studied geotechnical conditions of the r...