A Review Study on Methods of Tunneling in Hard Rocks

This article presents a review on the different methodologies that are used for tunnels excavations in hard rocks in present era. Growing needs for modern transportation and utility networks have increased the demand for a more extensive and elaborate use of underground space or through high mountains / hills. As a result, more projects have to be completed in various ground conditions and one of which is more challenging is to carry out excavation work in hard rocks. Significant technological advances have rendered these projects possible, but have also given rise to new challenges as many of these projects have to be completed in difficult conditions, with very strict environmental constraints, particularly in urban areas where the potential impact of tunneling on existing structures is a major concern. This paper addresses the main aspects of tunneling and underground works performed in hard rocks. A summary is presented of the more recent advances and widely adopted techniques in these regards.