**1. Introduction**

The problem of rock mechanics and engineering is an old and new subject encountered by human beings in their struggle with nature for survival and development. To call it ancient means that it has a long history, whereas calling it brand new refers to the continuous emergence of new problems and new situations in engineering practice, which is quite challenging. With the deepening of human engineering activities, the problems of rock engineering are becoming more and more prominent, and the problems encountered are becoming more and more complex. In the practice of solving complex rock engineering, human beings have summarized many topics that are difficult to explain or solve with classical mechanics.

In order to form a unified understanding of the problems and advanced solutions in complex rock engineering, experts at home and abroad have been able to actively deliver the latest research results to this Special Issue. The Special Issue focusses on advances and innovative research on rock mechanics and rock engineering, and provides a showcase of recent developments and advances in rock mechanics and innovative applications in rock engineering. Since the launch of the Special Issue, a total of 15 well-known scholars have submitted their research work to this Special Issue. After strict quality screening, five high-level papers have been published in the *Energies* journal.
