Abstract:  In the past two decades, tunnel engineering has achieved unprecedented development with a steady increase in infrastructure construction. In this study, a statistic based analysis of the academic journals between the years 2001 to 2020, which are included in CNKI, is conducted using the document visualization software VOSviewer. Information such as the number of documents published, and popular keywords used in recent years are analyzed, and a structural map of keywords and author institutions is constructed. The results indicate the following: (1) The number of documents published in the field of tunnel engineering has consistently increased over the last 20 years and has roughly experienced three stages, i.e., slow growth, stable growth, and rapid development. (2) Most studies in the field of tunnel engineering research are in the form of research teams. Some researchers in the team usually publish more papers, and these researchers are generally at the core of each research team. (3) The results of visual cluster analysis indicate that the research hotspots in the field of tunnel engineering are mainly concentrated in certain research directions such as construction technology, special geotechnical and unfavorable geology, stability analysis, tunnel type, risk control, and dynamic analysis. (4) Additionally, highprecision exploration, mechanized construction, tunnel waterproofing and drainage system, lining structure cracking, adverse geological disaster prediction, and intelligent construction will become new future avenues of research.

Key words:
tunnel engineering, VOSviewer, bibliometric analysis; visual network, research hotspot