Introduction:
As a Geo-structural Engineer deeply involved in the field of tunnel construction and soil mechanics, my recent webinar focused on an area of growing importance: the behavior of NATM (New Austrian Tunneling Method) tunnels in the porous clays of São Paulo. The rapid urbanization globally necessitates the expansion of underground spaces, and São Paulo's unique geotechnical conditions offer a rich study ground. This article, an extension of my webinar, aims to share key insights and research findings with engineering professionals worldwide on this global engineer knowledge-sharing platform.