Gall Zeidler Consultants (GZ) is proud to announce the publication of the International Tunnelling and Underground Space Association’s ITA Report No. 39, “Guidelines for the Design and Construction of Conventional Tunnelling in Urban Setting.” The guideline was developed by ITA Working Group 19 – Conventional Tunnelling and published as part of the 2026 World Tunnel Congress Conference Proceedings, held from May 17–21, 2026, in Montreal, Canada.

GZ is honored to have played a leading role in the development of this important industry guideline. The report was prepared under the leadership of Nasri Munfah, GZ’s Principal, during his tenure as Animateur of ITA Working Group 19. Several members of the international tunnelling community contributed to the report, including Nasri Munfah and Dr. Vojtech Gall of GZ.

The guideline addresses the design and construction of conventional tunnelling in urban environments, including methods such as NATM, SEM, and SCL. It provides recommendations for the safe and efficient delivery of complex underground structures in dense urban areas, where tunnelling must account for challenging ground conditions, groundwater, low cover, existing utilities, sensitive structures, and the need to minimize impacts on streets, traffic, businesses, and the public.

By helping advance this international guideline, Gall Zeidler Consultants continues its longstanding commitment to delivering safe, sustainable, and resilient underground infrastructure.

Download the guideline on our website via this link and explore other publications authored by the GZ team. Copyright of the Tunnelling Guidelines held by the International Tunnelling and Underground Space Association (ITA).

Photo featuring members of WG-19, including Nasri Munfah, GZ Principal, Vojtech Gall, GZ Principal, at the WTC 2026 in Montreal.