Gall Zeidler Consultants (GZ) is a worldwide leader in tunnel design, engineering, geotechnics, tunnel rehabilitation, and program and construction management. With over 300 miles of tunneling projects completed worldwide, our international team specialize in mastering difficult ground conditions by utilizing various methods, including dewatering, grouting and ground freezing. We also specialize in tunneling under shallow overburden and protection of neighboring structures by innovatively combining conventional (NATM/SCL/SEM) and mechanical (TBM) tunneling methods with ground improvement and state of the art waterproofing techniques. Our service portfolio ranges from conceptual and initial inception-level tasks—such as preparation of feasibility studies through development of tunnel designs and contractual documents—to construction management and site support services. GZ has been involved in many national and international projects, ranging from highway tunnel construction to transit tunnel projects, and some of our specialists frequently serve on expert review panels dedicated to the investigation and improvement of tunneling structures ranging from initial inception stages through final design development at the bid document level. Our company’s peer review services relate to a wide variety of facilities ranging from hydro-power systems in remote settings to complex transit structures at shallow depths in difficult, over-built urban areas. Design by Gall Zeidler Consultants does not stop at the drawing board. We provide construction support until the final product can be put to use.