Port of Miami Tunnel Featured in Tunnels and Tunnelling

Port of Miami Tunnel Schematic from Tunnels and Tunnelling

The Port of Miami Tunnel project is featured in the December-January 2013 issue of Tunnels and Tunneling, the official publication of the Tunnelling Association of Canada. The article, entitled “U-Turn,” discusses the difficulties of turning the 12.8m-diameter TBM, nicknamed Harriet, around after breakthrough of the eastern bore on July 31, 2012. Geological and geotechnical issues are also discussed.

To read the article, visit the Tunnels and Tunnelling website.

For more information regarding this project, visit the GZ Port of Miami Tunnel page here.

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We’ve Moved!

GZ is excited to announce that we’ve moved our office location in London, U.K. We are now located in the AMP House on Dingwall Road in Croydon. We are thrilled to start the New Year in our new office while still providing the same exceptional services to our clients around the world. The address of our London office is:

Gall Zeidler Consultants-UK, Ltd.

AMP House, 4th Floor, Suite 7

Dingwall Road

Croydon, Surrey CR0 2LX

United Kingdom

Tel. +44-20-8123-9266

Please note that our telephone number for this office has not changed. You can view our new office location on our Locations page.

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Fourth Bore Construction Reaches Milestone

Tunnel Excavation Completed!

On September 21, 2012 – almost exactly two years from the start of tunneling – all excavation of the Fourth Bore was completed.

An update on tunnel progress with photographs and additional information can be downloaded (PDF) from

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Latest News – Caldecott Tunnel Excavation Completed

As of last week, the excavation of the new forth bore at the Caldecott Tunnel in Oalkand, California was completed.  The project is currently on track to open late 2013.

For more information, visit KGO-TV San Francisco, CA

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Dr. Gall presented at Breakthroughs in Tunneling 2012

September 21, 2012, Dr. Vojtech Gall presented “Case History: Tysons Corner Station and Tunnels”, at Breakthroughs in Tunneling 2012, on the campus of Colorado School of Mines in Golden, Colorado USA.

This Annual Tunneling Short Course gave attendees an opportunity to obtain CEU credits, learn from tunneling experts, and network with other tunneling professionals and industry leaders.

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Excavation for Caldecott Tunnel’s Fourth Bore Almost Complete

August 3, 2012 – The dig to begin the Caldecott Tunnel’s fourth bore will soon be complete outlining the giant passageway between Orinda and Oakland, California.  CALTRANS predicts by next week, the crew will finish up the nearly two year long project of excavation.

The fourth bore will add two lanes to the six-lane Highway 24 tunnel.  Still remaining is more than a year of concrete laying and other finishing work. The fourth bore is expected to open in late 2013 to relieve gridlock in one of the region’s most infamous bottlenecks.

For more on this project, visit

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Dr. Gall Presented at the 2012 NAT

Vojtech Gall, Ph.D., P.E., presented at the 2012 North American Tunneling Conference on “Real-Time Monitoring for Very Shallow Tunneling in Urban Settings”.

He also gave a Sequential Excavation Methods in Tunneling short course presentation entitled “Design and Construction of the Dulles Corridor Metrorail Project NATM Tunnels at Tysons Corner, Virginia”.

Subjects covered included: cements and admixtures, grouting equipment andpractices, chemical and cementitious permeation grouting, jet grouting, compaction grouting, pre-excavation grouting, backfill and contact grouting and cellular grouts.

The conference was held June 24-27, 2012 in Indianapolis, Indiana.

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Principal Kurt Zeidler, PhD, CEng Presents at the WTC 2012

GZ Principal Kurt Zeidler, PhD, CEng gave a presentation at the World Tunnel Congress May 18-23, 2012 in Bangkok, Thailand.

A copy of the paper presented by Dr. Zeidler, Making Space in Urban Areas, can be found here.

Dr. Zeidler also chaired the technical session, Long and Deep Tunnels.


Other topics discussed at the WTC included:

Urban tunnelling
Use of underground spaces
Natural disaster mitigation and management through underground space use
Underground structure resistance against seismic loads
Advance and innovation in mechanised tunnelling
Conventional tunnelling
Long and deep tunnelling
Contract practices, commercial aspects and risk assessment
Tunnelling nearby sensitive structures
Tunnel rehabilitation and restoration
Safety in tunnels
Micro tunnelling
Deep excavations


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Keynote Speaker, Vojtech Gall, Ph.D., P.E., Presents at AquaStop 2012

Dr. Gall presented “The Latest Strategy of Dry Tunnel Development” at AquaStop 2012.  The international conference was held May 29-30, 2012 in Saint-Petersburg, Russia.  The conference brought together waterproofing, roofing and heat-insulated specialists for the discussion of actual problems, trends and scientific research.


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GZ Finalist at International Tunnelling Awards

GZ Finalist at International Tunnelling Awards

Hong Kong, December 1, 2011 – GZ has been elected Finalist in the “International Tunnelling Project of the Year 2011” category with the Dulles Corridor Metrorail Project – Extension of Silver Line Metro to Dulles International Airport.

The twin NATM (New Austrian Tunneling Method) tunnels at Tysons Corner, as part of the Dulles Corridor Metrorail Project, serve as a good example of how close integration of tunnel design and construction management can accelerate a project and achieve a consistently high level of quality throughout all phases. This complex infrastructure project with the goal of making Dulles International Airport accessible to public transportation and connecting it directly to the heart of the District of Columbia posed a number of unique challenges: a dense urban setting, complex ground conditions (soft ground, groundwater table in tunnel cross-section, multiple settlement sensitive utilities directly above the tunnel), twin tunnels, shallow overburden with a busy six-lane highway crossing over the top of the tunnels, deep parking garage and multi story building next to alignment. GZ developed a tunneling method to meet this unique combination of challenges and minimize any impacts at the surface and sub-surface levels, optimize safety during construction, and cost in relation to effort and risk. The construction of the twin tunnels at Tysons Corner was scheduled on the critical path of the overall project program. Any delays in the construction of the tunnel segment would have had a major impact on the timely completion of Phase 1 of the project, thus making overall efficiency the primary goal. To reach this goal, a comprehensive risk mitigation strategy was put in place, and the GZ design team was integrated in the overall project. This integration and GZ’s hands-on involvement during the construction phase ensured optimal, time efficient solutions for the design, delivery, and approval processes. Ultimately, the initial tunnel design as well as the diligent management of the construction process resulted in the completion of this part of the project ahead of schedule and under budget, thus rendering any initial concerns regarding the tunneling segment as “stumbling block” for the whole project invalid. Another main factor in the overall success of the tunneling project was overall technical excellence. The integration of the latest technology in the design, such as the systematic installation of the steel pipe pre-support, using high precision drilling equipment and automatic pipe feeding ensured that the construction would be completed in as short of a timeframe as possible. The NATM tunnels at Tysons Corner earned an Excellence in Automation Award by the American Society of Civil Engineers (ASCE). The honor is awarded for processes, techniques, and actual cases that represent creative use of automation tools for civil engineers, lending further credibility to the superior design methods and meticulous execution of the Dulles Corridor Metrorail Project’s tunnel segment.

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