Conferences and similar events were among the first casualties of the pandemic. They have been largely replaced – for the moment – by virtual events as an acceptable stop-gap, with their ‘lobbies’, presentations and webinars. And to a certain extent, they have various benefits and have been surprisingly successful, even when emulating keynotes, sessions, breakouts and more. But no matter how ‘immersive’ virtual events may be, they cannot provide the immediacy, lead capture and networking possibilities of the face-to-face interaction of a real-life event.

One effect of the pandemic may be that when conference calendars get back to a state of normality – which they will certainly – there could be a surge of attendances at physical events. But by the same token, a few conference organisers may feel that, for various reasons, virtual is the way to go, with some visitors preferring the travel cost savings rather than attend a venue packed with thousands of potentially infected people. These are unprecedented times and it will be interesting to see how the conference scene develops over the next 24 months.

BACK TO LIFE, BACK TO REALITY

It is a huge relief to hear – at least at the time this magazine went to press – that the Rapid Excavation and Tunneling Conference (RETC) 2021 is going ahead as a real, live event in Las Vegas, US on June 13-16. And what better place for a conference? It will provide a great opportunity to meet-up with colleagues and acquaintances, catch-up on projects, take in a few technical papers and enjoy a beer together – and even risk losing a few chips at the gaming tables.

The challenges of tunneling increase as tunnels get larger and deeper, while at the same time having to satisfy sometimes conflicting criteria, such as improved sustainability, faster advance rates and lower cost. Over the past 20 years, RETC has highlighted these issues and become one of the leading conferences for tunneling innovation and technology.

RETC is sponsored by the Society for Mining, Metallurgy & Exploration (SME). Held every two years, the event has become a magnet for practitioners, academics, contractors, and equipment and materials suppliers from around the world. The conference provides an opportunity to learn about the most recent advances and breakthroughs in tunneling, not to mention some of the latest products from leading tunnel industry suppliers.

At the time of writing, the RETC 2021 venue had not yet been confirmed but the event is scheduled for 13-16 June 2021 Below is a selective list of who will be exhibiting.

AGRU AMERICA
Booth 3627

At RETC, Agru will display a selection of its engineered thermoplastic polymer protection liners for various tunneling applications. This includes the Agruflex liner and the Easyfix system. Agru tunnel liners are made from high-grade resins and are formulated to provide high flexibility, good weldability, easy installation and a long service life.

In tunnel boring, cut-and-cover, and drill-and-blast applications, Agruflex liners are designed to protect the tunnel from infiltration of water, aggressive soils and root penetration. Water spots, dripstones made by lime diffusion and concrete corrosion are all claimed to be prevented by using Agru liners, thereby reducing maintenance and therefore the possibility of interruptions to the operation of tunnels.

The VLDPE polyolefin co-extruded liner is formulated to have good flexibility, allowing it to be well adjusted to the tunnel profile, an installation said to be easy and one which can provide leak-tight joints. The liner is attached to discs (fixed to the tunnel wall in a grid formation) either conventionally by hot gas welding or by using the Agru Easyfix (Velcro) system.

In the conventional way, the liners are joined by hot-wedge welding, with manual hot gas- and extrusion-welding used for patches and water-stop profiles. The discs act as a temporary fixing until concreting of the inner shell is completed.

With the Easyfix method, the discs are attached to the shotcreted lining using a Velcro system. The fabric-backed liner is attached to the tunnel, beginning at the tunnel floor, but the system allows subsequent adjustment if needed. With liner widths up to 4m, installation time savings of up to 40% are claimed to be possible. Headquartered in Austria, family-owned Agru also has a base in Georgetown SC. 

CREG
Booth 3522

CREG is one of China’s leading suppliers of tunnel boring machines of all types. The company offers a full-range of TBM solutions as part of its advanced technical programme aimed at satisfying project challenges and meeting customer expectations.

Up till June 2018, CREG had supplied 788 TBMs for tunneling projects, of which 656 are boring tunnels around the world. The company’s TBM range in boring diameters from 3m to 15m covers EPB, slurry, single- and telescope-shield, and gripper TBM types.

In addition to TBM tunneling solutions, CREG also has a wide spectrum of auxiliary tunneling equipment in its product portfolio, such as drilling jumbos, roadheaders, rolling stock, disc cutters, diesel- and battery-driven locomotives, as well as tunneling formwork and building structures. The company also has a subsidiary in Düsseldorf, Germany as a result of having acquired TBM-maker Aker Wirth in 2014.

Recently, a CREG 4.43m-diameter EPB TBM supplied to contractor HBK-Porr JV completed mining a 10.2km tunnel for the Doha Musaimeer Pumping Station and Outfall. With a 30m maximum tunnel overburden and extending below the sea bed, the TBM tackled an alignment comprising mainly Rus Formation, Midra shale and Simsima limestone. CREG’s bespoke TBM design included inactive articulation, shuttle-type shield, advance ground treatment, guidance system, special screw conveyor, modular design of pipeline and overall wear-resistance measures to improve safety and reliability. The machine was launched in February 2019 and completed its excavation exactly two years later, achieving best daily and monthly advances of 34.1m and 684.9m respectively.

COLORADO SCHOOL OF MINES (CSM)
Booth 3533

As one of the world’s leading centers for the education of tunneling and mining professionals, the Colorado School of Mines will highlight its numerous courses in underground construction. This will include the Underground Construction and Tunnel Engineering graduate program that runs at the Golden-based campus, and the new online Graduate Certificate program, as well as the full range of on-campus master, master’s non-thesis and PhD programs.

DR SAUER & PARTNERS CORP
Booth 3420

Dr Sauer & Partners will highlight a complete service for the design and construction management of tunnels, shafts and caverns and, in particular for the Sequential Excavation Method (SEM). The company says it provides specialist, innovative and cost-effective solutions for complex tunneling challenges that deliver real value to contractors and clients (and in most cases, the public who use the services). This might be for an underground urban environment where space is at a premium and for which a feasible solution must consider other service tunnels (e.g. metro, utilities, postal etc.) as well as building foundations.

The team at Dr Sauer & Partners says it not only works in a collaborative manner but brings varied disciplines together to provide better engagement across different service providers in order to deliver the expected result. This is said to produce a diverse and dynamic team focused on finding the best solution, and a claimed world-class standard across design, construction, as well as improved project delivery.

HERRENKNECHT TUNNELING SYSTEMS USA
Booth 3617

The Herrenknecht team – based in Sumner, WA, and with a Houston, TX service hub – will be on hand to provide targeted and project-specific support for the construction of underground infrastructure. Under the Herrenknecht Group umbrella, they will highlight the numerous integrated tunneling solutions with project-specific equipment and service packages.

Herrenknecht is an independent, family-run business delivering tunnel boring machines (TBMs) for all ground conditions and all diameters – ranging from 0.10 to 19m. The range includes tailor-made machines for traffic, supply and disposal tunnels, technologies for pipeline installation, as well as drilling equipment for vertical and inclined shafts, and deep drilling rigs.

Efficient supply and disposal systems are the indispensable arteries of cities. Throughout the US, Herrenknecht small- and large-diameter tunneling equipment is used for new water, sewage, CSO and stormwater tunnels. In public transport applications, the area of focus at RETC will be on metro expansion in Los Angeles. The contractors had to prepare for possible gas deposits, choosing specially configurated TBMs which included explosion-proof components, extra-large ventilation systems, and gas sensors integrated into an overall safety concept. For road tunnels, extra-large diameter TBMs are being prepared, such as for the Chesapeake Bay and Hampton Roads tunnels. In microtunneling and pipeline installation, construction companies together with Herrenknecht are pushing forward with significant technological developments. This includes carrying out complex projects along curves or installing pipelines in heterogenous, water-permeable soils. With E-Power Pipe it is now possible to realise very small diameters with ten times greater lengths (over 1,000m), says Herrenknecht.

ROBBINS
Booth 3508

Robbins is one of the world’s foremost developers and manufacturers of advanced, underground construction machinery. As a total supply company, the various Robbins solutions offer customised tunnel boring machines, conveyors, cutters and more, backed up by knowledgeable field service personnel and technical support.

The range of services provided by Robbins ranges from machine planning and start-up to breakthrough and beyond. Visitors to RETC can find the latest information on the company’s underground projects and products. The booth will be staffed by a team of knowledgeable personnel with decades of experience in the tunneling industry.

TERRATEC
Booth 3404

Incorporated in 1990, Terratec is a world-renowned Australian designer and manufacturer of tunnel boring machines, microtunneling systems, raise-boring machines, conveyor systems and other custom-made products for tunneling and mining applications. Terratec has delivered tunnel boring machines and TBM parts in North America since 1992. Over the past 25 years, the company has had several raiseboring machines working in mines across both the USA and Canada.