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By Philippe Dumont

Presentation of the project Underground civil works to be performed They include two single track running tunnels and a service tunnel of a length of fifty kilometers . Many cross adits (180 adits) : to link the tunnels (53 cross passages), to relieve air super pressure from one tunnel to the other (87 piston ducts), to install technical adits (40 electrical rooms). Two cross-overs located at one third of the whole length, allow trains to shunt from one tunnel to the other so as to ensure one way traffic in case of emergency. Pumping stations allow water to be collected at the lowest point and pumped out. 1 Main features of the tunnels 1.1 The service tunnel This 4.8 m inner diameter gallery allows During civil works - front probing operations of the geological layers encountered (front and vertical probes). - lateral soil grouting that may be necessary to facilitate the boring of the two running tunnels . During operations - Maintenance and safety vehicles traffic - Fresh air supply to running tunnels - Fire protection and drainage system - Electricity supply and control and communication. The service tunnel has been bored with a 5.72 meter external diameter Robbins TBM for the undersea section, and a MITSUBISHI TBM for the land section.

Jan 1, 1991

By Hans W. Brodbeck

The Advisory Conference on Tunnelling of the OECD, held in Washington, D.C. in June 1970, has established the following definition: "Tunnelling refers to the construction by any method of a covered cavity of predesigned geometry whose final location and use are under the surface, whose cross-sectional area is greater than 2 square metres". (1) The definition makes clear that the term includes all types of underground construction, be it in hard rock, soft ground, under mixed conditions, underwater, etc. Small-sized tunnels in rock therefore constitute but one part of the tunnelling scene. With an ever-growing urbanisation taking place in industrialized as well as developing countries, the demand for small-sized tunnels is, however, rapidly increasing and requires a far-reaching mechanization of excavation and support functions. This trend is accentuated by the fact that small-sized tunnels are far more labor-intensive than large ones, and, with wages raising at a much faster rate than costs for plant and equipment, this will accelerate the introduction of new tunnelling systems. SMALL-SIZED ROCK TUNNELS The main field of application for a tunnelling system for small sized hardrock bores is thus defined. It is in fact the numerous relatively short tunnels required under cities and other populated

Jan 1, 1974

By Harry R. Price, Keith M. Swaffar

The Northeast Raw Water Tunnel transports untreated water to the Detroit Water and Sewerage Department's (DWSD) Northeast Water Plant where it is treated and distributed. The occurrence of a subsidence area which was attributed to the tunnel prompted the DWSD to have the tunnel investigated. After an extensive historical and geotechnical investigation, two access shafts were constructed along the alignment in the vicinity of the subsidence. Following completion of the shafts, the subsidence area was inspected in the wet prior to dewatering the tunnel. Upon the completion of dewatering, a dry inspection was performed. During the dry inspection, an area of significant distress was encountered where sand and silt were boiling into the tunnel along with large volumes of groundwater. This distressed area was located 800m (1/2 mile) north of the original subsidence area. The tunnel was immediately refilled with water and an emergency repair program was planned and implemented. As a result of the distressed nature of the secondary tunnel liner, dewatering of the tunnel could not be performed until the secondary liner and the surrounding soils were stabilized. This paper presents a case history of both the investigation and the repairs of the Northeast Raw Water Tunnel including the various grouting and unique tunnel stabilization methodologies which were utilized.

Jan 1, 1987

By Tim Cleary, Steve Skelhorn

The 9th Line / 16th Ave tunnels are part of a $700 million expansion of the York Durham Sewage System, north of Toronto. The 15 km of tunnels presented many challenges, including glacial and postglacial deposits, at depths up to 55 m. Due to high hydrostatic heads, the Owner specified EPB tunnelling, however, an alternate was proposed utilising rib and lagging tunnels, combined with a de-watering scheme. State of the art technology was utilised with a new Lovat TBM, incorporating PLC control, soft start water-cooled motors and a head designed to tackle the mixed ground expected. The 9th Line tunnels were completed in 2002. Subsequently the second section of tunnel along 16th Avenue has been awarded to the Joint Venture. This paper presents a case history of the soft ground tunnelling, including design elements, tunnel systems and TBM operations.

Jan 1, 2003

By Penglu Gan, Jinjie Zou, Chenglang Pan, Xiaowu Tang, Yu Zhao

"The north segment of the Zizhi Tunnel that consists of twin tunnels was excavated at a shallow depth in soft ground using the Shallow Tunneling Method. Based on continuous field measurements, the development histories of surface settlement were analyzed first. The observed development process could be roughly divided into three stages and the influence of river was evidenced. Transverse and longitudinal surface settlements above the twin tunnels were then fitted with empirical models. The obtained trough width parameters in transverse and longitudinal direction (it and il) and the volume loss (VLs) were presented and discussed. Additionally, surface settlement was compared with the crown settlement. The relationship between surface and crown settlement behaved in two different ways inside and outside the river-affected region. The findings in this project give references for predicting surface settlements in similar tunneling condition. INTRODUCTION Nowadays tunnel construction has become a major way of utilizing underground space in many large cities. The ground deformation will be inevitably induced in the tunneling process. Engineers should always be careful about excessive deformation that may damage adjacent structures. For shallow tunnels, controlling ground deformation turns to be more risky. Since soil arching is not completely formed in the shallow tunneling, settlements can easily develop from tunnel crown to ground surface.A conventional tunneling method named Shallow Tunneling Method (STM) has been developed and widely applied to constructed shallow tunnels in China. The major difference between this method and the New Austrian Tunneling Method (NATM) is whether considering self-supporting capacity of surrounding ground or not. In order to reduce the disturbance of surrounding soils, several guidelines are highlighted in this method, including advanced pipe forepoles, strict grouting, short excavation length, strong support, quick closure and frequent measurements (Fang 2012). Nevertheless, the ground deformation is still hard to control and becomes a concerned problem, mainly because ground settlement has some regional features and largely depends on the detailed excavation methods (bench cut method, multiple heading method, etc.) and ground condition (sand, clay, decomposed rock, etc.)."

Jan 1, 2016

By Will Foreman, Douglas D. McLearie, Edwin K. H. Tong, William H. Hansmire

Hong Kong’s Strategic Sewage Disposal Scheme (SSDS) Stage I involves the provision of a system of deep tunnels for transporting to a central treatment works wastewater collected from a number of catchments around Victoria Harbour. For the SSDS Stage I works, about 24 km of tunnels have been excavated in hard rock at depths ranging from about 80 to 150 m below Victoria Harbour and the surrounding heavily developed areas of Kowloon and Hong Kong. Five tunnel boring machines(TBMs) with diameters ranging from 3.2 m to 4.3 m were used to excavate the tunnels. Tunnel excavation has been completed and tunnel linings are in progress. Major tunnelling issues such as ground stabilisation and water control encountered in the project are summarised. An overview of one of the possible future tunnel systems that might be adopted in subsequent stages of SSDS is also presented.

Jan 1, 2001

By Dean Brox

The Galore Creek Mine project is one of the newest major mining projects under development in Canada. The project is located in a very remote area of northwestern British Columbia and is being developed by NovaGold Resources and Teck-Cominco of Vancouver. The mine project comprises one of the largest and highest grade undeveloped porphyry-related gold-silver-copper deposits in North America. In order to access the mine site a new 120 km road is required including a 4.4 km mine access road tunnel. Glaciers with heavy snow pack cover approximately two-thirds of the tunnel alignment with a maximum cover of 1200 m. The size of the access road tunnel is about 50 m2 and has been designed as a large single lane road tunnel to accommodate the transport of large size mining equipment for mine start up and ongoing operations. The rock conditions along the tunnel alignment comprise very strong volcanic rocks. Key services for mining operations will be incorporated into the tunnel comprising diesel and power as well as the concentrate pipe-line. Structural portal canopies and portal houses have been incorporated into the tunnel design due to the risk of rockfalls and avalanches in the portal areas. The mine access road tunnel is a significant and critical-path component to the overall project to provide vehicular access to allow construction of the mine site. In order to meet the expected mine start up date the construction of the tunnel works have commenced prior to any other works at the mine site and will be constructed entirely by helicopter support. The tunnel works commenced in the summer of 2006 with the advanced excavation of the overburden materials at the portals. Tunnel construction from the North portal commenced in the spring of 2007. When completed, the mine access tunnel will be the longest private road tunnel in North America. The key design and constructability issues for the mine access road tunnel project are presented and discussed along with a construction status update as of late 2007.

Jan 1, 2008

By Rajni Patel, John McDonald, Steve Dubnewych, Michael McKenna

The Upper Reach segment of the Northeast Interceptor Sewer (NEIS) is a3.2-km-long tunnel excavated in interbedded marine sedimentary deposits with approximately 40 m of cover. The tunnel was initially classified by Cal/OSHA as “potentially gassy.” During excavation, high levels of hydrogen sulfide and methane were encountered, prompting Cal/OSHA to reclassify the tunnel as “gassy.” In addition, the tunnel excavation encountered an abandoned, 100-year-old water tunnel known as the “Narrows Gallery.” This existing tunnel was completely full of water and under 30 m of hydrostatic head. This paper will discuss the unanticipated difficulties and design solutions implemented to construct a gassy tunnel exposed to high volumes of water.

Jan 1, 2005

By Peter Johnson, David Barber, Lachlan Henderson

"The traditional approach to rail tunnel fire safety design is to follow NFPA 130, which assumes a major tunnel fire could occur and requires bi-directional emergency ventilation. There is no regard to the impact of ventilation on fire growth and smoke production. In Europe and other parts of the world, the need for tunnel ventilation systems to provide smoke management in the event of fire is being questioned. The European Commission’s Safety in Railway Tunnels TSI is based on a philosophy that improved running capability (preventing fires and other events stopping the train in the tunnel) and elevated fire performance of materials means the chances of a major fire in a tunnel is highly unlikely, with only small fires expected, and no tunnel ventilation required. This approach is reinforced by the International Tunneling Association which has recently published an Engineering Methodology for Performance Based Fire Safety Design on Underground Rail Systems, which includes a methodology that does not require assessment of tenability in tunnels, but requires a scenario based risk assessment to be undertaken to determine overall fire safety measures. Recent research by the University of Edinburgh has shown that forced airflow from a mechanical ventilation system may promote fire growth and increase smoke volumes much more than with natural ventilation. Whilst the concept of no mechanical ventilation (i.e. natural ventilation) is a new concept for some, for many rail tunnels it is worthy of serious further consideration. RAIL TUNNEL SMOKE MANAGEMENT AND STANDARDS Smoke management using mechanical bi-directional ventilation systems has been a central part of the fire safety design solution under NFPA 130 for rail tunnels since 1982. The current version of the standard, NFPA 130: 2014, states that mechanical ventilation should be fitted to rail tunnels of length greater than 305 meters and an engineering analysis should be undertaken for tunnels of length 61 to 305 meters to determine whether mechanical ventilation should be fitted. However, this approach is not necessarily reflected elsewhere in the world. In Europe in particular, mechanical ventilation systems for smoke control within rail tunnels have taken a much less central role within the standards framework."

Jan 1, 2016

By Leon Maday, Dan L. Pecha, Jeremy Johnson, Daniel N. Adams

The Brightwater conveyance system includes 26 km of tunnels, a 130 mgd pump station, 2 km of micro tunnels, and a 2.4 km outfall. The tunnels extend from Woodinville to Puget Sound through varying soils in 1 to 7 bars of hydrostatic pressure and depths to 185 m. The tunnel diameters range from 4 to 6 m and include numerous lining systems. This paper highlights major shaft and tunnel design, including dual cellshafts, multiple pipe configuration tunnels, polymer concrete segments, and the use of a one pass lining designed to convey high pressure effluent.

Jan 1, 2005

By Nasri Munfah, Raymond E. Sandiford

"Superstorm Sandy (Sandy) created a storm surge that inundating many of the tunnels that pass beneath the Hudson and East Rivers. The tunnels are vital infrastructure links for the economy of New York City and the northeast region. The sea water, which contains highly reactive salts, caused significant damage to electrical and mechanical systems. In addition, the salt water inundation left corrosive precipitants on the tunnel linings and on and within electrical duck banks. After the salt water was evacuated from the tunnels, condition assessments were performed using a state of the art approach involving high resolution laser scanning, digital imaging, and thermal imaging. These scans were performed prior to hands on inspections. The damage assessment concluded that, although the tunnel structural linings were not damaged, the interior elements of the tunnels needed major rehabilitation to arrest the continual deterioration of the structures. This paper details the state of the art approach used for these tunnel inspections. INTRODUCTION On October 29, 2012 Super Storm Sandy flooded a large number of both transit and vehicular tunnels in the New York Metropolitan area. The region’s transportation network was severely disrupted. The storm damage is estimated to have been in excess of $30 billion, and with the tunnels out of service, the local economy was losing hundreds of millions in economic activity. Restoration of these tunnels was a very high priority and the resulting expedited restoration process did not always provide adequate time for comprehensive condition surveys. This resulted in many of these surveys being conducted after service restoration. Inspecting highly trafficked transit tunnels is challenging and the logistics of working in short night outages led to a rethinking of the conventional inspection approach. Traditionally, visual and tactile methods are first used to inspect tunnels and then quite often followed by LiDAR (Light Detection and Ranging) scanning and perhaps infra-red scanning. For multi-mile tunnels, the time required to visually map tunnel features can be quite extensive. By performing the scanning first and then performing the visual and tactile inspections, one is able to use the scan data to identify the specific areas that need detailed inspections. This approach was used quite successfully for a number of the NYC tunnels."

Jan 1, 2016

By Mohamed A. Younis, Paul J. Headland, Paul H. Madsen, Vojtech Gall

INTRODUCTION A 100 ft long, 20 ft high and 18 ft wide NATM tunnel was excavated through grouted clean sands beneath a busy city street, including a variety of existing utility lines. The new tunnel associated with a hospital expansion will serve as a pedestrian tunnel connecting a parking structure with a new hospital facility. Tunnel construction started on December 15, 2005 when drilling for the grouting program started and was completed on May 26, 2006 when the tunnel final lining was completed. The tunnel was constructed by Kiewit Construction Company as a tunnel subcontractor to The Christman Company who is constructing the hospital facility for Spectrum Health in Grand Rapids, Michigan. URS was the project designer. GallZeidler Consultants, LLC were the contractor’s NATM consultant. PROJECT DESCRIPTION The Michigan Street Pedestrian Tunnel is a component of the Michigan Street Development located along the north side of Michigan Street NE between Coit Avenue NE and North Division Avenue in the downtown area of the Grand Rapids, Michigan. The Michigan Street Development includes a parking deck and four new towers to be constructed over the proposed parking deck. The tower planned furthest east is being developed by Spectrum Health as the Lemmen-Holton Cancer Pavillion. The purpose of the pedestrian tunnel is to connect the proposed Lemmen-Holton Cancer Pavillion with the future Spectrum building to be located on the south side of Michigan Street NE. The southern end of the tunnel was constructed with a bulkhead until the future Spectrum building is constructed at which time interconnection will be required. The tunnel site plan and profile are shown in Figure 1, Site Plan, and Figure 2, Tunnel Profile. Several challenges were faced during the design and construction of the Michigan Street Pedestrian Tunnel. These challenges included compressed design and construction schedule, maintenance of traffic and protection of old underground utilities. The tunnel was being constructed as part of the Michigan Street Development and coordination with other concurrent construction activities was required. The tunnel was constructed within a specified window of time to allow other associated construction activities to take place without compromising the overall project schedule. The design started in June 2005 and construction was completed by June 2006.

Jan 1, 2007

By Andy Mille

The paper highlights development of tunneling methodology in the UK during the years 1990-2000 using the example of two major tunneling contracts where there solution of difficult tunneling problems during construction has benefited the industry as a whole. The paper deals with specific difficulties on two Contracts. The London Water Ring Main 80 kms (50 miles) long tunnel average internal diameter 2.54 m (9 ft4 in) and the Brighton Stormwater Tunnel 5.2 km (3.2 miles) long tunnel with an internal diameter of 6 m (19 ft 8 in). The results of human endeavour and technological innovations will demonstrate the giant strides made in tunneling methodology in the last decade of the 20th Century.

Jan 1, 2001

By David Mast, Irwan Halim, Brian Hagan, Kaveh Talebi, Jason Edberg, Amanda Foote

On June 14, 2023 Jay Dee Contractors’ Tunnel Boring Machine (TBM) “Phoenix” holed through and completed mining the second drive of the I-75 Segment 3 Storage and Drainage Tunnel. Completion of the tunnel came only after overcoming several challenges, including a groundwater intrusion event which deposited thousands of cubic yards of wet ground material into the tunnel. This paper will discuss the events which delayed completion of the tunnel by over nine months, the risk management and construction approaches assumed by the Design-Build team during bid, several challenges faced by Design-Build teams when building stormwater resilience tunnels using traditional Department of Transportation standards, and recommendations for improving risk allocation and proposal documents for future similar Design-Build tunnel projects.

Jun 23, 2024

By Joan Carles Casado Ortega, Mitchell Gerdtau, Sandeep Pyakurel, Eric Crocker, Frank Perrone

The Parallel Thimble Shoal Tunnel (PTST) project is a part of the Chesapeake Bay Bridge- Tunnel (CBBT) complex. The project involves the construction of a two-lane bored tunnel under the Thimble Shoal Channel between Portal Island #1 (the southernmost island) and Portal Island #2. The new PTST will be the rst transportation tunnel constructed in the Mid-Atlantic region by a tunnel boring machine (TBM). This paper describes the design and construction of the tunnel approach structure in an open marine environment with the strategies employed to overcome the various construction challenges. The project is unique since the entire tunnel approach structure is built on a very limited area within an open marine environment without any reclamation of the existing island.

Jun 23, 2024

By Ryan P. Sullivan, Ben D. DiFiore, Robert J. Auber, Michael A. Piepenburg, Lisa M. Smiley

Pollution to Lake Erie will be significantly reduced by the Westerly Storage Tunnel (WST) system, which is mainly comprised of a 10,000-ft long tunnel and a dewatering pump station in the downstream tunnel shaft. Separate construction contracts for the tunnel and pump station required careful management of the interface risks. A key decision was to decouple the projects by relocating the mining shaft away from the pump station. The need to receive the tunnel boring machine (TBM) in the pump station shaft was eliminated by dismantling the 28-ft diameter TBM in the tunnel then carrying it back through the tunnel and up the mining shaft. This paper discusses how interface risks were successfully managed during design and construction to limit overall schedule impacts.

Dec 1, 2022

By Carlos A. Jaramillo, Seng Hing Ngu

"The Murum Hydroelectric Project is a 944-MW development consisting of a 145 meter high RCC dam, two 2660 meter long, 9 meter excavated diameter upper pressure tunnels, surge shafts, two 950 meter long 7 even meter OD penstock tunnels and a surface powerhouse. The project is located in the eastern section of the State of Sarawak, Malaysia, about 200 kilometer from Bintulu, in the Rajang Fold-Thrust Belt, an Upper Cretaceous to Upper Eocene fold and thrust belt that extends under most of Sarawak. The Belaga Formation consists of a thick sequence of deep marine sediments currently appearing as steeply dipping strata of thin to thick bedded, fine to medium grained sandstone interbedded with argillaceous rocks, resulting on a “Flysch” type geologic environment. The project pressure tunnels were excavated perpendicularly to these strata resulting on frequent change on rock conditions and behavior, and required rock support. This paper describes the characterization of the rock mass, design of rock support, and incidents during construction. Particularly interesting were convergence issues in Tunnel 1 resulting from Tunnel 2 excavation. INTRODUCTION The Murum Hydroelectric Project is located in the eastern section of the State of Sarawak, Malaysia, about 200 kilometers from Bintulu, and upstream of the Bakun Hydroelectric Project. The project consists of a 145 meter high RCC dam, a 50 meter high intake tower, two nine meter OD and 2660 meter long upper pressure tunnels, two nine meter OD and 175 meter long vertical shafts, two 25 meter diameter and 80 meter deep surge tanks, two seven meter OD and 950 meter long penstock tunnels and four seven meter OD and 50 meter long branch tunnels, two 8 meter diameter to 3.4 meter diameter and 1400 meter long penstocks installed within the shafts, penstock tunnels and branch tunnels ending in a powerhouse with 944 MW installed capacity. LAYOUT OF THE WATERWAY TUNNELS The two waterways tunnels are basically parallel as shown in Figure 1, with each tunnel supplying water to two units in the powerhouse. The tunnels start separated 25 meters center to center, but 250 meter from the intake the separation increases to 35 meters. The tunnels are lined with reinforced concrete until they reach the surge shafts and steel lined from there to the powerhouse. The tunnel profile is shown in Figure 2."

Jan 1, 2016

By Stephen J. Navin, Francis P. D. Navin

Long-distance movement of various materials by conveyor is becoming common; therefore, it is no surprise that conveyors are frequently found in very long tunnels. In such long tunnels, there is a continual controversy between the tunnel operator's requirement for a maximum of clear space for the conveyor and vehicles and the investor's wish to make the minimum capital investment for excavation. This analysis shows that the question becomes more pressing as the tunnel becomes longer. The result given in this paper is a straightforward method by which an economic and operational optimal tunnel width may be selected for any specified tunnel length. Detailed computational formulas are developed relating costs of construction, vehicle operation, vehicle accidents, and conveyor downtime to both tunnel width and length.

Jan 1, 1985

By Steve Kral

In December 2013, the Colorado Department of Transportation (CDOT) completed the widening of the eastbound tunnel on Interstate 70 (I-70) from two lanes to three. Work on the westbound tunnel began earlier this year and is scheduled for completion in December. The Twin Tunnels project is located in the mountains about 55 km (35 miles) west of Denver. They were bored during the 1960s when I-70 was being built and became the main access to Colorado?s growing number of ski areas and the state?s Western Slope. Throughout the decades following their construction, traffic on I-70 continued to increase and now the tunnels have a major bottleneck. Com-mutes to and from the mountain resorts, particularly on weekends, have become long and slow. Adding a third lane through the tunnels will help alleviate the congestion. (A complete report on the project can be found in T&UC, December 2013, page 61.) Once the eastbound tunnel was completed late last year, CDOT authorized the funding to begin work on the westbound side. That made economic sense, as the equipment used on the eastbound tunnel needed to only be shifted across I-70 to begin work on the westbound side, rather than removing it in December and bringing it back in March when construction began on the westbound tunnel. Work on the westbound tunnel uses essentially the methods that were used on the eastbound tunnel ? removal of the existing concrete lining and using drill-and-blast methods for tunneling widening. The main difference between the two tunnels is that the westbound side requires more blasting on both ends to widen I-70 to three lanes.

By Jun Ho Lee, Dae Young Kim, Ebrahim Farrokh, Ki Chang Hyun

"The Jinhae Geoje gas pipeline tunnel project is the largest (7.8 km) and the deepest (90 m) subsea tunnel in South Korea. This tunnel will house a pipeline to carry natural gas from the mainland to Geoje Island southeast of the country to alleviate the increased demands for natural gas, especially in the winter season. Tunneling is currently underway using two slurry shield TBMs of 3.5 m diameter. This paper describes the major design elements of the tunneling machines and their performance evaluation. For this purpose, a thorough analysis of geotechnical information was performed to evaluate the tunnel elevation to reduce the risk of tunneling under high water pressure in unstable and permeable rock mass under 9 bar water pressure. TBM specification and TBM performance were also analyzed using different methods, including well-known models as well as a rotary cutting machine test developed in house in Hyundai Engineering and Construction Company. INTRODUCTION High demand for natural gas, especially in winter season was the primary driving factor for the design of the Jinhae Geoje gas pipeline project. This project is located southeast of South Korea between Jinhae district and Geoje Island and runs for over 50 km length. The mid part of this project includes a 3.5 m diameter subsea tunnel consisting of two sections of Geoje to Jiri Island (4.3 km) and Jinhae to Jiri Island (3.5 km). Figure 1 shows the tunnel project location and its layout. Figure 2 shows the geological profile along the tunnel. As can be seen, the tunnel passes mainly through three rock types: granite, tuff breccia, and andesite tuff. This tunnel was planned to be constructed by two face pressurized shielded TBMs and to be lined with a segmental lining of 2.8 m internal diameter. The major challenge for this tunnel is its maximum expected water pressure at the tunnel invert (8.83 bar). At such a high water pressure, the TBMs required special design to ensure they can handle unexpected water pressure and to ensure the risks for the TBM maintenance intervention are minimal. In this regard, a thorough analysis was conducted on the TBM design parameters and geotechnical information to define required TBMs’ design parameters and to identify the safest tunnel elevation. This paper provides a brief overview of the project geotechnical information, TBM selection and its design specification, tunnel elevation selection, and TBM penetration rate evaluation. In this regard, a rotary cutting machine testing equipment was used to perform trial tests on a similar rock type encountered along the tunnel for performance evaluation and optimization."

Jan 1, 2016