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By G. Adderley, A. Wetherelt

The problems of poor drilling in underground operations have been highlighted on many occasions. Incorrect collaring and poor angular deviation can all lead to an increased block size, dilution, over-break adding to both cost and time, while in a tunnelling operation sidewall damage and a poor percentage pull from a blasted round has similar consequences. This paper sets out to further investigate the ability of the laser scanner method of obtaining drill hole deviations and collaring errors at the face as described by Wetherelt and Williams (2006). Tests were carried out to compare measured inter-hole burdens from this method in comparison to that obtained using a total station survey. To investigate the ability of these methods to accurately determine drilling errors, a field test was carried out through an analysis of a series of pre-drilled blast holes of known inclination and direction. A time-motion study was also conducted for a varied number of holes to assess the usability of each method. In line with current research into blast vibration being undertaken at the Camborne School of Mines, 6 cut blasts were carried out to establish the effect of poor drilling on a blasts success to see whether an increased burden at the toe of a hole had an influence on vibration.

Jan 1, 2009

By Clayr Alexander

Stillwater Mining Co. (SMC) is engaged in developing, extracting, processing and refining palladium, platinum and associated metals (PGM)from the J-M Reef. This geological formation is located in Stillwater, Sweet Grass and Park counties in southern Montana. Associated byproduct metals include rhodium, gold, silver, nickel and copper. SMC’s current mining operations are near Nye, MT. The company is currently developing a second underground palladium and platinum mine, the East Boulder project, about 21 km (13 miles) west of the Nye operations. A 5,650-m (18,550-ft) tunnel is required to gain access to the ore-bearing horizon (J-M Reef).

Jan 1, 1999

By Martin Herrenknecht

Tunnel boring machine (TBM) development continues to take on not only larger diameters, but also more difficult ground conditions. Ground conditions consisting of unstable faces with water pressures up to 15 bar have required innovative design approaches. A systems approach has been required to produce tunneling machines that can safely excavate the tunnel in an efficient, cost-effective manner that stresses production and labor saving approaches. This article reviews the current design developments and present recent projects where these most recent principles have been applied. The world?s growing population and rapidly proceeding urbanization are boosting an enormous demand for new and high-capacity infrastructures to secure the mobility of goods and people. Densely populated areas face the challenge of providing efficient traffic infrastructure such as a modern public transport system. At the same time, the maintenance and modernization of supply and disposal structures for water, sewage, energy and communication are essential. Last but not least, are supra-regional transportation routes such as long distance water diversion schemes. All of these projects are as demanding and are characterized by a tight time schedule. In this context, the demand for efficient tunnels for traffic and utility lines is increasing, as new infrastructures often leads underground because of limited space above ground. Also, tunnels are the obvious choice to cross natural barriers like mountain ranges. To handle the complex and variable geological conditions and other constraints, such as low overburden, high water pressure or long tunnel drives while facing increasing demand of a quick completion of a project, mechanized tunneling sets standards regarding safety, profitability and environmental protection in traffic tunneling projects as well as in the trenchless construction of utility tunnels. Different machine types and working principles have been developed to master various geological and hydrogeological requirements. Continuous activity in research and development leads to constant improvement of the mechanized tunneling process.

Jan 1, 2008

By Gary Brieley

Until well into the 20th century, most construction work was performed under the auspices of a master builder or in a manner that would be described today as design-build. In addition, many civil engineers served as ?interns? under the tutelage of a master builder in order to learn how to design and construct a certain type of structure. This was certainly the case for tunneling projects with various individuals having been identified as tunneling experts as a result of successfully completed projects The master builder approach began to change in the early 1900s to a model that would be referred to today as design-bid-build. A design-bid-build approach to project procurement gives the owner more control over the final product and al-lows the contractor to know exactly what is expected of them before the work is constructed. As a result of this transition in project procurement, civil engineering schools placed a greater emphasis on the training of ?design? professionals. This article will document how the training of tunnel design professionals progressed within the United States. Although it is difficult to generalize about the hundreds of tunnels that were constructed in the first four decades of the 20th century, there is one project that stands out as having resulted in a university program related directly to tunneling and that is the Chicago Subway. During a visit to the United States in 1938, Dr. Karl Terzaghi met a student named Ralph Peck who was then studying at Harvard University in a pro-gram established by Arthur Casagrande. Shortly thereafter, Terzaghi traveled to Chicago for a lecture and was asked to consult on the Chicago subway project that was then under construction. The Chicago subway was being constructed in clay, and the owners were worried about possible settlements to nearby buildings. Terzaghi asked Peck to serve as his field engineer for that project. Thus was established one of the most productive relationships in the history of civil engineering in the United States. Peck, who would become Dr. Peck, moved to Chicago in 1939 to participate in an extensive research project that con-tinued until subway construction was halted in 1941 because of World War II. During that time, the cost of subway construction in Chicago was reduced substantially as a result of Peck?s observations and Terzaghi?s recommendations. In fact, it was reported that subway construction in Chicago cost less than one-half of similar projects in London even though the clay in London is considerably stiffer compared to Chicago. Upon the completion of his work on the Chicago Subway, Peck accepted a professorship with the University of Illinois in Champaign/Urbana.

Jun 1, 2010

To meet the energy requirements, hydroelectric projects are planned and executed in many countries. Though these projects requires a high capital investment, the returns are regular with minimum maintenance after commissioning of the project and are ecofriendly. Bhutan is situated in the eastern Himalayas and covers an area of 38,394km2 (14824.01sq. miles. It is bordered by India in East, South and West and by Tibet in the North. The hydropower potential of the country is estimated at 30,000MW, out of which around 5% has been harnessed.

Jan 1, 2016

By Shawna Munn, Jakub Hudler

This paper outlines the use of tunneling headwall softeyes for transit construction projects in the Greater Toronto Area (GTA) over the past decade. Due to spatial constraints, tunnel boring machines were used to construct the underground tunnels requiring the design of launch and exit shafts with headwall softeyes to facilitate tunneling operations. Variable ground conditions and shaft geometries lead to the development of innovative headwall and tunnel softeye design applications using fiber reinforced polymer (FRP) elements (beams, reinforcing bars, and tiebacks). This paper outlines the challenges and benefits associated with designing and constructing shafts using various systems. Lessons learned throughout design and construction of more than 20 structures over the past 10 years are outlined. The constructability challenges with using FRP and design performance are also discussed. For over a decade, the City of Toronto has been expanding its metropolitan transit network with a variety of new transit construction projects. Two recent projects in the Greater Toronto Area (GTA) for underground infrastructure include the Toronto York Spadina Subway Extension and the Eglinton Crosstown Light Rail Transit project. These add a total of 31 new stations and 18.6 km (11.5 miles) of underground transit (TTC 2017) (EllisDon 2016). Due to ground conditions and spatial constraints of existing surface infrastructure, these projects utilized tunnel boring machines (TBMs) to construct the underground tunnels requiring the design of various types of shafts and headwalls to facilitate underground tunneling operations. To allow for tunneling through the headwalls, these shafts were designed with “softeyes” - a section of the wall without metal reinforcement that allows the TBMs to tunnel through.

Jan 1, 2018

By Camilo Quintero, Frank Cesario, John Kinnear, Brian Boye

In this paper, an innovative approach was adopted to automatically calculate the effects of tunnel induced settlement on buildings and utilities. The approach resulted in increased output quality, consistency, reduced time, cost savings and a greater ability to respond quickly to design changes. The techniques described have been applied to the Fairbank Silverthorn Storm Trunk Sewer System project, located within the City of Toronto. The automation allowed a very large area of topography, tunnels (6 km), buildings (9000) and utilities (over 1000) to be rapidly evaluated. Visualization of the settlements and impacts also allowed the project design team to optimize the system design to mitigate the settlement impacts.

Jun 13, 2021

By Ernest Selig, John Dunnicliff, Delon Hampton

This paper provides a summary of a two-day conference held in New Orleans in March 1980, entitled "Tunnel Instrumentation: Benefits and Implementation." The conference addressed two major questions: First, what are the benefits of using instrumentation during tunnel construction? Second, what contractual relations should be established for conducting instrumentation programs during tunnel construction? Each session consisted of brief formal presentations and extensive panel discussions with participation from attendees. Attendees included owners, designers, contractors, and instrumentation specialists. This paper presents a consensus of views expressed during the conference.

Jan 1, 1981

By John Kinneen, Sunghoon Choi, Arne Fareth, Edward S. Barboe, Kyle R. Ott

A new water treatment plant is to be constructed for a portion of the water supply system of New York City. The project includes construction of new water conveyance tunnels crossing perpendicular and sub-parallel to the existing pressurized water tunnel at two locations. A study was conducted to evaluate the impact of new tunnel construction on stability of the existing tunnel and hydrojacking potential in the surrounding rock mass. This paper introduces a practical approach to evaluate tunnel interaction, expressed in terms of rock-liner interaction, stress-induced stability and hydrojacking failures. A simple method to evaluate hydraulic and mechanical properties of concrete liners and jointed rock mass is also presented.

Jan 1, 2007

By Björn Johansson

"SUMMARY Every tunnel designer has to consider the power of water ingress when designing a new tunnel. Either you choose solutions with simple methods to divert the ingress water or a robust system with the intention that it will give gain on low maintenance costs and a long lifetime. This article describes a new method to divert ingress water in a robust way and more economical than traditional concrete lined tunnels. This system is based on a bolt grid suspending a water tight membrane, which is reinforced and covered with sprayed concrete. The method has been in limited use in Sweden since 2005 and with continuous improvement, still going on, it is now applied for the large project “Stockholm Bypass”, a 21km long highway project. TUNNEL MAINTENANCE RELATED TO WATER INGRESS The Swedish Transport Administration maintain approximately 190 various tunnels that is constructed by a number of different methods, (Swedish Transport Adm 2015). Commonly the ground conditions are good and fairly low ground support is needed. Contrary water and winter conditions can be sever, which gives high impact onto the tunnel design and in particular methods to protect against “frost and water ingress”. During a tunnels lifetime it is common that maintenance related to water ingress occurs several times and sometimes frequent occasions every year. Such maintenance costs and consequences of lost open time for the tunnel can rapidly become higher than the initial cost of the tunnel. Thereby it is obvious that spending time during design to evaluate requirements for a suitable system against water ingress is preferred. Icicles Icicles are formed when water is below freezing degrees and drips or run from an ingress point. At very cold conditions also water flows running at high velocity freeze into ice and a rapid growth can appear. If the integrity of the tunnel traffic area is interfered by icicles they urgently have to be removed before they cause an accident. Typically the tunnel or a part of the tunnel must be closed to do such maintenance. TUNNELS FROST AND WATER INGRESS PROTECTION IN SWEDEN In Sweden methods to perform “frost and water ingress protection” are primary developed for drill and blast tunnels as it is most common tunneling method. The foundation Swedish Rock Engineering Research has done a comprehensive report SveBeFo Rapport 77 that describes water and frost prevention in Swedish tunnels up to year 2005. Below is only slight description of those various methods. Lately some more attention is paid to concrete lined tunnels made by TBM since TBMs successfully built water tight tunnels in City Tunnel (Malmö) and Hallandsås Project. When environmental demands require maintained ground water levels, water tight tunnels made by pressurized concrete lining becomes more economical and on the same time also becomes protected from icicles and water drips."

Jan 1, 2016

By T Isaksson, J Anderson

The procurement process for underground construction contracts, in particular those contacts involving tunnel boring machines (TBMs), is subject to many complex and inter-related variables, including national and local politics, public policy, community involvement and media attention û as well as strict environmental and legal requirements. Other restrictions include the time available to adequately investigate geotechnical conditions and viable technical options to determine the best construction methodologies û including selection of tunnel boring machine characteristics and, those construction means and methods suitable for the specific geotechnical and environmental conditions. The latter are, most often, quite imperfectly understood. æGetting it rightÆ implies that an optimal configuration û of machine type, characteristics and associated methodologies û can be found and successfully implemented for a particular project. æFrom the beginningÆ implies that the lack of time issue can be successfully resolved. Within an international context this paper highlights a number of issues of concern which relate to tunnel procurement systems and the ways in which certain key processes are managed during planning, design and construction. The authors argue that there is considerable room for improvement in the way tunnelling projects are undertaken and an approach is discussed which has the potential for substantial gains in cost and schedule and reduction of risk. Savings, however, may only be fully realised if the new methods can be fully implemented by all parties involved. This, we believe, will require the rejection of ætraditionalÆ forms of management and procurement with associated changes in the roles and responsibilities of owner, engineer and contractor. Additionally, risk identification, assessment and mitigation are essential cost and schedule control process which have, to this point, been underutilised by the underground construction industry.

Jan 1, 1999

By Ronald E. Triplett, George K. Burke, Bernard H. Voor

To accommodate larger double-stack rail cars through a tunnel, the existing active tracks were to be lowered. The tunnel is an elliptical, horseshoe-shape with concrete base support, removal of which would jeopardize the tunnel integrity, particularly since the soils beneath part of the tunnel floor included soft, saturated silt overlying rock. Grouted bar anchors combined with a SuperJet soilcrete strut replaced the existing support in situ prior to floor lowering. Close cooperation and detailed timely engineering support provided a quality project. Project design and construction, ground improvement methods, and the performance of the work are described.

Jan 1, 2001

By Gary English

"Tunnel safety is evolving as science, engineering and technology make advances. Applicable safety codes and standards simply do not cover all the potentials of design, construction and operation. This paper reviews a series of tunnel projects code gaps in Seattle USA that were uncovered during the design and construction of a new highway tunnel, conversion of bus tunnels to combined road and rail tunnels, new rail tunnels using TBM and NATM, conversion of a road tunnel to light rail, and retrofit of an existing road tunnel to add lanes and improve safety systems. The perspectives of the ‘fire code official’ (Authority Having Jurisdiction) on methods to identify and resolve gaps in safety code and standard regulations, while garnering the consensus of the owner, designer, and contractors are presented. Additionally, the emergency responder command perspective on safe tunnel design, tunnel rescue during construction and operational safety is explained TUNNEL SAFETY EVOLUTION The underground has become nearly the only option to provide essential transportation corridors to continue our economic growth in key global areas. Tunnels are not built on a whim. Often significant portion of a regions wealth are invested to meet current, and hopefully future transportation demands. There are more transportation tunnels being built now than at any time in the planets history. The location of these tunnels is often selected for us based upon regional demand. Most commonly under densely populated urban centers and between populations’ centers to bypass geologic conditions like mountains and water bodies. Tunnels are being built in unforgiving soils, between tectonic plates, in extremes environmental conditions and often, under the very heart of the highest density population centers on the planet. All of these locations can bring with it conditions that challenge our common assumptions about safety. These extraordinary locations and soils create risks for both those constructing the tunnel, and in design engineering to meet the ‘minimum’ requirements at the lowest costs. There is lengthy history of above ground safety. Most countries and major local jurisdictions have adopted, or created safety requirements for the construction of above ground buildings. Through decades of use, these safety requirements have evolved, changed and been expanded to cover a wide gamut of actual and potential safety risks. However, the use of the underground for tunnel transportation corridors has grown exponentially with limited attention to safety requirements."

Jan 1, 2016

By Larry F. Drolet

Charleston, SC is anything but boring. The city was founded in 1670 and has played a significant role throughout the history of the United States. Located along the coast of the Atlantic Ocean in the southeastern United States, Charleston was a vital city in America?s early existence. Charleston?s coastal location has helped the city become the fourth largest cargo port in the United States and earn the 2011 designation as the number one travel destination in the United States by the Conde Nast Traveler Magazine. Part of Charleston?s charm and beauty can be attributed to its historic structures and churches that line nearly every sidewalk, roadways that were laid out based on the width of horse carriages, great weather, southern hospitality and coastal living. Now imagine the challenges of installing new, or re-placing aging infrastructure, in this setting. Every shovel full of dirt, every stick of pipe and every roadway sub-surface has its own historic story to tell. For engineering minded individuals, Charleston?s infrastructure has almost as fascinating a history as its more visible surface structures. Charleston was among one of the first American cities to construct separate sanitary and storm water drainage infrastructure. This concept has roots dating back to the city?s founding and is a credit to the foresight of its founding fathers who understood the basic health differences between sanitary and storm water.

Jan 1, 2013

By D. Olsen, S. Cole, J. Strid, G. Colzani

This paper focuses on the underground tunnel work at the Hollywood Water Quality Improvement Project (HWQIP) in Los Angeles, CA. The HWQIP is being constructed to provide a water distribution system to bypass the existing Hollywood Reservoir System, which supplies drinking water for 500,000 people. The major project features include, a 2.9-meter diameter 1,829 meter long bypass tunnel, a 1.8-meterdiameter 366 meter long utility tunnel, 3 jack and bore tunnels, two 136 million liters underground circumferentially wrapped pre-stressed concrete water storage tanks, associated piping, and mechanical facilities. The physical project location coupled with strong community involvement and stringent environmental concerns was a considerable driving force for this project located in the Cahuenga Pass area of the Hollywood Hills north of Los Angeles, CA.

Jan 1, 2001

By John McDonald, Peter C. Raleigh, Christopher Dishlip

This paper will discuss how the construction management team and the contractor working together on the City of Los Angeles, North East Interceptor Sewer project, managed information on a daily basis. Data was synthesized from various sources including: inspection, survey, instrumentation, laboratory and the tunnel boring machine data logger systems to produce state-of-the-art reports and graphics which will become industry standard. Special emphasis is placed on how the data is managed and interpreted in a clear and objective manner, permitting the tunneling processes to be carefully monitored and suggesting appropriate action to be taken by the construction management team and contractor.

Jan 1, 2005

By S. Suwansawat, D. J. Maconochie, C. C. Chang

This paper describes the overall delivery of the tunneling for the Mass Rapid Transit Authority of Thailand’s Chaloem Ratchamongkhon Line in Bangkok and the constraints provided by the alignment. Eight earth pressure balance tunnel boring machines were employed under two major civil works contracts to drive approximately33 kilometers of tunnel in soft saturated ground beneath the crowded streets of Bangkok. Responsibility within the contract for building damage provided an inherent control for ground movement arising form tunneling when the right of way was narrower than the influence zone. These limits affect the earth pressure balance requirements and permissible ground loss. The methods adopted to limit ground movements and deal with the various obstacles to tunneling influenced the design and operation of the machines. The challenges provided by the need to tunnel through numerous lines of piled foundations of canal bridges and overpasses crossing the alignment are described.

Jan 1, 2001

By Robert D. Talvensaari

It is indeed an honor for White Pine, as a member of the copper mining industry, to participate in this Rapid Excavation Conference. Although our presentation, as the title indicates, is not a success story, we foresee, through our experience, future application of boring machines and rapid excavation equipment in the hard rock mining industry. One might ask what a copper mining company would be doing with boring machines and why the gamble on a high-cost, capital investment for a relatively untried application. Perhaps a little background on the White Pine mine and its geology will explain our daring and speculative motives. THE WHITE PINE MINE The White Pine Copper Company, a wholly-owned subsidiary of Copper Range Company, operates a mine, mill and smelter at White Pine, Michigan in the western Upper Peninsula approximately 6 miles due south of Lake Superior. We employ approximately 3,000 people from the surrounding area and mine approximately 25,500 tons of low grade (1%) copper ore per day. The orebody is contained within several distinct sedimentary horizons that comprise the lower 20 feet of a Precambrian formation known as the Nonesuch Shale. Numerous articles and reports have described many aspects of the White Pine operation and the geology. I will brief you only on that criteria which precipitated our interest in rapid excavation equipment and techniques, specifically, boring machines. Mineralogical and optical studies have demonstrated that the siltstones, sandstone and shale beds all contain relatively barren and discrete particles of quartz (25%), feldspar and mica, bonded with

Jan 1, 1974

By Michael J. Robison, Wojciech F. Klecan, Robert L. Horner

Since 1928, nearly 64 km (40 mi) of tunnel have been excavated within the relatively soft Cooper Group, more commonly known as the “Cooper Marl,” for water supply and transporting wastewater in the Charleston area. The majority of these tunnels are unlined and still in operation, while others collapsed shortly after excavating. Tunnel behavior and support requirements vary considerably in this material due to differences in geotechnical properties. The 4.8 km (3 mi) long, 2.4 m (8 ft) diameter Bushy Park Water Tunnel, completed in 1997 for Charleston’s Commissioners of Public Works(CPW), required no ground support. By comparison, the 1.6 km (1 mi) long, 2.4 m (8 ft)diameter Harbor Wastewater Replacement Tunnel now under construction needs continuous support close to the advancing face, despite being located in the same geological formation. Case histories and general guidelines for designing tunnels in the Cooper Marl are presented.

Jan 1, 2001

By Joel Nonnweiler, Rafael Castro, Ross Webb

The three thousand foot long 66-inch diameter Folsom East Interceptor Section2B was completed accident free, on time and under budget with no measurable surface settlement. The tunnel passed through nested cobbles, highly abrasive sands and gravels, and abandoned mine workings with less than five-feet of cover at times. Preventing settlement was critical since the tunnel passed under a heavily traveled state highway. A pilot project to test microtunneling and pipejacking methods in the same ground conditions abandoned both drives before completing the planned drive lengths. This paper discusses performance of the conventional tunneling method selected to excavate the ground and the effectiveness of the ground modification techniques employed.

Jan 1, 2001