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Reclamation of surface mines is a crucial environmental issue and a key challenge to the worldwide mining industry. One of the goals of reclamation is to ensure that the area is left in a condition permitting safe future use. Hence, the reconstruction of open pits, waste piles and tailings dams must satisfy appropriate geotechnical stability and safety conditions for the planned use. Landscaping in the final stages is highly relevant as the topography around the mining areas is sometimes dramatically modified by ore extraction. The reclamation strategies must be applied not only after ore exhaustion, but also during its extraction. This is a sound business strategy that leads to considerable environmental benefits and increased security of the mining operations.

Jan 1, 2003

By Mark R. Rybak, James Delmonte, Travis Hartman

The City of Phoenix, Arizona designed a 7.2 km (4.5 mi) long water transmission main from the South Mountain Reservoir to the Ahwatukee Foothills Reservoir to address the growing demand for drinking water in the southeast valley. The pipeline design called for a bored tunnel in a very environmentally sensitive area. The Reach3B contract included an 2.44 m (8 ft) diameter TBM excavated tunnel, 1,847 m(6,060 ft) in length. The geotechnical investigation revealed that the tunnel would likely pass through zones of loose to moderately cemented soils (caliche). The primary tunnel support would consist of rock bolts, circular steel ribs, hard wood lagging, and mine straps. A TBM that could handle the ground conditions and allow for efficient ground support installation was required. This paper describes the construction of a small diameter rock tunnel in challenging ground conditions.

Jan 1, 2003

By Josef Arnold, Norbert Fuegenschuh

The “Eggequerung” is an important part of the German Railway’s (Deutsche BahnAG) modernized Dortmund—Kassel line. The heart of this 13-km-long (8 miles)construction lot is the double-track Egge Tunnel with a total length of 2,880 m(9,450 ft.). The tunnel was driven using the New Austrian Tunnelling Method (NATM).The construction contract also called for a reinforced concrete secondary lining, guaranteed for a full water pressure of 30 m (100 ft.) water column. Preliminary geological study already showed that very problematic geological-hydrological conditions would have to be expected. This talk describes the chosen NATM driving concept that was adapted to the prevailing geological and hydrological conditions, the special driving method applied in geologically difficult zones as well as the water control concept used during driving. The flexibility and the limits of the NATM under exceptional hydrological conditions are illustrated. Also described are reinforced concrete lining works for the watertight secondary vault (reinforced concrete secondary lining without water-proofing membrane).

Jan 1, 2003

By Bruno Mattle, Max John

For tunnels with low overburden, the shotcrete lining is the main element of ground support, which is why shotcrete behavior is of prime importance. Following its application, shotcrete not only gains strength and stiffness with time but—if loaded at an early stage—it is also subject to creep which in turn leads to stress relaxation. For two-dimensional FE calculations, a computational modulus of elasticity of shotcrete is to be used. Based on parameter studies it was found that the modulus of elasticity of shotcrete depends on both shotcrete mix and ground behavior. While the Young’s Modulus used for young shotcrete may range from 1,000 to 7,000 MPa, the Young’s Modulus used for hardened shotcrete is best represented by a value of 15,000 MPa.

Jan 1, 2003

By T. R. Ellis

Considerable movement is afoot internationally to rationalize standards and regulations relating to valuations and the qualifications for valuation professionals. In July 2000 the International Valuation Standards Committee released expanded standards, and additional important improvements are planned by 2003. Possible updates to the International Accounting Standards (IAS) and potential adoption of IAS by the United States could significantly impact minerals appraisers. Standards designed specifically for mineral asset valuation are under development in Canada and the United States, with Australia's internationally respected VALMIN Code providing the benchmark. In the United States, the all-encompassing Uniform Standards of Professional Appraisal Practice (USPAP) is annually modified and continues to gain deeper acceptance, while the SEC holds fast to its 1981 rule prohibiting reporting of a quantitative estimate and value for non-reserve mineralization. Some important international trade agreements are driving actions to free the trade in professional services. In July 2000, an international workshop was held to initiate discussion on minimum qualifications for appraisers to work internationally. Pressure for uniform minimum qualifications and rules for professionals internationally will continue to build. The United States is historically among the slowest countries to implement such initiatives, with its state level licensure barriers having the potential to cause some of its professionals to be stranded in an international backwater. Structural change is needed in Australia's VALMIN Code to remove conflict with the latest International Valuation Standards. The mineral valuation standards developers of Australia, Canada and the United States should work jointly on updating VALMIN for global use.

Jan 1, 2003

By Faruk Oksuz, Clay Haynes, David Egger

The United States Army Corps of Engineers (USACE) has committed to solve a major drainage problem in the suburban Chicago community of Griffith, Indiana. The Cady Marsh Ditch is currently undersized and on occasion spills its banks causing flooding and economic setbacks to the community. Preliminary studies have identified both tunnel and surface solutions as being attractive and viable. The USACE has decided that this project is an opportunity to use the design-build contracting approach to maximize ingenuity in project approach and to allow the market to dictate whether a surface or subsurface solution is most attractive. The tunnel would be over one-mile in length through sands, gravels and clay. Water control will be an issue during tunneling. The paper will explore the contracting approach to the project and the adaptation of Underground Technology Research Council (UTRC) guidelines for underground contracting to a design build project. The roles of Owner, Owner’s consultant, and design-build contractor will be defined as interpreted by the USACE and key contract provisions will be described and contrasted with a traditional design-bid-build approach to tunnel construction.

Jan 1, 2003

By Martin Knights, Geoff Featherstone, John Flanagan, David Lawrence

The proposed paper will address specific transport, engineering, environmental and community related issues concerning the current construction and future operation of Europe’s biggest urban road tunnel project—the US$500m Dublin Port Tunnel. Situated in Ireland’s capital, the three mile long, 40 ft diameter twin tunnel project encounters a range of ground conditions using TBM, Shield, Cut & Cover with diaphragm walling and major slope stabilisation and Multi-jacked pipe techniques. Where possible units of measurement are given in feet and inches.

Jan 1, 2003

By Moussa Wone, V. Nasri, F. Guimbal, D. Andre

The Magenta underground station was constructed in the heart of Paris in saturated soft soil and at shallow depth. To investigate the surface settlement and the deformation of the concrete liner, innovative techniques combined with a vast campaign of monitoring were applied. The monitoring data and a simple three-dimensional ?nite element analysis were used to assess the accuracy of the two-dimensional ?nite element model originally utilized in the design of the station. The deformation of the concrete liner was monitored using vibrating wire extensometers. Their performance was validated by the data obtained from monitoring and also by a simpli?ed ?nite element analysis.

Jan 1, 2003

P&H MinePro Services Canada is supplying Syncrude Canada three more of its model4100BOSS electric mining shovels. The shovels will be delivered during 2003. Syncrude’s oil sands operations already use five P&H shovels. The first 4100BOSS shovel was commissioned at Syncrude’s operation in northern Alberta, Canada in October 2001. The unit loads more than 9 kt/hr (10,000 stph) of unblasted oil sands. Since it began operation, the 4100BOSS has shown a 28% production increase over the four P&H 4100TS shovels also on site.

Jan 1, 2003

By David Court, Rab Brown

The paper discusses the work in progress on the construction of the extension of the High Speed Rail line from the Channel Tunnel into the centre of London UK known as the “Channel Tunnel Rail Link” (CTRL), and particularly on contract 250 which involves the construction of two 5.3Km tunnels 7.15m diameter constructed with two EPB convertible tunnelling machines underneath the densely populated area of East London. In addition the paper will look at an innovative Alliance that has been formed between the Contractors and the Client’s Engineer involved in the construction of the London Tunnel Contracts

Jan 1, 2003

By S. Nickson, M. Grenon

Oriented borehole data provide the means to characterize a rock mass. In this paper, the geomechanical caving potential of a hard rock mine project is investigated. In particular, the influence of random joints to the resulting block size distributions is addressed. The implications of this approach in preliminary investigations on the choice of mining methods are discussed with reference to one site.

Jan 1, 2003

By Wolfgang Güter, Paolo Romualdi

Current extensions of the European railway network require long TBM drives in the diameter range of 10 m under critical and varying rock conditions. In view of that and in particular for a 7 km long high-speed railway tunnel in Spain to be started in mid-2003 a new design for a hard rock Double Shield TBM has been developed by SELI (Italy) and Jäger (Austria) in collaboration with Mitsubishi (Japan)and Robbins (USA). Due to the new design and operational features that new type of TBM has been named Universal Double Shield TBM with a further extended area of application. Special attention has been given to outstanding torque and thrust capacities combined with the shortest possible length of an innovative shield arrangement, different advance modes in various ground conditions and further developed exploration and treatment facilities.

Jan 1, 2003

By Bernie W. Martin

The East Side Access (ESA) project is the largest commuter railroad project ever undertaken in the United States. The purpose of the ESA project is to bring commuters from Long Island into Grand Central Terminal. The program is estimated to cost $4.3billion. The purpose of this paper is to describe the key design elements for the Queens segment, ?re life safety, ventilation and changes to the proposed contract delivery method.

Jan 1, 2003

By Hugh E. Cronin, John Ramage

The recommendations resulting from a Dispute Review Board (DRB) hearing of a contract dispute are being challenged more and more frequently. This paper explores possible causes based on the authors’ experiences. Challenges facing the DRB process include: The DRB process is starting to lose some of the informality and flexibility. Both owners and contractors appear to be putting too much weight on a board recommendation on a dispute. DRB’s do not make “decisions,” they provide recommendations for dispute resolution to both parties. The DRB process is not just for contractors to present an unresolved issue to a board hearing. Owners can also initiate a request for a hearing on a disputed issue. For the DRB process to remain a viable element of the successful construction project, confidence must continue to be maintained in a process that is intended to work on behalf of both parties to the construction contract.

Jan 1, 2003

By Ulrich Maidl

The use of EPB shields in the so-called mixed face conditions has set new demands to man and machine in EPB shield tunneling. EPB shields were initially conceived to drive in the pressurized closed mode in soft ground, whereas hard rock TBMs were designed to work in the unpressurized open mode. The present use of EPB shields in hard rock and mixed face conditions requires the combination of both technologies by finding best compromise solutions. This paper deals firstly with the geotechnical and mechanical interactions between machine and ground. Further on the critical points such as tool wear and tool replacement are exposed, together with a proposal of best solutions.

Jan 1, 2003

By Reginald Dias

Mining operations take a tremendous toll on equipment, operating in difficult conditions day after day. Owners and operators cannot make the job any easier, but they can give their equipment an advantage. Equipment life may be extended through preventive maintenance and the proper application of quality lubricants. This means lubricants that are made to last longer and stand up better to the punishment mining equipment must endure. There are several practices to consider as part of a successful preventive maintenance program. A good place to start is to review original equipment manufacturer recommendations about servicing and maintenance intervals for each part of the equipment, especially the engine. If these recommendations have not been followed, owners and operators must begin periodic service work on equipment to help minimize equipment down-time and extend engine life.

Jan 1, 2003

The Awareness and Preparedness for Emergencies at the Local Level (APELL) program is a process that helps people prevent, prepare for and respond appropriately to accidents and emergencies. APELL was developed by the United Nations Environment Program, in cooperation with industry groups, governments and local communities. Since its beginnings in1988, the program has been implemented in more than30 countries. APELL is a tool for bringing people together to allow effective communication about risks and emergency response. The program provides a common-sense approach to accident prevention and response.

Jan 1, 2003

By Victor M. Mercado, Jay B. Shah

Spalding DeDecker Associates, Inc. (SDA) designed a tunnel project that fulfilled the Sustainability Objectives of Social Equity, Environment, and Economics. The project translated the principles of Sustainable Development into actions that lessened the impacts of construction on environment, lives of residents, businesses, traffic, and other social systems (i.e., shopping, recreational, and educational). The project involved the construction of a 16,108 feet of 84 inch diameter sanitary sewer interceptor by tunneling 40 feet beneath the ground surface through difficult geological and hydrogeological settings. An effective public information and stakeholders relationship program was developed to achieve the stated objectives of sustainability.

Jan 1, 2003

By Del Brock, Dan Wooton

The design/build of two adjacent vertical mine shafts in difficult ground conditions at a mining complex in the midwestern United States required innovative construction techniques. Construction of the 267-m-deep Service Shaft required full depth dewatering wells and ground freezing. Blind drilling was utilized to excavate the 257-m-deep Production Shaft and it was finished with a steel/concrete composite liner that was floated into place. An equally unique component of the installation included supplying a high capacity vertical conveyor system, featuring a 273-m-lift. Other components of the project include the mine level development, as well as the design and installation of three hoisting systems, including a 45-ton capacity men/materials hoisting system.

Jan 1, 2003

By William F. Ryan, Paul T. Gribbon

With the rise in construction claims in public works contracting over the years, the use of Dispute Review Boards (DRB’s) in underground construction contracts has become quite common. However, in order for the DRB process to be an effective tool, there must be complete trust and confidence in the Board members and their adopted procedures by both the owner and contractor. This can be difficult in an industry where Board members and contractors may be well known to each other, while an owner maybe involved in a large complex underground project only occasionally. Using case histories, this paper will discuss some recent experiences with the DRB process from an owner’s perspective.

Jan 1, 2003