News from around the world

  • Published on
    26-Jun-2016

  • View
    213

  • Download
    1

Embed Size (px)

Transcript

  • Meeting Stresses Cooperation Between Miners, Tunnelers At the annual meeting of the

    American Society of Civil Engineers' Underground Technology Research Council (UTRC), miners and tunnelers alike urged cooperation between the two industries to further technological research and development.

    The meeting, held Oct. 24 in Denver, Colorado, was supple- mcnted with site visits to several nearby mines and tunnels. Progress reports on ongoing work by several UTRC committees accounted for most of the meeting.

    Andrew McKown, chairman of the UTRC's committee on perimeter control blasting, presented his committee's report, which is nearly complete after five years of study.

    Perimeter control blasting is an important method of reducing overbreak, reducing water inflow, reducing concrete/shotcrcte backfill, reducing rock reinforce- ment requirements, increasing worker safety, and reducing slope maintenance.

    McKown described three different perimeter control blasting methods for (1) open-cut excava- tions (line drilling, cushion blasting, pre-splitting); (2) tunnels (smooth blasting); and (3) special cascs (fracture control blasting).

    Because geologic aspects arc extremely important in perimeter control, the UTRC committee has developed a rock classification system to help in assessing the most suitable perimeter measures that should bc used in a particular case. Parameters of the classification system are the strength and soundness of the intact rock; the degree of fracturing and spacing of discontinuities; joint orientation; and the condition of joints.

    McKown discussed several conclusions drawn from the two case histories presented in the report. These include:

    I. The need for adequate information regarding geologic conditions expected to be encountered at the site;

    2. The need for smaller spacing and loading than is conventionally used, where fractured and/or weathered rock is encountered and perimeter control is important.

    3. The need for the U.S. to develop a small-diameter, low-

    density cartridge explosive, with a charge weight in the range of 0.06 to 0.15 lbs/ft. (similar to the Gurit explosive manufactured in Sweden).

    4. The use of the Half Cast Factor (HCF) in evaluating perimeter control results. The HCF is an easy and convenient measure of the degree of perimeter control achieved, and can also be used in specifications to state the degree of perimeter control that a designer wishes to have achieved.

    McKown concluded that the case histories had shown that "substantial savings can be achieved through perimeter control loading," provided that an appropriate p.c. method is chosen and that technical factors such as drilling accuracy and first-row-in-hole placement arc accounted for.

    The UTRC hopes to publish the committee's final report by the cnd of 1988.

    A UTRC committee on tunnel lining methods, is developing a book on selecting and dimensioning tunnel linings. The philosophy of design and the philosophy of analysis for tunnel linings will be covered in the book. Background information on the various lining methods will bc provided to help understand their advantages and disadvantages. The book will show how to use analysis for various support types, and will provide examples of methods of analysis.

    Committee chairman Dr. Stanley Paul of the University of Illinois briefly described the lining methods that will be covered in the book: empirical methods, closed form methods, beam-spring method, and finite element methods.

    Paul's presentation focused on the advantages of the beam-spring method, and how to overcome its potential disadvantages (e.g., difficulty in selecting spring parameters and loading to be applied; difficulty in modeling joints and cracks; difficulty in modeling construction sequences).

    Oil mining consultant Robert Miller presented a report on oil recovery from an underground platform. According to Miller, the U.S. is facing an oil crisis, which oil mining can help alleviate. Based on figures from the U.S. Department of Energy, the U.S. could recover 300 billion barrels of

    oil. However, Miller said, existing conventional technology is inadequate for this recovery task.

    An underground platform provides a drilling base close to the oil, and can permit oil recovery in areas where conventional oil recovery methods cannot be used.

    The targets for oil recovery by underground platforms are aban- doned oil fields (often character- ized by low surface flow rates and uncontrollable reservoirs); oil fields that are inaccessible by conven- tional recovery techniques because of high-density urban development (as in the Los Angeles area) or environmental restrictions (as on the California coastline); and "problem" oil fields, where heavy oil, tight reservoirs or structural complexities prohibit the use of conventional technology.

    Miller noted that to improve oil recovery technology, the oil industry must cooperate with civil engineers.

    Miller's message was echoed in a lunchcon address by Norman Anderson, former chairman and CEO of Cominco Ltd., who dis- cussed tunneling and underground construction from a miner's perspective.

    Anderson stressed the need for miners and civil engineers to share ideas and technology. Increased international competition and dcveloping technology mean that "we have to work harder and smarter to compete with other countries," Anderson said. "And research has to bca major component in 'working smarter.'"

    Comparing tunnel boring machines with drill-and-blast technology, Anderson said that his impression was that "hard-rock mined tunnels will continue to be driven convcntionally for awhile, partially because of the versatility of drill and blast." However, he noted, given a good mucking system and good rock, "a TBM would have the advantage."

    Other progress reports dealt with the activities of UTRC committees on the history of tunneling, tunnel rehabilitation, and expert systems.

    A final report on contracting practices, the draft of which was discussed at length at last year's UTRC meeting, is nearly complete and should bc available early in 1989.

    News from around the World Austral ia

    Australia's largest underground bus terminal went Into operation earl ier this year, providing some 30,000 shoppers daily access to Brisbane's Myer Centre. The aboveground Victorian-style shopping complex encompasses a large department store, more than 250 specialty shops, eight movies, two taverns, a food and leisure village, and a carpark for 1450 vehicles. Escalators, elevators and stairs convey passengers to the

    shopping level from and to the new underground terminal, which cost A$25 million. All of Brisbane's southern and western bus routes now pass through the tunnel to pick up and discharge passengers. The development has boosted inner city public transport and about half the people visiting the shopping complex from now on are expected to come by public buses. The tunnel and station have been soundproofed and a ventilation system has been installed that changes the air in the tunnel every

    I I0 seconds. The road surface inside the terminal is painted a bright yellow to brighten the appearance of the underground environment.

    India .

    India's Andhra Pradesh State Electricity Board in Hyderabad is planning a 420-Mw, coal-fired powerplant at Muddanur in southern India. The national government's planning commission

    Vo lume 4, Number 1, 1989 TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY l l 1

  • has approved the first stage of the project, expected to cost $390 mill ion and be completed by 1991. The state agency, which plans to build two more units of 420 Mw each during the next decade, is seeking foreign f inancial assistance.

    from smoking in stations can enjoy guilt-free smoking," said a rai lway spokesman. A recent rai lway station survey found that more than half of the passengers interviewed wanted to see a total ban on smoking in stations.

    option is a l ink between the Norwegian and Danish gas transportation systems in the North Sea and del ivering gas to Sweden through Denmark. However, this is the least attract ive option for Norway.

    India's National Thermal Power Corp. Ltd. will rebid a turnkey contract for a 600-Mw combined-cycle powerplant at Kawns in the western part of the country. NTPC, based in New Delhi, has not set a new bid date. France's Alsthom Atlantiquc submitted the lowest proposal, US$253 mill ion, in May 1986. Although the award was announced last November after protracted discussions, the contractor and NTPC could not reach a formal agreement to proceed. The plant will have gas turbines with a total capacity of 400 Mw and steam turbines generating 200 Mw. The Kawas plant is one of three combined-cycle stations slated for northern and western India.

    Japan

    A study on the creation of a huge dome-shaped space 50 m below ground was launched in September by an advisory panel to Japan's Ministry of International Trade and Industry (MITI). The panel will consider both legal and technical aspects of creating and using an underground space with a diameter of 50 m and a height of 30 m, M1TI off ic ials said. No site for such a project has been chosen, but it would be in the Tokyo metropolitan area or in another major city. The technologies to be studied include a method of analyzing and assessing deep underground structures, development of an excavator that can make a sharp turn below the ground, and control l ing the environment of dccp underground space. The panel will consider legislation call ing for land owners to give up their ownership rights to space more than 50 m or 100 m below the ground. As envisioned, the underground space would have complex energy supply facil it ies, information-processing centers, distr ibution centers and waste water recycling facil it ies. MITI plans to allocate 20 bill ion yen for the project in the next seven years.

    A smoking ban has gone into effect at most stations of the 10- line subway system In Tokyo in response to the disastrous London Underground fire in November 1987. A total of 191 Tokyo subway stations arc affected; the only exceptions arc six transfer stations under the control of the rai lway lines. Large bi l ingual poster with the "no smoking" message in Japanese and English arc posted throughout the system. The private successor railways also have begun to crack down on smokers. The East Japan Railway Company has opened a special smoking area in Tokyo Station. "This way,'smokcrs who have been pressured to refrain

    The capital city of Japan's northernmost island has developed a unique system for heating and cooling downtown buildings, employing waste heat from the municipal subway system that is used by more than half a mill ion passengers daily. Sapporo (pop. 1.6 mill ion) is now building an energy- eff ic ient district heating plant that will recycle heat generated by passengers, lights, elevators, other machinery and trains. The system, the first of its kind in the world, is expected to be operational by April 1989. The plant is expected to reduce heating costs for the buildings it serves by about 40%, while providing heat for an indoor swimming pool, greenhouses and a road de-icing system. The project is expected to recover its capital costs in seven years and begin making profits in 14 years. Made possible by publ ic/pr ivate cooperation, the plant will be run by a company funded by public (55%) and private sector (45%) contributions.

    The introduction of a "fuzzy control" in the automatic train operation (ATO) system that guides Japan's newest subway in Sendal (pop. 710,000) has made it what may be the world's most technologically advanced metrorail system. Developed by Hitachi on the theoretical basis of the fuzzy set theory formulated in the U.S. during the 1960s, Sendai's computerized fuzzy control system allow the complex thought processes of an experienced motorman at the control to be incorporated into the subway's control programs, making for smoother acceleration, deceleration and braking. The fuzzy control system used for the 13.6-kin, 16- station Scndai system is considered a vast improvement over the standard ATO, which requires constant adjustment of quantitative digital data, resulting in a jerky, uncomfortable ride. Scndai is said to be the first heavy rail metro system that has successfully incorporated fuzzy control into its ATO system.

    Norway

    A Norwegian industry group has concluded that it is technically and economically feasible to build a natural gas pipeline from the offshore Haltenbanken fields or from western Norway to markets in eastern Norway. Among the possibil it ies are a line to shore west of Mole or Trondheim, and a 250- mi. l ink between Hantenbanken and the North Sea gas grid. Two options for shipping gas to eastern Norway are being considered, both of which could be modif ied to export gas to Sweden. Another

    Pakistan

    The Development Authority of Karachi, Pakistan, and the city's Water and Sewerage Board are planning a US$375-mill ion, second- phase program to increase water supply by 100 mgd and boost the collection and disposal of wastewater by 94 mgd. Inter- national institutions have already pledged assistance amounting to 78% of the cost. The improvements are to be completed by 1993. Meanwhile, the Capital Develop- ment Authority in Islamabad has again invited f irms to prequality to design and prepare bid documents for a $163-million project to supply 102 mgd of water to the Islamabad- Rawalpindi metropolitan area. An earl ier prequal i f icat ion was cancelled because too few applications came from Japan, which is providing the funding. Firms from other countries will be considered as well, however.

    People's Republic of China

    The Asian Development Bank will recruit consultants to study the planned Guangzhou pumped storage power station in China's Guangdong Province. The Guangzhou project would include two dams and a four-unit powerhouse producing a total of 1200 Mw at Lu Tian, about 55 mi. northeast of Guangzhou. It would cost more than US$300 million. The hydroelectric station would be teamed with the Daya Bay nuclear plant, which would supply power to pump water to the upper reservoir during off-peak hours. The twin 985-Mw nuclear units are under construction nearby at a cost of $4 bil l ion by French and British groups. The Asian Development Bank proposes to provide technical assistance for the project. Init ial engineering services to be sought by the bank will cover an evaluation of alternative designs of power tunnels and manifolds, and supervision of the construction of those structures. The project will operate under an extremely high head--about 1760 ft. It is due for completion by 1992.

    China's Ministry of Water Resources and Electric Power, its Ministry of Railways and the Shanxi provincial government plan to hire consultants to conduct a feasibility study of a coal-fired powerplant in Shanxi Province. The Liu Lin generating station invol...

Recommended

View more >