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By John Corcoran

INTRODUCTION Content of this Report The 1300m long twin-bore 8.1m diameter Airside Road Tunnels (ART) were excavated beneath the busy taxiways and stands of Heathrow Airport between 2002and 2003. The tunnels were fully completed and handed over to the client for use early in 2005. This paper will describe the purpose of the tunnels, and the measures put in place to minimize the impact of construction on the daily activities involved in running an international airport. Terminal 5 Construction Heathrow Airport is the busiest international airport in the World, with a current capacity of circa 67 million passengers per year, based on existing infrastructure of4 passenger terminals, 1 cargo terminal, 2 runways and 170 aircraft stands. Terminal 5(T5) is being built to increase Heathrow’s passenger capacity by providing the following: 12 additional aircraft stands through redevelopment of the south apron area, in the autumn of 2004 A main terminal building (T5A) and a first satellite (T5B), and 43 additional stands by the spring of 2008, most of which will be able to receive the new generation large aircraft (Airbus A380) A second optional satellite (T5C) by year 2010 A third optional satellite (T5D) by year 2015 The total value of the project is approximately 4.2 billion pounds for the main phase of the works spanning from 2000 to 2007. Purpose of the Airside Road Tunnel The ART has been constructed to support the internal road traffic of the airport between terminals, aircraft stands, runways and taxiways, for passenger buses, service and technical vehicles. The majority of the traffic will be buses transporting passengers between the terminals and their aircraft.

Jan 1, 2005

By Takefumi Takuma, Tsunenobu Nozaki, Masashi Nagano

The city of Naruto in the southwestern part of Japan is situated at the mouth of the mighty Yoshino River. An approximately 1,000m-long levee/bulkhead along one of the river’s tributaries in the city was raised with prefabricated steel panel walls on a concrete base bulkhead. Some sections of the walls’ foundations were combi-walls made of sheet pile cut-off walls and interspaced pipe piles; both of which were installed with press-in piling because the new wall alignment was very close to existing homes and businesses. A Clamp Crane, which clamped onto already installed piles and moved forward and backward on them, was utilized for a segment where the access to its piling location was too tight for a conventional crane or a track-mounted pile driver to maneuver.

Sep 8, 2021

By M. A. Girts

Wetlands can be constructed inexpensively on mined lands to treat small flows of acid mine water. Metals are removed from the water by the wetland vegetation and indigenous bacteria. Full-scale field tests initiated at over 20 mine sites during 1984 and 1985 indicate that water quality can be upgraded to meet discharge standards with relatively minor maintenance requirements. Iron concentrations of 25-85 mg/L in the influent water fall to less than 2 mg/L during flow through a small wetland. Manganese can also be removed, though somewhat less efficiently. At the discharge, pH is easily raised to 6 by flow over limestone.

Jan 1, 1986

By Colin Lindsay

"The Collahuasi copper mine, located at an altitude of 4300 meters above sea level in northern Chile, commenced operations late in 1998. The mine is currently the 4‘h largest copper producer in the world and comprises an open pit, a 60,000 tpd sulphide concentrator, a 15,000 tpd oxide heap leach and SWEW plant and a 200 km concentrate pipeline to a port facility.Constructing, commissioning and operating a mine at high altitude presents unique challenges in terms of the performance of both equipment and people. It is important that these be recognized and carefully considered during the feasibility study and the detailed design stages and the success of the Collahuasi project is largely due to this. The plant design incorporates a number of features aimed at mitigating the problems of altitude and the construction methodology also took into account the particular site conditions.This paper discusses the Collahuasi project team’s approach to planning for the remote location and also some of the problems experienced during construction, commissioning and operation.INTRODUCTIONThe Collahuasi mine is located in northern Chile, some 250 km to the south-east of the port of Iquique and 15 km from the Bolivian border. The mine facilities lie between 3800-4300 m above sea level on the Altiplano, the central plateau of the Andes mountains, and cover a total of approximately 95,000 hectares. Although the area is arid, it experiences an average of 150 mm of precipitation annually and weather conditions can be extreme. Temperatures during the day range between -3 to +11 º C and are generally below 0ºC at night, sometimes as low as -20°C. High energy winds are common and humidity is low. Much of the precipitation occurs during the winter as snow but there also occurs a period during the Chilean summer known as the “Invierno Boliviano’’ (or Bolivian Winter) which is characterized by severe electrical storms and rain."

Jan 1, 2001

By T. A. Rickard

The writing that is effective is woven with a fine texture into an agreeable pattern; it is free from knots, loose threads, and stray fluff. The instrument that weaves this literary fabric, whether it produce a homely sock or a lordly tapestry, a simple story or a learned 'Itreatise, is a disciplined intelligence, as sure as a steel needle, as precise as a swift loom. The simile breaks down at this point, for the product of the pen is instinct with the human spirit and therefore transcends in beauty anything made by a mere machine. If words are to be woven into eloquent meaning, they must be well knit. Upon the relation of words to each other and of groups of words to other groups, known as phrases, clauses, and sentences, depends the success of writing as a means of trans¬mitting thought from man' to man. To be understood beyond question, you should know not only what your words denote but how to build your sentences; you must not only choose your words aright but construct your sentences properly. A sentence is a combination of words that makes complete sense; it says something about something. ' A clause is a subordinate sentence or a sentence within a sentence. A phrase is a group of words without a predicate; it makes sense, but not complete sense. For example: I shall wait for a few minutes before I go home: The whole statement is a sentence; "I shall wait" and "before I go home" are clauses; "for a few minutes" is an adverbial phrase. The orderly arranging of words and of combinations of words is called `syntax'; and from the original Greek form, ouvaeis (suntaxis), is derived the Greek name for an editor,

Jan 1, 1931

By D. P. Bryan

An aggregate resource study was done for southern Washoe County, Nevada, which contains the Reno-Sparks metropolitan area and a population of about 300,000. The study included an inventory of existing operations, projection of future demand, identification of potential aggregate resources based on geology, and determination of economic potential of these resources. Economic potential was determined by the integration of GIS layers that included aggregate potential, distance from market, distance from major and minor transportation arteries, and elevation. The investigation resulted in a determination that resources of high quality aggregate sufficient for future consumption are present in southern Washoe county; the limiting factor for future utilization is accessibility.

Jan 1, 1996

By S. J. Stokowski

Abstract An extensive drilling and laboratory testing program indicates that a construction aggregate resource is present within the Oligocene Sombrerito Formation limestone, southwestern Dominican Republic. The first part of the testing program included the collection, photographing and geologic logging of diamond drill cores to allow lithologic subdivision of the strata into potential quarry layers. The primary lithostratigraphic units are: I- (youngest) approximately 10 m of white, dense marine limestone II-approximately 5 m of white, interbedded dense and chalky marine limestone III-more than 2 m of tan, chalky, calcitic dolomite. Unit I is often altered by lateritic weathering and/or dolomitization. Unit II is often altered by dolomitization. The cores were individually crushed by quarry layer into coarse and fine aggregate sizes for chemical and physical analyses: specific gravity and absorption, MgSO4 soundness, sand equivalent, Atterberg limits of the minus #40 mesh fraction, and LA degradation. The unaltered portion of Unit I is suitable for all construction aggregate uses. Unit II is best suited for crushed stone base. Each of the non-weathered units decreases in coarse-aggregate yield and quality with depth and diagenetic dolomitization. Dolomitization typically causes about 5% lower yield of coarse aggregate, a sand equivalent of about 20 units below the original value an increase in absorption of about 3%, an increase in the LA of up to 13%, and a decrease in the average five-cycle MgSO4 soundness of about 17%.

Jan 1, 1991

By Bruce W. Woolpert

During the SME Board of Directors’ midyear meeting in Monterey, CA Aug. 25, I discussed trends in the construction aggregates industry. Many construction-material suppliers may not have yet fully internalized the changes that are taking place. But the changes are significant. And they have shifted the focus in the aggregates industry from “assets” to “people and innovation.” Construction-material suppliers serve many customers. A typical quarrying operation at Graniterock would have more than 1,000 customers, mostly civil engineering contractors. Along with the push toward people and innovation, there is increased emphasis on vertical integration from aggregates to ready-mix concrete and hot mix asphalt, to final construction. If a company is not vertically integrated, it will at least have strong partnerships with other firms, to deliver a high-quality finished project on time.

Jan 1, 2002

By Dan A. Brown

The following paper was written by Dr. Dan A. Brown, P.E. Brown is an Associate Professor at Auburn University's Department of Civil Engineering. The paper was originally presented at a FHWA's Transportation Research Board meeting and is presented here with the author's consent. Construction and design of drilled shaft foundations in hard pinnacle limestone requires flexibility from all parties involved due to the variability of the subsurface conditions. This article describes some strategies which have been found useful in the Birmingham, Alabama area. The importance of well trained and experienced field personnel in these conditions is noted. It is also vital that engineers understand the construction challenges so as to provide both quality assurance and cost effectiveness in design and in the specifications.

Jan 1, 1991

By Guy Bjorge

IN recent years the Homestake mine has been served by three shafts, the B. &. M., the B. & M. No; 2 and the Ellison, supplemented by an inside shaft, the Milliken, extending from the 2000-ft. level to the 3200-ft. level. In 1932, when a new operating shaft was under consideration, the bottom of the mine was at the 3200-ft. level. The B: & M. and the B. & M. No. 2 shafts were down to the 1550-ft. level and the Ellison was being deepened from the 2600 to the 3200-ft. level. All ore was hoisted at the B. & M. and-Ellison shafts. Levels below the 2600 level, which were under development only, were served by the Milliken shaft. Below the 1550-ft. level, the mine was served only by the Ellison shaft from the surface. Within a few years, when ore reserves above the 1550-ft. level would be depleted, operation would be limited to the Ellison shaft and the auxiliary underground shaft. The Ellison shaft alone was not adequate for hoisting the entire output from the deeper levels and also handling all men and supplies. Further-more, assurance of safety and uninterrupted operation required- two fully equipped shafts to the deeper levels. Therefore a new operating shaft was authorized in November, 1932, and was named for A. J. M. Ross, the mine superintendent.

Jan 1, 1935

By J. F. T. Agapito, G. P. Bratton

A 16 m by 4.7 m by 24.5 m (52 ft by 15.5 ft by 80.5 ft) underground ore bin was constructed at an 810 m (2660 ft) overburden depth in poor quality, faulted and altered intrusive rocks at Molycorp's block caving molybdenum mine. Geological engineering incorporated detailed structural mapping, rock quality classification, in-situ stress field determinations, numerical stress and failure analysis, and convergence monitoring. The ore bin was mined by conventional methods from the top down and utilized a bored raise for mucking. The initial ground support of rock bolts, lightweight steel sets, and reinforced concrete was later supplemented with an array of 6, 12 and 21 m tensioned, grouted rock bolts when wall closure was noted in the upper ore bin area. The supplementary support was optimized by computer analysis and monitoring.

Jan 1, 1985

By Y. K. Wong

This paper describes in detail various problems concerning the construction of a pile-raft foundation supporting a 42-storey tower block. The subsurface generally consists of highly weathered sedimentary rock. A comprehensive instrumentation program is implemented to monitor the behaviour of the foundation system throughout the construction period of the superstructure. Instrumentation observations are highlighted in the second half of the paper.

Jan 1, 2010

By Dirk van Zyl

Natural materials can be used successfully in the construction of heap leach pads. The use of these materials usually result in the least expensive approach for such facilities. Sufficient geotechnical experience has been gained in the design and construction of clay heap leach pads so that they can be used with confidence. A number of operators presently use clay pads in their heap leach facilities; these include Alligator Ridge, Ely, Nevada (gold), and Union Carbide, Gas Hills, Wyoming (uranium). This paper describes the construction and field investigation of a clay pad for the heap leaching of agglomerated precious tailings. The project is located in the Mojave Desert, Southern California. The design had to satisfy operational requirements as well as regulatory requirements. The California Water Quality Control Board (WQCB) was one of the agencies which had to issue a permit for the project. Their biggest concern was the discharge or escape of cyanide into the environment. Rather stringent requirements were therefore placed on the pad design criteria, especially in terms of permeability.

Jan 1, 1983

By Seedsman R. W

Good roads are essential in moving men and materials to and from the underground workplace. Coffey Partners International Pty Ltd (Coffey) has recently completed a underground coal industry funded project on underground mine road construction and maintenance. This paper discusses practical approaches to construction and maintenance of underground mine roads using transferrable civil technologies and innovative techniques. Mine pavements are generally low-cost (relative to civil roads), constructed to varying standards using locally available materials to best meet the mobility needs of the mine. Performance of pavements is thus largely dependent on the environmental conditions, quality of the available road making materials, maintenance policies and available resources. The paper will detail `what causes bad roads?' in various underground environments, available management strategies, construction and water control techniques, road maintenance and vehicle considerations.

Jan 1, 1995

By G. C. Hodgson

Specification and Tests of Rope Wire Chemical Analysis: The range in composition of steel used in the manufacture of wire rope is as follows: Carbon 0 4 to 0.9 per cent Manganese 0 4 to 0.8 Sulphur Not above 0.04 Phosphorus Not above 0.04 The carbon and manganese content are varied according to the gauge of wire to be drawn and the tensile strength required. Generally speaking, best results are obtained from heats where the melt is not of too large a tonnage. The amount of reduction and patenting of the wire is left to the wire maker, who thus has a free hand in meeting the balance of the specification.

Jan 1, 1931

By R Talebi

A research project to better understand the rock mass behaviour and the seismic response has been conducted during the design and construction of the 9215 level at the E-Block sector of the Northern Star Kanowna Belle Mine. The research program was undertaken at a tunnel located 1100 m below the surface with the results applicable to feasibility studies on underground mining projects in highstress conditions, where failure can occur very soon after tunnel construction. Semi-circular excavation shapes coupled with the use of de-stress blasting techniques were designed to monitor the excavation in conditions of very high stress. The ground support was designed considering high energy dissipation ground support schemes (HED) as described by Arcaro et al (2021). The results indicate a decreased rock mass demand due to the change of excavation shape. Also, localised reduction in rock mass stiffness was achieved due to the implementation of de-stress blasting. Finally, increased ground support capacity was gained by the implementation of the high energy dissipation ground support schemes. The Kanowna Belle Mine has significant ore reserves at depths exceeding 1000 m below the surface. The results of this research will be used to optimise the extraction of the remaining E Stoping Block at depths exceeding 1350 m.

Mar 29, 2023

By F. Brost

In 1976, a decision was made to install a conveying system to transport ore 10.3 km (6.4 miles) from the new Eisenhower Partnership Mine to Twin Buttes. The system, supplied and installed by Cable Belt Limited, of England, represents a radical departure from conventional conveyor systems. The driving tension is applied through two endless wire ropes while the belt acts only as the carrying medium. Features of the system are a single 2240 kw (3000 hp) drive and a 60° angle bend. Construction was completed in two years. Full production was attained after several months' operation.

Jan 1, 1979

By William R. Beloff, Franklin M. Grynkewicz, Puza

Construction of the MBTA Red Line Extension through Somerville, MA, called for driving twin tube tunnels through a zone of approximately 83m (273 ft) with mixed face conditions. While the majority of the tunnels were driven through competent hard rock using drill and blast techniques, the mixed face zone was advanced using floating crown bars for primary support. The overburden consisted of medium clay, underlain by water bearing glacial till, over a sloping bedrock surface. Due to the unusual nature of the construction techniques, a program was undertaken by the Contractor to monitor ground movement and stresses in the temporary steel supports. This paper presents a description of the instrumentation employed, as well as the measured ground movements and support stresses. Additionally, the tunneling techniques are briefly presented and commented upon. PROJECT DESCRIPTION The Davis Square to Porter Square Tunnel Contract is part of the Massachusetts Bay Transportation Authorities (MBTA) Red Line Extension from Harvard Square in Cambridge to the Alewife Brook Parkway via Somerville. The 5.1km (17,000 ft) Red Line Extension consists of four major new stations, three of which will be interlinked via tunnel construction, and the remaining station will be the last link of an open cut portion, and a terminal point for this phase of the extension. This 866m (2,790 ft) portion began at Porter Square in Cambridge and rose at a 4% slope through Somerville, terminating at the new Davis Square Station. Twin tube tunnels were constructed through 763m (2,517 ft) of rock and 83m (273 ft) of mixed face conditions at the Davis Square end. Figure 1 presents a plan view of the entire contract.

Jan 1, 1981

By Robert W. Freedman

In the Bureau of Mines study, a filter with a 20-by 20-inch-square cross section was inserted into the exhaust ducting of a 4-stroke-cycle, 90-hp diesel engine, and the efficiency of removal of total particulate was measured gravimetrically as a function of time. Removal efficiencies were close to 90 pct during the main portion of several extended runs employing several combinations of filter beds. Variations in engine load had little effect on collection efficiency. Particle size as measured by a Bureau-developed online instrument centered on 0.07 m based on number count. Removal efficiency increased rather sharply for both larger and smaller particles.

Jan 1, 1979

By Martin D. Larisch

The construction of diaphragm walls and most large-diameter bored piles (piers) is often carried out under drilling support fluids to temporarily stabilise the excavation prior to concrete placement. In most cases such fluids are either mineral-based slurries (bentonite) or polymer support fluids. The working mechanisms of these two fluid types are fundamentally different. Designers need to consider possible fluid-related impacts on the permanent design performance of the project-specific deep foundations as well as for the temporary excavation stage during construction. Robust design methods for bentonite slurry-supported excavations have been developed in the last few decades and the working principles and associated risks of such mineral-based slurries are understood reasonably well. However, such meth-ods have not been developed in detail for polymer-based drilling fluids. This document provides a brief overview of the main characteristics of bentonite- and polymer-based drilling fluids as a guide for construction practitioners and design engineers alike. The paper also high-lights some common construction risks related to casing installation and the selection of suitable fluid systems for different ground conditions. Typical defects caused by the incorrect application of drilling support fluids, and their pro-active mitigation, are discussed, too. In addition, the basic concepts of sta-bility calculations for bentonite fluid-supported deep excavations are briefly introduced and their ap-plicability for other fluid types such as polymer-based support fluids or water are reviewed.

Nov 1, 2022