Geotechnically Speaking.issue 5

8/16/2019 Geotechnically Speaking.issue 5

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02 Threading a needle through Olympic

venue with B.C. hydropower project

03 Out of the ashes: expertise in dams,

soil mechanics aids U.S. coal plants

04 Soil covers in northern climates:

seeking better solutions to burying

problem wastes

05 News from Golder’s

Ground Engineering Group

06 2009 and 2010 Milligan Awards

07 Going where the wind blows:

grounding turbines in varied terrains

07 CO2 sink or swim: testing carbon

capture in Ketzin’s saline aquifer

Issue 4 • 1st Quarter 2009

Golder marked 50 years in 2010. The company has grown into a global operation over this time. Through

the vision of our founding fathers and our collective will to maintain technical excellence and innovation into

existing and new market sectors, we are a sustainable entity of which we can be proud.

It is fitting therefore that this 50th anniversary edition of Geotechnically Speaking (GtS) highlights some

of the diverse and innovative ways that Golder is providing ground engineering services in efficient and

sustainable energy development and allied fields. The demand for energy (nuclear, hydro, oil and gas) and

for efficient methods for dealing with the waste from these activities keeps growing, and we are also active

in these new markets.

Areas where we are providing geotechnical expertise include the development of run-of-the-river

hydroelectric power schemes, developing and applying advances in critical state liquefaction research to coal

ash impoundments for the coal-fired power industry, wind farm power generation, and soil cover design in

cold regions to mitigate the negative environmental impacts of waste rock and tailings from uranium mining

operations.

This issue also highlights Golder’s recognition of our contributions to excellence by announcing the winners

of the 2009 and 2010 Milligan Award for technical papers published by Golder staff in the field of ground

engineering.

Paul Schlotfeldt Senior Rock Mechanics Engineer, Squamish, BC, Canada

From Earth to Energy

CRAZY HORSE FIELDPROGRAM CAPTIONGOES HERE

TAKING ROOT IN THIS RUGGED TERRAIN IS A NETWORK OF

48 VESTAS V90 WIND TURBINES. BEGUN BY EARTHFIRST

CANADA AND CARRIED FORWARD BY PLUTONIC POWER AND

GE ENERGY FINANCIAL SERVICES, THE COMPLETED WIND

FARM WILL DELIVER 333,000 MEGAWATT-HOURS PER YEAR,

THE LARGEST OPERATING WIND FARM IN BRITISH COLUMBIA

(SEE PAGE 7).


2/7

CHARLIE HARRISON AND RICH HUMPHRIES

SQUAMISH, CANADA

Nestled in British Columbia’s rugged Coastal

Mountains, the bobsleigh track built for the 2010

Winter Olympics is one of the fastest and most

scenic in the world. Running beside that track is

another, less visible but equally ambitious con-

struction project—the Fitzsimmons Creek Hydro

Project. This run-of-river hydroelectric plant will

harness the energy of the water flow to generate

7.5 MW of electricity—enough to power the sum-mer and winter operations of the nearby Whistler

Blackcomb resort.

The small footprint of a run-of-river project makes

it an environmentally attractive option for renew-

able energy. But the limited space in the valley of

Fitzsimmons Creek presented the team with an

array of geotechnical, hydraulic, and construction

challenges. Surmounting them in time for com-

mercial operations to begin in 2010 has required

close cooperation and coordination between the

design team (RSW/Golder), the contractor (Ledcor

CMI), the developer (Innergex/Ledcor Power), and

the Vancouver Olympic Committee.

Placing the penstock

Chief among the challenges was the placement of

the penstock, the pipeline used to channel water

from the intake point on the creek to the power-

house 4.5 km downstream--an elevation drop of

nearly 250 m. Initially, the developers had planned

to install the penstock prior to, or in conjunction

with, the bobsleigh track, which began construc-

tion in 2005. However, permitting and regulatory

issues delayed the installation of the penstock un-

til after the bobsleigh track was completed. That

meant the penstock had to be “shoehorned” into

the snow cat road, between the utilities for thebobsleigh track and the edge of a steep natural

slope that drops down to Fitzsimmons Creek.

The proximity of the nearly completed Olympic ven-

ue posed several potential concerns, including the

risk of undermining the newly constructed retain-

ing walls and possible mobilization of deep-seated

slope instability. Through the area adjacent to the

bobsleigh track, the team had to thread the pipe

alignment between potentially unstable slopes,

the bobsleigh track, and the utilities for the track.

This necessitated a number of sharp bends where

concrete anchor blocks, typically 2.2 m wide by 2.2

m high were placed. In three locations where theblocks are on slopes greater than 20°, additional

anchors were incorporated.

Where the penstock had to be constructed near or

at the crest of some very steep slopes (35° to 44°)

of marginal stability—particularly at the Men’s

Start area, and at curves 4 and 7 of the track—

the slopes were further stabilized. Micro piles,

containing 32 mm to 42 mm diameter reinforcing

steel bars, were installed vertically into the slope

to increase the sliding resistance.

To further lessen the potential for a slide, light-

weight cellular concrete fill was used in some

areas around the penstock. This consists of a ce-

ment slurry infused with a foaming agent to pro-

duce a hardened concrete product that weighs less

than water, with a strength that can reach upwards

of 1 megapascal (145 psi).

Another concern was the secure placement of

the powerhouse. In the downstream sections ofthe project, the slopes are particularly steep; at

the powerhouse site, the incised valley is roughly

60 m deep. Hazard assessments identified sev-

eral ancient and recent slope failures in the area,

the most notable being the feature known as the

Fitzsimmons Slump, on the opposite side of the val-

ley from the new penstock and powerhouse.

Protecting the powerhouse

To keep it out of the line of debris flows and out-

wash flooding from the creek, the

powerhouse was tucked in at the

toe of a steep natural slope. The

area available for the powerhouse

and supporting infrastructure

was relatively small and uneven,

necessitating a steep rock cut in

weathered and sheared bedrock

at the base of the natural slope.

The resulting cut slope is about

20 m in height and has shallow

overburden at the crest of the cut

face. A slope angle of 56 degrees was selected to

minimize the rock support needed, so only draped

mesh is required to contain surface ravelling.

The narrow confines of the creek also governed the

design of the intake and spillway structures. To ac-commodate the high sediment load during flood

conditions, a Coanda-type intake was installed. The

Coanda is designed to be self-cleaning: an accelera-

tion plate at the head of the Coanda’s 1 mm screen

increases the velocity of the water to the point

where all debris passes over the weir, preventing de-

bris and large sediment from entering the penstock.

A significant concern were the soft sediments on

which the intake and spillway had to be constructed.

Detailed seepage analyses were carried out to deter-

mine whether a cut-off wall, an upstream impervi-

ous blanket, or other measures would be required

to limit under-seepage and control uplift pressures.These analyses indicated that no special measures

were necessary, resulting in significant savings for

the project. Lock blocks covered by concrete slab

were installed downstream of the intake and spill-

way to direct the water jet further downstream, min-

imizing the potential for undermining the structures.

Although space constraints and complex geology of

the site added greatly to the challenges of design

and construction, the Fitzsimmons Creek project

has thrived. There was no interference with the op-

eration or infrastructure of the bobsleigh track, and

the hydro project began producing power in Au-

gust. Under a purchase agreement with BC Hydro,

the plant will contribute 33,000 megawatt-hours

per year to Canada’s supply of clean electricity.

Threading the Needlethrough an Olympic VenueBuilding a world-class sports track in rugged terrain in time for the

Vancouver Games was a feat of engineering. Building a hydroelectricplant in the same valley was a world-class challenge.

FROM TOP: THE DOWNSTREAM PORTION OF THE HYDROPROJECT. THE PENSTOCK UNDER CONSTRUCTION. THECOMPLETED POWERHOUSE AT THE BASE OF A PRECIPITOUSROCK CUT.

2

Geotechnically Speaking


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On December 22, 2008, the coal ash impoundment

at the Tennessee Valley Authority’s Kingston plant

failed catastrophically after reaching some 80 feet

above natural grade. An estimated 5.4 million cubic

yards of slurried ash flowed rapidly into the adja-

cent Emory and Clinch rivers. Several properties

were damaged beyond repair, a railroad was bur-

ied, and utilities were disrupted.

The impoundment failure is one of the largest land-

based environmental disasters in the United States,

with clean-up costs currently estimated at over $1

billion. The incident prompted the U.S. Environ-

mental Protection Agency (USEPA) to review the

federal regulations that govern the disposal of wet

coal combustion residuals, or CCRs, which are pro-

duced primarily by coal-fired power plants.

In June 2010, USEPA issued a proposed rule con-

taining two regulatory options for comment by

industry and the public. Both options require clo-

sure or retrofits to impoundments, use of compos-

ite liner systems, and much greater emphasis on

groundwater monitoring and structural stability of

the impoundments.

Review of the inventory of wet CCR impoundments

across the United States shows that many of the

existing surface impoundments and ash landfills

are unlined, and many do not possess a dedicated

groundwater protection and monitoring system.

Under the new CCR regulations, impoundments

could require a retrofit of liners and seepage col-

lection and control systems. Different water man-

agement practices during operation are likely, and

some plants may convert to dry handling and dis-

posal of CCRs.

A Thorough Going-Over

USEPA has highlighted the importance of assessing

impoundment structural stability in its new ruling

on the disposal of CCRs. Indeed, surface impound-

ments that cannot demonstrate adequate stability

within 5 years of the effective date of the rule will

be required to close. Golder is responding to the

heightened awareness of CCR impoundment stabil-

ity issues by putting its geotechnical expertise to

work in assessing and mitigating coal ash impound-

ment risks.

Typically, this begins with desktop studies and

walkover inspections to evaluate the condition of

the surface impoundment. Golder recently per-

formed visual inspections of embankment dam

structures for American Electric Power at several of

its ash pond facilities, as part of AEP’s internal risk

management program.

In the initial phase of the project, Golder reviewed

information on the impoundments provided by

AEP, including design, construction and repair re-

cords, prior inspection reports, and instrumentationmonitoring data. Golder personnel then physically

inspected inflow and outflow structures, upstream

and downstream slopes, dam crests and toes, as

well as abutments and groins. Existing monitor-

ing devices, including piezometers, surface water

weirs, dam internal drains, and settlement monu-

ments were examined, and piezometric water

levels, and flows from internal drain outlets and

seepage were measured. After reviewing monitor-

ing data and evaluating the conditions of each im-

poundment, we were able to give AEP site-specificassessments and recommendations.

Insights from Soil Mechanics

In cases where large ash ponds are located on weak

foundation layers close to large bodies of water,

as at TVA’s Kingston facility, a desktop study and

walkover inspection may not shed adequate light

on the potential geotechnical risks, particularly

those involving deep-seated failure mechanisms in

the foundation. The CCR material is also quite dif-

ferent from other soils, in that it has spherical par-

ticles (Figure 1), which form as a result of the high

temperature at which the coal is burned. Theseparticles can take on loose packing arrangements,

and are potentially more susceptible to contraction

during shear. Excess pore water pressures are gen-

erated during shear and can lead to a liquefaction

flow failure similar to that observed at Kingston.

In our years of work on mining and offshore proj-

ects, Golder has evaluated numerous hydraulic fills

using specially developed field, laboratory, and an-

alytical techniques that are rooted in fundamentalsoil mechanics. The research work on liquefaction

performed by Golder’s staff over the last 30 years,

and published in the 2006 text book “Soil Lique-

faction: A Critical State Approach,” by Golder’s Ken

Been and Mike Jefferies, can be applied to the as-

sessment coal ash impoundment stability risks.

Graham Elliott, Rafael Ospina, and Ken Been from

Golder presented one application of this research at

the May 2010 conference of the American Society

of State Dam Safety Officials in West Virginia. They

explained how the so called “state parameter” (see

Figure 2), or difference in void ratio of the material

at its in situ stress and the void ratio on its criti-

cal state line at the same stress level, is a measure

of the degree of brittleness of the material. In this

way, the state parameter can be used to identify

contractant material behavior (with consequent

increased pore water pressure during shear) and

dilatant behavior.

The state parameter has been shown to be a good

predictor of liquefaction susceptibility (induced

by significant contractant shear strains) in a wide

range of hydraulic fills from around the world, and

appears to be applicable to coal ash as well. The

state parameter is best evaluated using a combina-tion of cone penetration testing (with piezocone

and seismic cone), coupled with laboratory tests on

re-constituted samples of the ash to determine the

intrinsic properties and critical state line of the ma-

terial. This approach obviates the normal problems

of obtaining undisturbed tube samples in loose par-

ticulate materials.

When the state parameter evaluation is used in con-

junction with desktop study information and walk-

over inspections, informed decisions can be made

about stability. As industry and regulators respond

to the new ash regulations in the aftermath of

the TVA Kingston failure, dam safety, liquefactionanalysis, and geotechnical design will be important

tools in assessing and mitigating risks.

Experts in soil mechanics and dam

safety help U.S. power producers to

understand and manage the difficult

byproducts of coal combustion.

Out of the Ashes

GRAHAM ELLIOTT AND RAFAEL OSPINA,

ATLANTA, GEORGIA, USA

FIGURE 2: THE STATE PARAMETER,DEFINED AS THE DIFFERENCE INVOID RATIO OF THE MATERIAL ATITS IN SITU STRESS AND THE VOIDRATIO ON ITS CRITICAL STATE LINEAT THE SAME STRESS LEVEL, IS AGOOD PREDICTOR OF LIQUEFAC-TION SUSCEPTIBILITY IN HYDRAULICFILLS, INCLUDING COAL ASH.

From Elliott, G, Ospina, R.I. andBeen, K. 2010. Static liquefactionof hydraulic fills: implications fordesign, construction, operation andsafety of coal ash impoundments.ASDSO SE Region Dam SafetyConference, Charleston, WestVirginia, May 2010.

0.500

1Mean effective stress

V o i d r

a t i o , e

ψ = e - ec

Current void ratio of the soil

Critical State Locus (CSL)

Contractive behaviour

Dilative behaviour

FIGURE 1: SCANNING ELECTRON MICROSCOPE IMAGE OFCOAL ASH PARTICLES.

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Using detailed seasonal data and the

tools of unsaturated soil mechanics,

Golder researchers look to improve theperformance and longevity of soil cover

systems in northern Canada and other

extreme environments.

DELWYN FREDLUND, JASON STIANSON, & TRACY MCARTHUR

SASKATOON, CANADA

Cover systems are commonly placed over waste rock

or tailings to mitigate against adverse environmen-

tal impact in the energy (e.g., uranium) and mineral

mining sectors. The design of a soil cover system

subjected to northern climatic conditions consti-

tutes one of the most challenging soil mechanicsanalysis faced by geotechnical engineers. Increas-

ingly, soil cover systems are used to mitigate the

negative environmental impacts of waste materi-

als, particularly for waste containment facilities and

remediation of contaminated sites. The concept of

a cover system is straightforward; however, there

are substantial challenges that arise with respect to

design details. Assumptions associated with the de-

sign process can significantly influence the outcome

of the cover design.

In Golder’s work designing cover systems for waste

rock and tailings from mining operations, we are

investigating the complex effects of climate on soilcover design. Our recent study of the several sites

across northern Canada shows that the frozen win-

ter months contribute significantly to the total an-

nual precipitation and water balance at a site.

Elements of a cover system

A soil cover system can be viewed as a thin interface

placed between the atmosphere and the underlying

material strata (Fig. 1). The ground surface either

has moisture coming down in the form of precipita-

tion or going up in the form of evapotranspiration.

To design a cover system, it is necessary to be able

to predict moisture fluxes in and out of the ground

surface, as well as moisture fluxes through the un-saturated soils comprising the cover system. All

elements of that system--atmosphere, cover, and

underlying soils--are highly variable, making the

quantification of the moisture flux boundary condi-

tions challenging.

The first designed cover systems generally consist-

ed of compacted clays. The intent was to construct

a relatively impervious cover overtop of waste ma-

terials. However, with time, the clay covers became

cracked and permeable to the influx of water. The

newer generation of “store and release” cover

systems buffers the effects of extreme climate by

storing water during wet periods and releasing itback to the atmosphere during dry periods. A wide

variety of materials can be used for the cover sys-

tem and the cover

may consist of one,

two or more layers

sandwiched to-

gether to optimize

performance (Fig.

2). The cover mate-rial must be able to

provide sufficient

water storage ca-

pacity and water

release capacity to

accommodate the climatic weather patterns likely

to occur at any time of any year, so the performance

of the cover has to be simulated using past climatic

data, preferably 10 or more years’ worth.

Challenges of northern climates

Soil covers were first designed for regions where

the average annual temperatures were relatively

high and the winter season involved litt le or no frostaction. However, the climatic conditions in northern

Canada are vastly different than those in temper-

ate climatic regions, requiring a revisiting of the as-

sumptions associated with cover design.

To refine our soil cover design models, Golder has

been looking in more detail at northern Canada’s

annual cycle, which can be divided into several dis-

tinct climatic periods: a winter or “inactive” period

that starts at the end of autumn, and an “active”

period that is introduced by the spring thaw period

and continues through the summer growing season.

The physics of moisture flow and water balance at

the ground surface has special conditions attachedfor each of these periods.

The active period is the primary period over which

the numerical modeling is usually performed for

cover design purposes. This is the period for which

infiltration and evaporation can most accurately be

simulated. It is also the period where precipitation

and evaporation are most active. In many cases, the

summer season is the only season of the year that is

simulated using numerical modeling.

However, assumptions made regarding the other

periods of the year can have a significant effect

on the final design. Recent research by Delwyn

Fredlund, Jason Stianson, and Tracy McArthur has

focused on the modelling assumptions associated

with the inactive period and the spring thaw. Dur-

ing the inactive period, the air temperature falls be-

low 0 degrees C and the soil freezes to a depth of

2 or more meters, remaining frozen for about 6 to 7

months. The soil remains relatively dormant while

snow accumulates on the ground surface. During

the spring thaw period, water from the snow melts

and enters the soil or runs off. Given the amount

of annual precipitation in the form of snow, 30%

to 50% of total precipitation, assumptions made re-

garding spring melt and its assimilation at the soil

surface significantly affect the annual water balance

calculations in the soil cover.

Significance of seasons

To evaluate the relative significance of each peri-

od, Golder’s team analyzed 38 years of climatic re-

cords at a site near latitude 48 degrees in Canada.

We found that the empirical assumptions related

to the inactive period can significantly influence

the overall outcome of numerical model results.

Analysis of the annual precipitation showed that

on average, 38.4% of the total precipitation came

during the inactive period, while 61.6% of theprecipitation occurred during the active period.

Soil covers: better solutions to buryingproblem wastes

continued on page 5

AT LEFT: A COVER SYSTEM VIEWEDAS THE INTERFACE BETWEEN AWASTE MATERIAL AND THE CLIMATICENVIRONMENT. BELOW: A SOILCOVER SYSTEM OVER MINE TAILINGSAT A SITE IN CANADA.

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These results reinforce the importance of being able

to more accurately understand the physical process-

es associated with the inactive period of each year.

Potential evaporation calculations performed for

the same 38-year period showed that, on average,

16.1% of the potential evaporation occurred dur-

ing the inactive period, while 83.9% of the poten-

tial evaporation occurred during the active period.

Moreover, the climate was shown to vary substan-

tially from one year to the next making it necessary

to take climatic variations into account.

Potential versus actual

Potential evaporation quantifies the amount of water

that can evaporate from an open pan of water; how-

ever, it is the “actual evaporation”, AE, from the soilsurface that is required in cover design. The sun can

be visualized as pulling water upward while the soil

attempts to retain the water. Consequently, there is a

struggle between the net radiation from the sun and

the suction (negative pore-water pressure) in the soil.

Analyses to compute net moisture flux conditions at

the ground surface were not part of historical soil

mechanics. However, these calculations form an

important part of the application of unsaturated

soil mechanics and are a requirement for Soil Cover

design. The calculation of net moisture flux at the

ground surface involves numerous assumptions and

extensive computer simulations. The ground surfaceforms a moisture flux boundary in the sense that wa-

ter is either entering the ground surface in the form

of precipitation or it is leaving the ground surface

through (actual) evaporation, AE, or evapotranspira-

tion, ET. Water may also be shed through runoff, R.Each of these quantities must be determined over

a period of many years as part of the cover design

methodology.

Golder engineers have been involved in numerous

studies that require the calculation of the water bal-

ance at ground surface as part of the design or evalua-

tion of soil cover systems. We believe that it is possible

to compute design values for “actual evaporation” at

the ground surface as well as provide an estimate

for the transpiration associated with vegetation on

ground surface. The calculations involve the solution

of nonlinear partial differential equations for heat and

water mass movement. While these computations arecomputationally demanding, we believe that we are

at the frontier in applying numerical modelling simu-

lations to cover design.

Golder’s research suggests that there needs to be

further study of the assumptions and procedural

steps associated with the engineering design proto-

col for soil covers in northern Canada. Engineering

design procedures have emerged for active period

of each year; however, there needs to be further at-

tention given to numerical simulation of the winter

and spring periods. By refining our assumptions

about local climate and the resulting fluctuations of

moisture at the ground surface, we can improve theperformance and longevity of soil cover systems in

extreme environments.

SOIL COVERS CONTINUED FROM PAGE 4

Ashlu Creek hydroelectricproject earns award of merit

Golder Associates Ltd. and project partners RSW

inc. and Hatch Mott MacDonald were recognized

with an award of merit by the Consulting Engineers

of British Columbia (CEBC) for technical excellence

and innovation on the run-of-river Ashlu Creek

Hydroelectric Project. Rich Humphries, Paul Schlot-feldt, Charlie Harrison, Tammy Shore, and Cortney

Palleske were the key members of the Golder team

that completed detailed, fast-track engineering for

the project, which will supply enough electricity for

24,000 homes each year in British Columbia.

It was one of 13 awards in five categories present-

ed at CEBC’s gala event in April 2010. One Award

of Excellence and at least one Award of Merit are

presented annually in five categories: buildings;

municipal; transportation; natural resource, energy

and industry; and soft engineering.

Dennis Becker honoredwith R.F. Legget Medal

In September 2010, Dennis

Becker, Principal and Senior

Geotechnical Specialist in

the Calgary, BC office, won

the Canadian Geotechni-

cal Society’s R.F. Legget

Medal. Dennis received a

standing ovation from the

500 attending delegates as

he accepted the top honor from the geotechnical

community in Canada.

The prestigious R.F. Legget Medal is presented

annually to an individual who has contributed

achievements of permanent significance to the

field of geotechnical engineering in Canada, and to

the development of an understanding of the inter-

relationship of civil engineering and engineering

geology in Canada.

Past winners include Victor Milligan, John L. Sey-

chuk, Norbert R. Morgenstern, Jack Clark, Del

Fredlund and David M. Cruden.

Earlier in 2010 Dennis also won the Julian C. Smith

Medal for “engineering achievement in the devel-

opment of Canada” from the Engineering Instituteof Canada (EIC), which represents all engineering

disciplines.

News from Golder’s Ground Engineering Group

Golder helps to re-openkey road around Gibraltar

In February 2002, a major rockfall at the northern

portal of Dudley Ward Tunnel resulted in the death of

Brian Navarro, a driver exiting the tunnel at the time.

The tunnel, which completed a ring road around theRock of Gibraltar, was immediately closed until an

investigation of the rockfall fatality was undertaken.

Golder was commissioned by the Government of Gi-

braltar to conduct a rock fall risk assessment, which

identified a need to upgrade the existing rockfall

protection measures at the tunnel portal prior to the

road being re-opened to the public.

In December 2008, Golder was authorized to pro-

ceed with the detailed design of the upgrades, which

included a rockfall canopy of

100m extending from the rock

tunnel portal; construction of

400m of high-capacity catchfences on the northern approach

road to the tunnel; and demoli-

tion of the windy single line road

and adjacent structures to allow

construction of a new improved

two-way highway.

Stewart Lightbody and Bruce

Cheesman of the Maindenhead

office led the Golder effort. The design team in-

cluded Clark Smith Partnership, who led the high-

way and structural design, and HBS Consulting who

carried out the associated mechanical and electrical

design.

In addition to this core project, Golder was com-

missioned to carry out a road-widening plan at the

approach of Dudley Ward Northern Approach Road.

This included soil nailing and shotcreting around the

East-West Admiralty Tunnel, as well as upgrading

and maintenance of the unlined 720m long rock tun-

nel and the southern portal.

Despite the severe restraints placed on Golder, the

£10.6m projects were completed within budget on

November 1, 2010, allowing the re-establishment of

a route all around the Rock.

An official opening took place on

November 2, 2010 by the Chief

Minister of Gibraltar, Peter Ca-

ruana. Stewart Lightbody and

Bruce Cheesman were invited

to attend the opening ceremony

(photo at left). The section of

road from the Dudley Ward Rock

Tunnel to the East-West Admiral-

ty/ComCen Tunnel was renamed

Brian Navarro Way in memory of

the tragic loss.

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Krzewinski takes helm of ColdRegions Development Studies

Tom Krzewinski, Principal

and senior geotechnical

engineering consultant in

Golder’s Anchorage, Alaskaoffice, was named president

of the International Associa-

tion of Cold Regions Devel-

opment Studies (IACORDS).

During his 6-year term, he

will oversee IACORDS as it

focuses on organizing symposiums for experts to

exchange ideas on scientific, technological, and

cultural expertise toward the development of cold

regions.

Tom has been with Golder since 2002 and has over

37 years of experience as a geotechnical, envi-

ronmental, and cold regions engineer. He was in-strumental in the design and construction of the

Trans Alaska Pipeline System (TAPS) and was the

1998 recipient of the the American Society of Civil

Engineers (ASCE) Harold R. Peyton Award for sig-

nificant contributions to the field of cold regions

geotechnical engineering. He is the Alaska Engi-

neering Societies’ 2009 Engineer of the Year, and

winner of the 2010 Can-Am Civil Engineering Am-

ity Award in recognition for his many years of ex-

emplary geotechnical engineering in the northern

U.S. and Canada.

Tom is past chair of ASCE’s Technical Council on

Cold Regions Engineering and past president of the

Alaska Section of ASCE. He served for 12 years

on the IACORDS Board of Directors and will chair

the organization’s next symposium, ISCORD 2013,

which will be held in Anchorage.

Paul becomes first Australianwinner of Wolters’ Prize

Associate Darren Paul from

Golder’s Melbourne, Austra-

lia office has won the cov-

eted Richard Wolters’ Prize

for engineering geology.

The prize recognizes merito-rious scientific achievement

by a young professional and

is awarded by the Interna-

tional Association for Engi-

neering Geology and the Environment (IAEG).

Named for the late Dr Richard Wolters, a past Sec-

retary General of IAEG, the prize has been awarded

biannually since 1986, making Darren the tenth re-

cipient and the first ever Australian winner.

In 2008, Darren was named the Young Profes-

sional Engineer of the Year by Engineers Australia

Victoria Division. Among his notable achievements

is his work as Geotechnical Project Manager forthe world’s tallest building, the Nakheel Tower in

Dubai, UAE.

Elmer et al author newguidebook to old tunnels

The tunnelling expertise of Richard Elmer, senior

geotechnical specialist in Golder’s Chelmsford, UK

office, is featured in the Construction Industry Re-

search and Information Association’s publication,“Tunnels: inspection, assessment, and mainte-

nance.” Part of CIRIA’s collection of best practice

guides, the publication discusses the assessment,

condition appraisal, maintenance, and repair of

the structural elements of existing tunnels, with

a focus on older infrastructure and the construc-

tion materials of the era. Richard was one of three

primary consultants on the publication, which con-

tains over twenty case studies from recent tunnel-

ling works. More information at www.ciria.org

Trevor Carter and Davide Elmo, winners of the

2009 and 2010 Victor Milligan awards for the

best Golder paper on ground engineering, were

honored at Golder’s 2010 Global Principals

Meeting held in October in Vancouver, BC.

The 2010 Milligan Award

went to block cave min-

ing expert Dr. Davide

Elmo of the Burnaby, BC,

Canada office. Davide

and coauthor Doug Stead

of Simon Frazer Universi-ty published the winning

paper, An Integrated Numerical Modelling-

Discrete Fracture Network Approach Ap-

plied to the Characterisation of Rock Mass

Strength of Naturally Fractured Pillars, in

the international journal Rock Mechanics and

Rock Engineering in January 2009.

Estimating rock mass strength is a challenging

proposition in most rock engineering designs and

applications. Davide’s paper describes a method

of numerical modeling of fractured mine pillars

that uses an integrated finite element/discrete

element- discrete fracture network approach tosimulate rock mass failure. This approach makes

it possible to study the failure of rock masses

in tension and compression, along pre-existing

fractures, and through intact rock bridges. The

simulation also allows the generation of complex

kinematic mechanisms that can dictate potential

failure paths in rock masses.

Davide’s paper was one of the 41 papers sub-

mitted by Golder staff in response to the call for

paper submissions in early 2010. Runners-up in

this year’s competition were “Stability of Large

Thickened, Non-Segregated Tailings Slopes” by

A.L. Li, K. Been, D. Ritchie, and D. Welch (second

place), and “Characterisation of Natural Frag-

mentation Using a Discrete Fracture Network

Approach and Implications for Current Rock

Mass Classification Systems” by D. Elmo, S. Rog-

ers, and D. Kennard (third place).

As part of the award, Davide will present this

paper at a number of Golder Associates offices,

web meetings, and learned society meetings.

Also receiving his award

was the 2009 Milligan

honoree, Trevor Carter,

a Principal in the Missis-

sauga, BC, Canada office.Trevor and his coauthors,

Joe Carvalho of Golder’s

Mississauga office and

Mark Diederichs of Queen’s University, published

their winning work, the Application of Modi-

fied Hoek-Brown Transition Relationships

for Assessing Strength and Post-Yield Be-

haviour at Both Ends of the Rock Compe-

tence Scale, in the June 2008 edition of the

Journal of the Southern African Institute of Min-

ing and Metallurgy.

Award History

2010 was the sixth year of the award, which

was named for Golder cofounder and interna-

tionally known ground engineer Victor Milligan

(1929-2009). Past winners include Chris Haber-

field (2005), Nick Shirlaw (2006), Rodolfo San-

cio (2007), Joe Carvalho (2008), Trevor Carter

(2009), and Davide Elmo (2010).

In 2004, Golder’s Ground Engineering Group

honored Vic with the creation of the Victor Mil-

ligan Award, given annually at Golder to the

principal author of the best published paper on

a ground engineering topic. The award will con-

tinue to be given out annually in memory of Vic’s

outstanding contributions to the geotechnical

community within Golder and internationally.

2009 and 2010 Milligan awards presented

News from Golder’s Ground Engineering Group

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7/7

© 2011, GOLDER ASSOCIATES CORPORATION. GOLDER, GOLDER ASSOCIATES, ANDTHE GLOBE DESIGN ARE TRADEMARKS OF GOLDER ASSOCIATES CORPORATION.

Wind projects have taken Golder geotechs to

all parts of the globe. (Left) The 128 turbines of

the Waubra Wind Farm harness the wind of the high

plateaus of southeastern Australia. Golder’s work

for Acciona Energy on the largest operating renew-able power project in the Southern Hemisphere in-

cluded geotechnical investigation and design for the

massive turbine footings (Right and on the cover)

For the Dokie Wind Project, Golder undertook a pro-

gram of geotechnical exploration and design that

had teams scrambling across miles of rocky terrain

near Chetwynd, British Columbia.

Going Where the Wind Blows

An EU research project tests feasibilityof keeping carbon dioxide out of the

atmosphere by storing it underground.

CO2 Emissions: Is it Sink or Swim?

CO2SINK is a research project on the storage of

CO2 in an underground geological formation near

the town of Ketzin, west of Berlin. The project is

funded by the EU Commission, the Federal Min-

istry of Economics and Technologies (BMWi),

the Federal Ministry of Education and Research

(BMBF), and industry partners. It aims to develop

the basis for storage technology by injecting CO2

into a saline aquifer, following its fate over long

periods of time, evaluating reservoir stability and

integrity.

Cristian Enachescu and Philipp Wolf

of Golder’s Celle, Germany office led the project

team responsible for the small scale (wellbore

and near-wellbore) and large scale (geologicalformation) hydraulic reservoir characterization.

Data from the hydraulic testing program (pictured

above), which included drill stem tests, produc-

tion tests, injection tests, and interference tests

in three ~750 m deep boreholes, was used to

develop the conceptual hydraulic and boundary

model of the reservoir.

The CO2SINK project started in April 2004, and

injection of CO2 began June 30, 2008. Since then,

more than 44,329 tons of CO2 have been injected

uderground.

FROM TOP: GOLDER’S HYDRAULIC TESTING PROGRAMAT KETZIN. DIAGRAM OF THE CO2 SEQUESTRATIONMODEL BEING TESTED (COURTESY CO2SINK.ORG).

About Geotechnically Speaking

Developed by Golder’s Ground Engi-neering Group, Geotechnically Speak-

ing showcases innovative and technically

challenging geotechnical projects that Golder

professionals have worked on throughout the

world.

Issue 5: Ground Engineering Group Lead-

er and Managing Editor: Paul Schlotfeldt.

Editorial and Production Support: Kathryn

Haines

About Golder Associates

At Golder Associates we strive to be the most

respected global group specializing in ground

engineering and environmental services.

Employee owned since our formation in 1960,

we have created a unique culture with pride

in ownership, resulting in long-term organiza-

tional stability. Golder professionals take the

time to build an understanding of client needs

and of the specific environments in which they

operate. We continue to expand our techni-

cal capabilities and have experienced steady

growth, now employing over 7,000 people

who operate from more than 160 offices lo-

cated throughout Africa, Asia, Australasia, Eu-

rope, North America and South America.

7


Documents

Geotechnically Speaking.issue 5