PND Engineers, Inc., founded in 1979, is a
full-service consulting engineering firm
that provides civil, marine, geotechnical,
structural, and construction inspection
services for a wide variety of projects. Our
Arctic and cold regions design experience
ranges from the Russian and Canadian
Arctic regions, and throughout Alaska, for
more than 30 years.
P
N
D
E N G I N E E R S , I N C.
Headquarters:
Anchorage Office
Juneau Office
Seattle Office
1506 West 36th Avenue
9360 Glacier Highway, Suite 100
1736 Fourth Avenue S, Suite A
Anchorage, Alaska 99503
Juneau, Alaska 99801
Seattle, Washington 98134
Phone: 907.561.1011
Phone: 907.586.2093
Phone: 206.624.1387
Fax: 907.563.4220
Fax: 907.586.2099
Fax: 206.624.1388
Fort Collins Office
Palmer Office
141 S College Avenue, Suite 101
550 S Alaska St., Suite 207
Fort Collins, Colorado 80524
Palmer, Alaska 99645
Phone: 970.797.2101
Phone: 907.707.1081
Fax: 970.631.8942
PND Engineers Canada, Inc.
Vancouver Office
Oceanic Plaza
20th Floor, 1066 West Hastings St.
Vancouver, BC Canada V6E 3X2
Phone: 604.601.5247
For additional information please visit our website.
www.pndengineers.com
c Copyright 2013, PND Engineers, Inc.
B R I D G E A BU T M E N T S AC C E S
S U R V E Y H E AV Y- L O A D FA C I L
B R I D G E S ARCTIC
SHIPPING TERMIN
P I E R S H Y D RO L O G Y C AU S E W
P E R MENGINEERING
AFROST PREDRILLING
DOLPHINS FENDER SYSTEM
BULKHEADS ENVIRONMENT
I M PA C T S T U D I E S S I T E D E V E
B R I D G E A BU T M E N T S AC C E S
S U R V E Y H E AV Y- L O A D FA C I L
BRIDGES SHIPPING TERMIN
P I E R S H Y D RO L O G Y C AU S E W
PREDRILLING DOLPHINS F
SYSTEMS BULKHEADS ENVI
I M PA C T S T U D I E S S I T E D E V E
B R I D G E A B U T M E N TPS N
A CD
CES
I N E E R S , I N C.
S U R V E Y H E AV Y- L OEAN GD
FA C I L
P N D
ARCTIC STRUCTURES DESIGN
E N G I N E E R S , I NC.
PND’s Alaskan roots have enabled the firm to be at the forefront of
Arctic engineering. Working in the world’s Arctic regions requires
more than traditional engineering skills. Special obstacles created
by the climatic, geological, and logistical conditions of the Arctic
and subarctic require knowledge and techniques that are
rarely encountered in conventional engineering. PND’s vast
Arctic experience enables us to deal with the challenges of
design, construction, and operations in Arctic regions of the world.
Our expertise in this field covers many aspects of engineering, ranging
from building and bridge design to site civil and geotechnical design. It
includes the design of Arctic marine facilities and offshore drilling
islands. It also involves Arctic hydrology studies and permafrost
foundation design, as well as ice-structure interaction. We routinely
design for severe environmental conditions, including heavy snow
loads, both continuous and discontinuous permafrost, ice interaction
loads, and extreme temperatures. PND’s broad Arctic experience has
emphasized the importance of dealing with a host of critical issues
such as cold-temperature material toughness; the effects of spring
break-up on rivers for both flooding and bridge design; remote access
utilizing ice roads and pads; and construction logistics associated with
the Arctic.
PND has successfully completed projects in the Arctic and subarctic
areas of Alaska, Canada, and northern Russia. Schedules and quality
have been tightly maintained despite extremes in weather and
logistical conditions. Our Arctic experience is underscored by a
“can-do” attitude regardless of any technical, extreme
environmental, or logistical problems. Since the founding of the
company, PND has provided professional services tailored to the
needs and schedules of its clients, utilizing state-of-the-art
technology and skills. Many of our Arctic projects have won
prestigious awards for their innovative design and construction,
including the West Dock Causeway and Endicott Causeway breaches;
Kuparuk River Bridge and Low Water Crossing; the Oliktok Point
Dock; and pile foundations in permafrost for the Napaaqtugmuit
School in Noatak, Alaska.
Drill Rig 6 | North Slope, Alaska
Kuparuk Pipe Restraint Tower | North Slope, Alaska
PND designed this award-winning, four-story restraint tower
built to stabilize an oilfield separator by devising a remarkably
stiff, axially-loaded structure where deflection from bending
stress is virtually eliminated. Using high-grade, 48-inchdiameter surplus pipeline pipe from the Trans-Alaska Pipeline, a
48-foot-tall, two-legged, welded pipe structure was developed
that would transmit loads axially to a frozen foundation.
Dubbed a bi-pod, the structure utilized a massive prefabricated
steel weldment as a cap to which the crude oil piping system was
anchored. This innovation earned a Lincoln Arc Welding
Bronze Award.
PND designed all structural framing for a new drill rig on the
North Slope of Alaska, which at the time was reported by the tire
manufacturer to be the largest rubber tire vehicle in the world. At
more than 3 million pounds, Drill Rig 6 utilizes welded steel
components, including a backbone of twin 6-foot by 10-foot box
girders to form a self-mobilizing unit. This project won a Lincoln
Arc-Welding Award for Best of Program.
The rig is capable of moving at speeds of 2.5 mph in both
longitudinal and transverse directions. This mobility is made
possible by six sets of hydraulic drive bogies, each of which has
twin 11-foot-diameter rubber tires. Each bogie is capable of
supporting a load of 300 to 400 tons.
Napaaqtugmiut School | Noatak, Alaska
PND provided civil and structural engineering design for this single-story, 50,000-square-foot building, including cafeteria, gymnasium,
and two classroom wings for grades K-12. PND designed a pile foundation for the structure in permafrost soils. The building is
elevated above the permafrost to prevent thawing of marginally frozen soils. Significant consideration was given to developing a
lightweight structure, since all materials had to be flown in to the site. The remote location made clarity of design and ease of
construction critical for this project. The structure was built with steel-braced frames designed to resist lateral wind and seismic loads.
PND | Arctic Engineering
RESEARCH & DEVELOPMENT
OIL & GAS DEVELOPMENT
Pile Testing In Permafrost Soil
PND performed long-term pile creep tests in Alaska’s Arctic region. Twelve piles were tested in gravelly and silty permafrost
soils. These tests characterized the adfreeze bond developed by a new pile installation process that is considerably more
economical than traditional Arctic pile installation procedures. The testing system applied pile loads of more than 800,000
pounds and was designed for remote use to function autonomously, keeping a constant load without manpower for maintenance.
Northstar Offshore Island | Prudhoe Bay, Alaska
PND provided design services for the Northstar oil drilling and production island in the Beaufort Sea over two phases. The first phase
consisted of a 320-foot by 140-foot OPEN CELL SHEET PILE dock with fenders, foundations, and various structural elements at
the south end of the island. The dock was built in two separate halves with a central trench section to allow the installation of
pipelines onto the island. The pipeline transition trench was later closed by a sheet pile closure wall, resulting in a solid dock face.
Other aspects included heliport design; foundation design for the processor, compressor, turbine and fuel tank buildings; budgetary,
administrative, project management and alliance support; and design services for temporary island access during the first year of a
two-year construction program.
During the second phase of the project, PND developed, reviewed, and tested new shore protection alternatives for the island,
including an OPEN CELL SHEET PILE perimeter wall and rock berm alternatives. The PND effort included extensive and
simultaneous physical and numerical modeling to test and refine concept alternatives and ensure accuracy. The work included physical
modeling in wave tanks at Oregon State University and Texas A&M University, as well as physical modeling of ice effects in tanks in
Newfoundland and Finland. Computer modeling included ice simulations, CGWAVE and COBRAS wave modeling, and structural
finite element modeling.
Additionally, as part of an enhancement project, PND designed an enlarged sheet pile-protected area for a new operations
center/living quarters, a high-capacity module barge dock designed for 4,300-ton module offload, seawater intake and sump, offshore
dredging, and an ARKTOS emergency vehicle egress ramp. The scope included concept through final design, permitting, assistance,
physical/numerical modeling of wave/ice interaction, cost estimating, constructability reviews, construction inspection/QA, and
project management.
PND | Arctic Engineering
Wave Tank and Ice Tank Physical Models
Ice Beam and Borehole Jack Testing
PND performed a study of mechanical ice strength properties in
the Colville River. A series of tests, including ice beam bending
tests and confined compressive strength measurements using a
calibrated borehole jack, were conducted to establish the bending
and compressive strength as well as mechanical characteristics of
the ice for design purposes. The test procedures involved jacking a
series of cantilevered beams of ice and pulling upward on the ice
beam to break the ice in a way similar to the expected mode of
failure for design use. The test results were in the anticipated range
and served to validate the design.
Model testing using both numerical (computer) and physical
models are often done for Arctic and ocean structures. PND
has tested designs for Beaufort Sea artificial islands in both 3-D
ice tanks and large wave basins. For one particular project,
slope protection improvements for an existing petroleum
development Arctic island were developed by PND. Both
sloping armor rock and vertical wall steel bulkhead designs
were tested. The island is approximately 1,400 feet across on
the diagonal, in about 40 feet water depth, and was modeled in
ice tank facilities in Finland and Newfoundland. Wave tank
testing was conducted at facilities at Oregon State University
and at Texas A&M University. The physical models helped
answer key questions about the risk of both ice and wave
overtopping, ice behavior, wave deflector design, and the
stability of the armor rock slope protection.
OIL & GAS DEVELOPMENT
ARCTIC BRIDGE & CIVIL DESIGN
Endicott Causeway | Prudhoe Bay, Alaska
With an overall length of 700 feet, this causeway bridge, over a breach in a
previously earth-filled ocean causeway, is supported by two in-water conical
pile-supported piers and features abutments protected by OPEN CELL SHEET
PILE® bulkheads. The breach is designed for up to 38-foot scour below existing
seabed, and the design ice load on the piers is 500 kips. This project won a
Third-Place Bronze Award in the James F. Lincoln Arc Welding Foundation
Professional Awards Program, as well as an Award of Merit in the American
Institute of Steel Construction Competition for Special Purpose Bridges.
Kuparuk River Module Crossing | North Slope, Alaska
Engineered to accommodate module and carrier load
combinations in the range of 2,300 tons and to resist forces
generated by ice floes up to 5.5 feet thick, this North Slope steel
box-girder bridge exhibits one of the heaviest load capacities in the
world for its construction type. Careful design minimized bridge
length, with a 1,500-foot-long paved low water roadway section
designed to withstand overflow during flood events without
damage. The bridge utilizes OPEN CELL SHEET PILE bulkhead
abutments and won First Place in Alaska Construction & Oil
magazine’s “Heavy Construction Project of the Year” contest, and
a Bronze Award from the Lincoln Arc Welding Foundation.
PND | Arctic Engineering
Kuparuk River Low Water Crossings |
North Slope, Alaska
PND designed these innovative submersible bridges with
combined paved low water crossings on the North Slope of
Alaska. This design saved the owner approximately 50 percent
($10 million) over the cost of elevated bridges for the crossing
of two river channels in a flood plain nearly two miles wide.
Extreme environmental conditions, design vehicle weights
approaching 4 million pounds, impact loading from river ice 5
feet thick, and discontinuous permafrost soil conditions posed
interesting and unusual design and construction challenges.
The strength, resilience, and construction flexibility of welded
steel were fundamental in providing the most cost-effective
solution for this project. The project won the following: James
F. Lincoln Arc Welding Award, AISC/NSBA Bridge Special
Award, and the Deep Foundations Institute Special
Recognition Award.
Gas Cycling Project Infrastructure Development | North Slope, Alaska
PND was responsible for all of the civil work associated with developing this multi-billion dollar project’s transportation and
infrastructure systems consisting of water access; module off-load marine facilities; a service pier; bridges; gravel and ice roads and
pads; hydrology; upland and bathymetric surveys; met-ocean investigations and associated coastal engineering; airstrip and associated
facilities, including instrument landing systems; all containment, including tank truck and fuel tank farms; water supply; and material
sources. The project is located on Alaska’s North Slope near the Arctic National Wildlife Refuge (ANWR) and is underlain by
permafrost 2,000 feet deep throughout the project site.
© JUDY PATRICK
Liberty Island Offshore Development | North Slope, Alaska
PND led the civil team for this North Slope development, which evaluated geotechnical data; identified material sources; utilized
aerial photography for road and bridge layout; conducted hydrology and hydrological studies, met-ocean studies, and sea ice
encroachment studies; developed design ice criteria; engineered road and pipeline bridge designs; and assisted in environmental
and cultural/archaeological studies for various project development alternatives.
The alternative selected for construction involved an expansion of an existing offshore drilling pad utilizing 2,000 feet of OPEN
CELL SHEET PILE shore protection in up to 10 feet of water and the replacement of an existing bridge’s superstructure. The
island expansion and barge dock were designed for very heavy oilfield drill rig loads and self-propelled module carrier loads to
support the planned ultra-extended-reach drill rig equipment (longest in the world, and largest). PND also designed the conductor
piles and well cellar lids that were specialized for the very high loads and particular needs of this development. PND provided
construction inspection, QA and management of the construction of the island expansion, gravel material source development,
and existing bridge demolition and replacement.
MARINE DESIGN
ARCTIC BRIDGE & CIVIL DESIGN
Red Dog Road | Kotzebue, Alaska
Port Facilities | Nome, Alaska
PND has designed four separate waterfront structures around
City of Nome property. Three of these are dock facilities, each
approximately 200 feet long. These structures are designed to
withstand and be overrun by 4-foot-thick sea ice floes (see
above) and resist 16-foot waves.
Oliktok Point Dockhead and Dolphins | North Slope, Alaska
One of the largest docks north of the Arctic Circle, this sheet pile wall structure is capable of resisting ice forces greater than 140
kips per foot of wall, and it was designed to accommodate the loading footprint developed by a 2,350-ton module and carrier. The
offshore mooring dolphins, the first of their kind used offshore in Alaska, resist forces generated by 400-foot barges, as well as those
from infinite ice sheets up to 6 feet thick. Special Alaska-manufactured revetments protect critical areas around the dock and
approach roadway during extreme wave movements. The project won several awards, including a Third Place Award from the Lincoln
Arc Welding Foundation, and a Merit Award from Alaska Construction & Oil magazine.
PND | Arctic Engineering
This road is in northwestern Alaska, about 80 miles north of
Kotzebue, and extends approximately 54 miles from the coast
of the Chukchi Sea to the Red Dog Mine, one of the world’s
largest and richest lead and zinc mines. Based on in-depth
analysis, PND designed a road alignment that maintained close
proximity to borrow sources, minimized the number and size
of stream crossings required, and provided the best available
foundation. Although the majority of the route traverses
frozen soils, which become weak when thawed, the finished
road safely conveys 1,600-ton modules and large ore carriers
year-round. This was accomplished by way of a combination
of gravel and high-strength geotextile fabric.
West Dock Causeway | North Slope, Alaska
PND earned a Silver James F. Lincoln Arc Welding Foundation
Award for its design of the West Dock Causeway breach bridge
on Alaska’s North Slope. The structure is a single-lane, torsionally
resistant steel box-girder bridge with a 700-foot-long, four-span
main bridge and 80-foot-long, single-span approach trestles at
each end, for an overall length of 900 feet. The vertical piers are
supported by eight 36-inch-diameter batter piles designed to
resist ice loads of up to 1,200 kips with 40-foot scour.
CD-4 Road | North Slope, Alaska
PND provided engineering and construction oversight for construction of this 3.8-mile gravel road and 10-acre gravel drill pad
located within the Colville River Delta. This facility lies within the Colville River Unit on the North Slope of Alaska and is located on
permafrost in a large river delta. PND’s design efforts included optimizing the road route with analysis of aerial photography and field
investigations in order to minimize exposure to the annual spring floods and impacts to the surrounding tundra habitat. In addition
to the facility’s operational requirements, the project’s design considerations include thermal protection of the permafrost, integration
and protection of the facility within a complex floodplain, and coordination with federal, state, and local permitting efforts.
MARINE DESIGN
ARCTIC BRIDGE & CIVIL DESIGN
Kuparuk Runway Upgrades | North Slope, Alaska
PND provided engineering design, permitting support, construction planning, and construction inspection services to substantially
upgrade the existing gravel runway at Kuparuk with subbase improvements, runway extensions, asphalt pavement, in-pavement
centerline and touchdown zone lighting, new edge lighting, new MALSR approach lighting, all new instrument landing systems (ILS)
and weather systems, five new equipment shelters, and a new air traffic coordination building in order to accommodate the needs of a
new fleet of Boeing 737 aircraft and improve safety of the facility. This project was complex in that the runway is founded upon
permafrost, and thermal analysis was an important aspect of the project because the design needed to ensure long-term stability of the
embankment. As part of these design services, several alternative project configurations were developed, including runway, taxiway,
and apron expansions, runway relocation, obstruction mitigation and/or relocation, airport lighting alternatives, and ILS alternatives.
Our design conformed to the latest industry practices as specified by the Alaska DOT&PF, AASHTO, and the FAA.
Hope Bay Mine Site Development | Hope Bay, Nunavut, Canada
PND performed studies of port facilities, access roads, bridges, fill pads, module staging, upland tank farm storage, shipping logistics,
and airport facilities for the Hope Bay Gold Mine project. The project is located in the Canadian Arctic, requiring consideration of
ice forces on dock facilities and design of transportation infrastructure on ice-rich permafrost terrain. PND designed an OPEN
CELL SHEET PILE jetty to serve as a supply berth, allowing transport of large modules in excess of 2,000 tons. Upland mooring
points and camp barge access floats were also evaluated as part of the design process.
Cook Inlet Ice Studies | Alaska
CD3 Pipeline Bridges | North Slope, Alaska
PND was responsible for design and construction oversight of
three pipeline bridges located in the Colville River Delta. All
bridges were two-span steel box structures with lengths of 455
feet to 690 feet. The center pier was designed with an inclined
face to resist ice floes approaching from various angles. Since
2006 PND has performed the biennial inspections of these
structures and provided detailed inspection reports outlining
recommended maintenance.
PND | Arctic Engineering
Tarn, Meltwater, and Palm Field Development |
North Slope, Alaska
For the Tarn Field project, PND designed seven ultra-high-loadcapacity steel bridges over several small North Slope streams.
Extreme environmental conditions, design vehicle weights
approaching 2,000 tons, and permafrost soil conditions posed
design and construction challenges. These structures have played
a critical role in providing drill rig access at accelerated schedules,
with construction occurring only within the three-month ice road
season. The designs utilized innovative OPEN CELL SHEET
PILE abutments and piles founded in permafrost. Bridge lengths
range from 40 feet to 120 feet.
PND has been responsible for numerous marine projects in Cook Inlet that have
required general and site-specific ice studies and monitoring. Some of these projects
include: Port MacKenzie deep draft and fill docks, the Knik Arm Bridge development,
the Cook Inlet Ferry Landings, and the Chuitna Coal project.
Cook Inlet tides produce fast-moving tidal currents exceeding 3 feet per second. These
tidal currents carry typical 2-foot-thick ice floes in excess of 1,000 feet long with
occasional rafted floes twice that thickness. Loads on piles can exceed several hundred
thousand pounds, and revetments with 3- to 4-foot-diameter keyed armor rock have
been severely plowed from large floes.
PND has provided ice monitoring, including: measurement of ice forces on strain gauge
instrumented dolphin structures, ice thickness measurements, salinity and silt
measurements, 4-foot sample flexural tests, and current studies to determine flow patterns,
as well as provided numerous site observations. PND reviewed one year of web camera
footage, producing a timelapse movie of the ice floes around the port of Anchorage.
MARINE DESIGN
ARCTIC BRIDGE & CIVIL DESIGN
Kuparuk Runway Upgrades | North Slope, Alaska
PND provided engineering design, permitting support, construction planning, and construction inspection services to substantially
upgrade the existing gravel runway at Kuparuk with subbase improvements, runway extensions, asphalt pavement, in-pavement
centerline and touchdown zone lighting, new edge lighting, new MALSR approach lighting, all new instrument landing systems (ILS)
and weather systems, five new equipment shelters, and a new air traffic coordination building in order to accommodate the needs of a
new fleet of Boeing 737 aircraft and improve safety of the facility. This project was complex in that the runway is founded upon
permafrost, and thermal analysis was an important aspect of the project because the design needed to ensure long-term stability of the
embankment. As part of these design services, several alternative project configurations were developed, including runway, taxiway,
and apron expansions, runway relocation, obstruction mitigation and/or relocation, airport lighting alternatives, and ILS alternatives.
Our design conformed to the latest industry practices as specified by the Alaska DOT&PF, AASHTO, and the FAA.
Hope Bay Mine Site Development | Hope Bay, Nunavut, Canada
PND performed studies of port facilities, access roads, bridges, fill pads, module staging, upland tank farm storage, shipping logistics,
and airport facilities for the Hope Bay Gold Mine project. The project is located in the Canadian Arctic, requiring consideration of
ice forces on dock facilities and design of transportation infrastructure on ice-rich permafrost terrain. PND designed an OPEN
CELL SHEET PILE jetty to serve as a supply berth, allowing transport of large modules in excess of 2,000 tons. Upland mooring
points and camp barge access floats were also evaluated as part of the design process.
Cook Inlet Ice Studies | Alaska
CD3 Pipeline Bridges | North Slope, Alaska
PND was responsible for design and construction oversight of
three pipeline bridges located in the Colville River Delta. All
bridges were two-span steel box structures with lengths of 455
feet to 690 feet. The center pier was designed with an inclined
face to resist ice floes approaching from various angles. Since
2006 PND has performed the biennial inspections of these
structures and provided detailed inspection reports outlining
recommended maintenance.
PND | Arctic Engineering
Tarn, Meltwater, and Palm Field Development |
North Slope, Alaska
For the Tarn Field project, PND designed seven ultra-high-loadcapacity steel bridges over several small North Slope streams.
Extreme environmental conditions, design vehicle weights
approaching 2,000 tons, and permafrost soil conditions posed
design and construction challenges. These structures have played
a critical role in providing drill rig access at accelerated schedules,
with construction occurring only within the three-month ice road
season. The designs utilized innovative OPEN CELL SHEET
PILE abutments and piles founded in permafrost. Bridge lengths
range from 40 feet to 120 feet.
PND has been responsible for numerous marine projects in Cook Inlet that have
required general and site-specific ice studies and monitoring. Some of these projects
include: Port MacKenzie deep draft and fill docks, the Knik Arm Bridge development,
the Cook Inlet Ferry Landings, and the Chuitna Coal project.
Cook Inlet tides produce fast-moving tidal currents exceeding 3 feet per second. These
tidal currents carry typical 2-foot-thick ice floes in excess of 1,000 feet long with
occasional rafted floes twice that thickness. Loads on piles can exceed several hundred
thousand pounds, and revetments with 3- to 4-foot-diameter keyed armor rock have
been severely plowed from large floes.
PND has provided ice monitoring, including: measurement of ice forces on strain gauge
instrumented dolphin structures, ice thickness measurements, salinity and silt
measurements, 4-foot sample flexural tests, and current studies to determine flow patterns,
as well as provided numerous site observations. PND reviewed one year of web camera
footage, producing a timelapse movie of the ice floes around the port of Anchorage.
MARINE DESIGN
ARCTIC BRIDGE & CIVIL DESIGN
Red Dog Road | Kotzebue, Alaska
Port Facilities | Nome, Alaska
PND has designed four separate waterfront structures around
City of Nome property. Three of these are dock facilities, each
approximately 200 feet long. These structures are designed to
withstand and be overrun by 4-foot-thick sea ice floes (see
above) and resist 16-foot waves.
Oliktok Point Dockhead and Dolphins | North Slope, Alaska
One of the largest docks north of the Arctic Circle, this sheet pile wall structure is capable of resisting ice forces greater than 140
kips per foot of wall, and it was designed to accommodate the loading footprint developed by a 2,350-ton module and carrier. The
offshore mooring dolphins, the first of their kind used offshore in Alaska, resist forces generated by 400-foot barges, as well as those
from infinite ice sheets up to 6 feet thick. Special Alaska-manufactured revetments protect critical areas around the dock and
approach roadway during extreme wave movements. The project won several awards, including a Third Place Award from the Lincoln
Arc Welding Foundation, and a Merit Award from Alaska Construction & Oil magazine.
PND | Arctic Engineering
This road is in northwestern Alaska, about 80 miles north of
Kotzebue, and extends approximately 54 miles from the coast
of the Chukchi Sea to the Red Dog Mine, one of the world’s
largest and richest lead and zinc mines. Based on in-depth
analysis, PND designed a road alignment that maintained close
proximity to borrow sources, minimized the number and size
of stream crossings required, and provided the best available
foundation. Although the majority of the route traverses
frozen soils, which become weak when thawed, the finished
road safely conveys 1,600-ton modules and large ore carriers
year-round. This was accomplished by way of a combination
of gravel and high-strength geotextile fabric.
West Dock Causeway | North Slope, Alaska
PND earned a Silver James F. Lincoln Arc Welding Foundation
Award for its design of the West Dock Causeway breach bridge
on Alaska’s North Slope. The structure is a single-lane, torsionally
resistant steel box-girder bridge with a 700-foot-long, four-span
main bridge and 80-foot-long, single-span approach trestles at
each end, for an overall length of 900 feet. The vertical piers are
supported by eight 36-inch-diameter batter piles designed to
resist ice loads of up to 1,200 kips with 40-foot scour.
CD-4 Road | North Slope, Alaska
PND provided engineering and construction oversight for construction of this 3.8-mile gravel road and 10-acre gravel drill pad
located within the Colville River Delta. This facility lies within the Colville River Unit on the North Slope of Alaska and is located on
permafrost in a large river delta. PND’s design efforts included optimizing the road route with analysis of aerial photography and field
investigations in order to minimize exposure to the annual spring floods and impacts to the surrounding tundra habitat. In addition
to the facility’s operational requirements, the project’s design considerations include thermal protection of the permafrost, integration
and protection of the facility within a complex floodplain, and coordination with federal, state, and local permitting efforts.
OIL & GAS DEVELOPMENT
ARCTIC BRIDGE & CIVIL DESIGN
Endicott Causeway | Prudhoe Bay, Alaska
With an overall length of 700 feet, this causeway bridge, over a breach in a
previously earth-filled ocean causeway, is supported by two in-water conical
pile-supported piers and features abutments protected by OPEN CELL SHEET
PILE® bulkheads. The breach is designed for up to 38-foot scour below existing
seabed, and the design ice load on the piers is 500 kips. This project won a
Third-Place Bronze Award in the James F. Lincoln Arc Welding Foundation
Professional Awards Program, as well as an Award of Merit in the American
Institute of Steel Construction Competition for Special Purpose Bridges.
Kuparuk River Module Crossing | North Slope, Alaska
Engineered to accommodate module and carrier load
combinations in the range of 2,300 tons and to resist forces
generated by ice floes up to 5.5 feet thick, this North Slope steel
box-girder bridge exhibits one of the heaviest load capacities in the
world for its construction type. Careful design minimized bridge
length, with a 1,500-foot-long paved low water roadway section
designed to withstand overflow during flood events without
damage. The bridge utilizes OPEN CELL SHEET PILE bulkhead
abutments and won First Place in Alaska Construction & Oil
magazine’s “Heavy Construction Project of the Year” contest, and
a Bronze Award from the Lincoln Arc Welding Foundation.
PND | Arctic Engineering
Kuparuk River Low Water Crossings |
North Slope, Alaska
PND designed these innovative submersible bridges with
combined paved low water crossings on the North Slope of
Alaska. This design saved the owner approximately 50 percent
($10 million) over the cost of elevated bridges for the crossing
of two river channels in a flood plain nearly two miles wide.
Extreme environmental conditions, design vehicle weights
approaching 4 million pounds, impact loading from river ice 5
feet thick, and discontinuous permafrost soil conditions posed
interesting and unusual design and construction challenges.
The strength, resilience, and construction flexibility of welded
steel were fundamental in providing the most cost-effective
solution for this project. The project won the following: James
F. Lincoln Arc Welding Award, AISC/NSBA Bridge Special
Award, and the Deep Foundations Institute Special
Recognition Award.
Gas Cycling Project Infrastructure Development | North Slope, Alaska
PND was responsible for all of the civil work associated with developing this multi-billion dollar project’s transportation and
infrastructure systems consisting of water access; module off-load marine facilities; a service pier; bridges; gravel and ice roads and
pads; hydrology; upland and bathymetric surveys; met-ocean investigations and associated coastal engineering; airstrip and associated
facilities, including instrument landing systems; all containment, including tank truck and fuel tank farms; water supply; and material
sources. The project is located on Alaska’s North Slope near the Arctic National Wildlife Refuge (ANWR) and is underlain by
permafrost 2,000 feet deep throughout the project site.
© JUDY PATRICK
Liberty Island Offshore Development | North Slope, Alaska
PND led the civil team for this North Slope development, which evaluated geotechnical data; identified material sources; utilized
aerial photography for road and bridge layout; conducted hydrology and hydrological studies, met-ocean studies, and sea ice
encroachment studies; developed design ice criteria; engineered road and pipeline bridge designs; and assisted in environmental
and cultural/archaeological studies for various project development alternatives.
The alternative selected for construction involved an expansion of an existing offshore drilling pad utilizing 2,000 feet of OPEN
CELL SHEET PILE shore protection in up to 10 feet of water and the replacement of an existing bridge’s superstructure. The
island expansion and barge dock were designed for very heavy oilfield drill rig loads and self-propelled module carrier loads to
support the planned ultra-extended-reach drill rig equipment (longest in the world, and largest). PND also designed the conductor
piles and well cellar lids that were specialized for the very high loads and particular needs of this development. PND provided
construction inspection, QA and management of the construction of the island expansion, gravel material source development,
and existing bridge demolition and replacement.
RESEARCH & DEVELOPMENT
OIL & GAS DEVELOPMENT
Pile Testing In Permafrost Soil
PND performed long-term pile creep tests in Alaska’s Arctic region. Twelve piles were tested in gravelly and silty permafrost
soils. These tests characterized the adfreeze bond developed by a new pile installation process that is considerably more
economical than traditional Arctic pile installation procedures. The testing system applied pile loads of more than 800,000
pounds and was designed for remote use to function autonomously, keeping a constant load without manpower for maintenance.
Northstar Offshore Island | Prudhoe Bay, Alaska
PND provided design services for the Northstar oil drilling and production island in the Beaufort Sea over two phases. The first phase
consisted of a 320-foot by 140-foot OPEN CELL SHEET PILE dock with fenders, foundations, and various structural elements at
the south end of the island. The dock was built in two separate halves with a central trench section to allow the installation of
pipelines onto the island. The pipeline transition trench was later closed by a sheet pile closure wall, resulting in a solid dock face.
Other aspects included heliport design; foundation design for the processor, compressor, turbine and fuel tank buildings; budgetary,
administrative, project management and alliance support; and design services for temporary island access during the first year of a
two-year construction program.
During the second phase of the project, PND developed, reviewed, and tested new shore protection alternatives for the island,
including an OPEN CELL SHEET PILE perimeter wall and rock berm alternatives. The PND effort included extensive and
simultaneous physical and numerical modeling to test and refine concept alternatives and ensure accuracy. The work included physical
modeling in wave tanks at Oregon State University and Texas A&M University, as well as physical modeling of ice effects in tanks in
Newfoundland and Finland. Computer modeling included ice simulations, CGWAVE and COBRAS wave modeling, and structural
finite element modeling.
Additionally, as part of an enhancement project, PND designed an enlarged sheet pile-protected area for a new operations
center/living quarters, a high-capacity module barge dock designed for 4,300-ton module offload, seawater intake and sump, offshore
dredging, and an ARKTOS emergency vehicle egress ramp. The scope included concept through final design, permitting, assistance,
physical/numerical modeling of wave/ice interaction, cost estimating, constructability reviews, construction inspection/QA, and
project management.
PND | Arctic Engineering
Wave Tank and Ice Tank Physical Models
Ice Beam and Borehole Jack Testing
PND performed a study of mechanical ice strength properties in
the Colville River. A series of tests, including ice beam bending
tests and confined compressive strength measurements using a
calibrated borehole jack, were conducted to establish the bending
and compressive strength as well as mechanical characteristics of
the ice for design purposes. The test procedures involved jacking a
series of cantilevered beams of ice and pulling upward on the ice
beam to break the ice in a way similar to the expected mode of
failure for design use. The test results were in the anticipated range
and served to validate the design.
Model testing using both numerical (computer) and physical
models are often done for Arctic and ocean structures. PND
has tested designs for Beaufort Sea artificial islands in both 3-D
ice tanks and large wave basins. For one particular project,
slope protection improvements for an existing petroleum
development Arctic island were developed by PND. Both
sloping armor rock and vertical wall steel bulkhead designs
were tested. The island is approximately 1,400 feet across on
the diagonal, in about 40 feet water depth, and was modeled in
ice tank facilities in Finland and Newfoundland. Wave tank
testing was conducted at facilities at Oregon State University
and at Texas A&M University. The physical models helped
answer key questions about the risk of both ice and wave
overtopping, ice behavior, wave deflector design, and the
stability of the armor rock slope protection.
P N D
ARCTIC STRUCTURES DESIGN
E N G I N E E R S , I NC.
PND’s Alaskan roots have enabled the firm to be at the forefront of
Arctic engineering. Working in the world’s Arctic regions requires
more than traditional engineering skills. Special obstacles created by
the climactic, geological, and logistical conditions of the Arctic and
subarctic require knowledge and techniques that are rarely
encountered in conventional engineering. PND’s vast Arctic
experience enables us to deal with the challenges of design,
construction, and operations in Arctic regions of the world.
Our expertise in this field covers many aspects of engineering, ranging
from building and bridge design to site civil and geotechnical design. It
includes the design of Arctic marine facilities and offshore drilling
islands. It also involves Arctic hydrology studies and permafrost
foundation design, as well as ice-structure interaction. We routinely
design for severe environmental conditions, including heavy snow
loads, both continuous and discontinuous permafrost, ice interaction
loads, and extreme temperatures. PND’s broad Arctic experience has
emphasized the importance of dealing with a host of critical issues
such as cold-temperature material toughness; the effects of spring
break-up on rivers for both flooding and bridge design; remote access
utilizing ice roads and pads; and construction logistics associated with
the Arctic.
PND has successfully completed projects in the Arctic and subarctic
areas of Alaska, Canada, and northern Russia. Schedules and quality
have been tightly maintained despite extremes in weather and
logistical conditions. Our Arctic experience is underscored by a
“can-do” attitude regardless of any technical, extreme
environmental, or logistical problems. Since the founding of the
company, PND has provided professional services tailored to the
needs and schedules of its clients, utilizing state-of-the-art
technology and skills. Many of our Arctic projects have won
prestigious awards for their innovative design and construction,
including the West Dock Causeway and Endicott Causeway breaches;
Kuparuk River Bridge and Low Water Crossing; the Oliktok Point
Dock; and pile foundations in permafrost for the Napaaqtugmuit
School in Noatak, Alaska.
Drill Rig 6 | North Slope, Alaska
Kuparuk Pipe Restraint Tower | North Slope, Alaska
PND designed this award-winning, four-story restraint tower
built to stabilize an oilfield separator by devising a remarkably
stiff, axially-loaded structure where deflection from bending
stress is virtually eliminated. Using high-grade, 48-inchdiameter surplus pipeline pipe from the Trans-Alaska Pipeline, a
48-foot-tall, two-legged, welded pipe structure was developed
that would transmit loads axially to a frozen foundation.
Dubbed a bi-pod, the structure utilized a massive prefabricated
steel weldment as a cap to which the crude oil piping system was
anchored. This innovation earned a Lincoln Arc Welding
Bronze Award.
PND designed all structural framing for a new drill rig on the
North Slope of Alaska, which at the time was reported by the tire
manufacturer to be the largest rubber tire vehicle in the world. At
more than 3 million pounds, Drill Rig 6 utilizes welded steel
components, including a backbone of twin 6-foot by 10-foot box
girders to form a self-mobilizing unit. This project won a Lincoln
Arc-Welding Award for Best of Program.
The rig is capable of moving at speeds of 2.5 mph in both
longitudinal and transverse directions. This mobility is made
possible by six sets of hydraulic drive bogies, each of which has
twin 11-foot-diameter rubber tires. Each bogie is capable of
supporting a load of 300 to 400 tons.
Napaaqtugmiut School | Noatak, Alaska
PND provided civil and structural engineering design for this single-story, 50,000-square-foot building, including cafeteria, gymnasium,
and two classroom wings for grades K-12. PND designed a pile foundation for the structure in permafrost soils. The building is
elevated above the permafrost to prevent thawing of marginally frozen soils. Significant consideration was given to developing a
lightweight structure, since all materials had to be flown in to the site. The remote location made clarity of design and ease of
construction critical for this project. The structure was built with steel-braced frames designed to resist lateral wind and seismic loads.
PND | Arctic Engineering
PND Engineers, Inc., founded in 1979, is a
full-service consulting engineering firm
that provides civil, marine, geotechnical,
structural, and construction inspection
services for a wide variety of projects. Our
Arctic and cold regions design experience
ranges from the Russian and Canadian
Arctic regions, and throughout Alaska, for
more than 30 years.
P
N
D
E N G I N E E R S , I N C.
Headquarters:
Anchorage Office
Juneau Office
Seattle Office
1506 West 36th Avenue
9360 Glacier Highway, Suite 100
1736 Fourth Avenue S, Suite A
Anchorage, Alaska 99503
Juneau, Alaska 99801
Seattle, Washington 98134
Phone: 907.561.1011
Phone: 907.586.2093
Phone: 206.624.1387
Fax: 907.563.4220
Fax: 907.586.2099
Fax: 206.624.1388
Palmer Office
Houston Office
550 S Alaska St., Suite 207
10497 Town and Country Way, Suite 210
Palmer, Alaska 99645
Houston, Texas 77024
Phone: 907.707.1081
Phone 832.930.4830
PND Engineers Canada, Inc.
Vancouver Office
Suite 2000, Oceanic Plaza
1066 West Hastings Street
Vancouver, BC Canada V6E 3X2
Phone: 604.601.5247
For additional information please visit our website.
www.pndengineers.com
c Copyright 2015, PND Engineers, Inc.
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