November/December 2021 - 115

piling rigs and hammers to meet the
changing needs of its contractor customers.
The new XCMG drilling rigs
allow Junttan to provide equipment and
tooling for both driven and drilled pile
foundations. These rigs are designed for
Kelly drilling, continuous flight auger
(CFA), full displacement piles (FDP),
single column mixing (SCM), cased CFA
(CCFA) and low headroom applications.
The XCMG line of drilling rigs operating
weights range from 45 to 200 tons and
torque values between 29 to 180 kip (130
and 800 kN). All are outfitted with
Cummins engines and will be Tier 4 or
greater to comply with emission
standards in the U.S. Junttan USA has
access to the Cummins InSite software
for troubleshooting and diagnostics.
This allows all engine service to be
performed by Junttan technicians with
no outside support. All new products
will be backed by a one-yr/2,000-hr
warranty and handled directly through
Junttan USA. It will provide service, and
stock a comprehensive inventory of
parts for the XCMG product line in Delaware
and Florida, with XCMG committed
to stocking parts at its locations
in Nevada, Texas and Minnesota.
McMillen Jacobs Associates, a
multidisciplinary engineering and
consul t ing firm special izing in
underground and water resources
XCMG foundation drilling rig
projects, played a significant role in the
recently completed Northgate Link
Extension Light Rail project in Seattle,
Washington. The project aims to increase
light rail ridership, improve
travel time and add transit capacity to
the congested Interstate-5 corridor. To
do so, it connects Sound Transit's
University Link light rail segment to the
Northgate business/retail center and
forms part of a system connecting four
major urban centers to the existing
Central Link (that extends from downtown
Seattle to SeaTac airport). It consists
of 4.3 mi (6.9 km) of double-track
light rail, 3.5 mi (5.6 km) in twin bored
soft-ground tunnels and 0.8 mi (1.3 km)
in retained cut fills and elevated structures.
Precast segments were used for
the tunnels. The project also includes
two underground transit stations
(U District and Roosevelt), one elevated
station (Northgate), a portal structure
and 23 cross passages. Both underground
stations were designed as bottom-up
excavations, and the cross passages are
sequential excavation method structures.
As the prime consultant, McMillen
Jacobs provided project management,
tunnel and underground structure
design, estimating and scheduling,
and geotechnical engineering services.
The project team included more than 30
firms, and was constructed in an area
characterized by dense, urban neighborhoods
and complex subsurface and
groundwater conditions, which required
optimizing the location and
alignment of the underground elements.
Yet it was completed under
budget and ahead of schedule.
Roosevelt Station platform for Northgate Link Extension
DEEP FOUNDATIONS * NOV/DEC 2021 * 115
November/December 2021

Table of Contents for the Digital Edition of November/December 2021
