1. In early January, Doublestar Drilling (DSD) was
awarded the supply and installation of the secant
pile wall for the Alberta Boot project being built
by Axiom Builders. This particular secant pile wall
contained 441 piles that had depths up to 10.5m and a
diameter of 880mm. The piling was completed ahead of
schedule at the beginning of March. During the project, DSD
had 3 drill rigs performing the piling portion: the Soilmec
SR-75 and the two Liebherr rigs, the LB28 & LB24. DSD was
the selected contractor due to their proven ability to execute in
difficult soil conditions and meet the highly aggressive schedule.
The anchor scope of work began in early March. DSD’s 2 Davey
Kent 725 drill rigs were used to drill the 79 tieback anchors in a
matter of a few weeks. Due to the proximity of the CPR rail lines,
significant testing and quality control measures were required in order
to approve the excavation and encroachment agreements. A unique design
build solution was able to minimize the number of encroaching anchors,
saving the Owner a significant amount of costs. Together, the piling drill rigs
and the anchor tieback drills created high production rates that steered DSD
into a very successful project overall.
ALBERTA BOOT – CALGARY, AB

2. THE CONCORD – CALGARY, AB
The Concord Tower is located in downtown
Calgary on the shore of the Bow River. Doublestar
Drilling (DSD) was contracted to construct the
temporary shoring for the excavation of the luxury
condo parkade and development. The parkade
construction consisted of 4 levels of parkade, which are
well below the Bow River, adjacent to the project. The 19m
deep secant pile wall was incorporated into the engineered
flood mitigation system, which was a significant marketing
feature of the buildings design to withstand future flood events.
The secant piles are 1m in diameter and interlocked 20cm to
provide decreased permeability of ground water from the Bow
River. The increased overlap between piles was due to the permanent
use of the shoring system for flood and ground water mitigation. DSD
was required to use segmental casing for the entire depth because of the
significant ground water and gravel soil conditions. The piles were installed
by DSD’s Liebherr LB36 and LB28 drill rigs.
As a results of the projects success, DSD became a highly preferred contractor
of GeoPacific Consultants, the geotechnical engineering firm representing the
owner. Based on the challenging soil conditions and proximity to the river, many
industry experts have considered this one of the most successful secant shoring
projects located in the channel area of downtown Calgary.

3. 6TH AND TENTH – CALGARY, AB
Doublestar Drilling (DSD) was awarded
the temporary shoring scope of work for
the 6th and Tenth Tower, in Calgary, AB.
DSD provided a design build shoring solution,
consisting of an anchored secant pile wall. Due to
the small footprint of the project, depth, and timing
of construction, this option was selected over a hybrid
secant, shotcrete and soil nail shoring design. At the
time of award, the project was to be the third deepest
excavation project ever completed in Calgary; being to a
depth of ~ 22.5m below grade with 5 rows of anchors.
The greatest challenge of the project was the small foot print and
the limited access to the site. DSD had to design and work around
a significant amount of underground utilities for the construction
of the shoring, and pushed the standard piling installation tolerances
to new levels. The performance of the shoring wall exceeded all
expectations and experienced less than 20% of the expected deflection
during the monitoring.