there’s a case where we haven’t achieved that interlock, we
will install supplemental jet grout columns along the secant
pile wall to bridge any gaps.”
Locations where existing subgrade utilities intersect with
the secant pile wall, jet grout columns will be installed to
eliminate the need for relocating the existing utilities and
maintain water cut-off.
“Jet grouting is considered the most versatile ground modification
technique in the world, yet it is still fairly new in Canada,”
said Morrisroe. “It’s been used in the U.S. and Europe for many
decades, but since it can be effective across a wide range of soil
types, including silts and clays, more and more owners and
COVER FEATURE
consultants in Canada are beginning to recognize its versatility
in solving a wide range of geotechnical challenges.”
The team will use the double-fluid jet grouting process
whereby high-velocity, high-pressure cementitious grout
erodes and mixes the soil to create a high-strength, lowpermeability
soil-cement matrix.
A pre-production test program was performed on sacrificial
elements to verify design strength, geometric properties
and permeability of the soil-cement matrix. Keller uses a proprietary
data acquisition system during installation as a key
element of the quality control program to monitor and control
the jet grout construction parameters.
The transit line
will have up to
25 stations and
stops and will
link passengers
to 54 bus routes,
greatly improving
Toronto’s public
transportation
system.
PILING CANADA 29