City of Winnipeg SOUTHWESTERN RAPID TRANSIT CORRIDOR Bidder Meeting October 16 th, 2009

Site Location

Field Investigations - Klohn Krippen (2003) - Geotechnical 4 deep test holes, 1 shallow Groundwater monitoring Laboratory testing –AECOM (2009) - Geotechnical 2 deep test holes ( rock coring) Groundwater monitoring Laboratory testing –AECOM (2009) – Hydrogeological Two test wells drilling Field pump tests

Location of Test Holes TW 2 TW 1

Soil Stratigraphy

Field and Lab Results

Groundwater Conditions –Clay : 2 m below ground, Elv. 231 m –Bedrock/Till : Elv. 224 to 226 m –Impact on: Excavation stability Global stability Seepage

Geotechnical Concerns – Foundation type – Rebound, heave and settlement – Retaining walls – Base heave – Temporary shoring and excavation plan

Bearing capacity and foundation type – Raft foundation – Design based on the concept of floating foundation – Bearing capacity and settlement pressure are defined

Rebound, Heave and Settlement

Retaining walls - Reinforced Concrete U-shaped section - Reinforced Concrete Cantilever wall - Coulomb Theory - Design for surcharge from compaction during construction - Design for live load surcharge from Cooper E90 loading -

Clay Till/Bedrock FS = W clay / γ w h Base heave h W clay

TYPICAL EXTREME HISTORICAL

Temporary shoring and Excavation plan – Cut and cover construction – Staged construction, Stage I and II – Site constrains: Limited space Utilities Private property Proximity to CN tracks – Excavations plan include: Open excavation Cantilever / Braced Shoring Combination of shoring and open excavation

Temporary shoring and Excavation plan – Excavation configurations Open Excavation, up to 6 m cut Other geometry < 6m cut

Temporary shoring and Excavation plan – Excavation configurations Braced Shoring up to 9.5 m ~ Min ~ 5

Temporary shoring and Excavation plan – Excavation configurations Combination of Braced Shoring and Open excavation m bench 5 m Crane pad varies 5 m Min. varies 7 Max.

Temporary shoring and Excavation plan Lateral Loads from Surcharge

Temporary shoring and Excavation plan Base Instability : analogous to bearing capacity

Global Stability - Stress – stability coupled finite element analysis - Locally acceptable soil parameters - Account for excavation unloading - Model train loading - Design objective FS = 1.30

Stability output

Stress-Deformation Analysis

Performance Monitoring Program Instrumentation will be installed to monitor – Displacement of railway tracks – Displacement of shoring system – Horizontal subsoil displacement – Excavation heave – Groundwater levels

THANK YOU