Lecture :

• 5:30 PM: Cocktails and Socializing

• 6:30 PM: Dinner

• 7:30 PM - 8:30 PM: Main Lecture

Presentation Title: Influence of Exsolved Gases on Slope Performance at the Sarnia Approach to the St. Clair River Tunnel

In 1993, over 100 years after completion of the original St. Clair Tunnel and its approach cuts, work commenced on the new St. Clair Tunnel. The new tunnel alignment used the existing approaches, but the larger tunnel required additional excavation to widen and deepen the original cuts. In Sarnia, Ontario, the new construction triggered unusual, deep-seated deformations on the south slope of the approach. Limit equilibrium analysis using undrained shear strengths evaluated from CPT can predict low FoS values consistent with the observed movements; however, the reason for the lower than expected shear strengths within portions of the clayey stratum was unclear. Finite element analysis was used to model the 1993 construction, but initial…