Two parallel tunnels were built in 1976 as part of the first phase of the Edmonton Rapid Transit System. The tunnels, approximately 250 m long, 6 m in diameter, and having centres 11 m apart have been driven in downtown Edmonton with an average of 7.5 m overburden above the crown. The tunnels were located entirely within a dense, jointed till sequence of Wisconsin age.The tunnels were advanced using a mole followed by two systems of soil support. The temporary supporting system consisted of steel ribs and timber lagging while the permanent lining was cast-in-place reinforced concrete. To reduce drag friction, the cutting profile of the mole is about 20 mm larger than the diameter of the shield. The steel ribs are expanded into place by hydraulic jacks.Two finite element analyses were performed. One predicted surface settlements and the other predicted lining stresses. The settlements predicted for a single tunnel agreed closely with observed values but the observed amount was considerably more than predicted for both tunnels. The reasons for this are suggested as being due to a cross tunnel connecting the two main tunnels and to a decrease in stiffness of the soil mass brought about by the moling of the first tunnel.insituassessment of stresses in the ribs was not successful due largely to the fact that the ribs were not expanded entirely against the soil. Thus comparisons with predicted values could not be made and values of the earth pressure at rest could not be established. However, rib deformations were essentially complete within a few days thus confirming the essentially time-independent character of the deformational behavior of the till.