A 32 ft (10 m) high embankment has been built at Matagami, Quebec, on a varved clay deposit of the glacial lake Barlow–Ojibway. This paper reports on some aspects considered in the design, mainly the cementation and the high plasticity of the clay. The variation of settlements and pore pressure is presented and indicates that, 8 months after construction, the pore pressure dissipation is very small while the measured settlements reach 18 in. (45 cm).Triaxial tests, with various consolidation times, were carried out on specimens cut from undisturbed block samples obtained in the same area, in order to study the effect of consolidation on the shear strength of these cemented clays. Results indicate that the undrained shear strength decreases during consolidation until the degree of consolidation reaches 50%. This phenomenon together with the non-dissipation of pore pressure in the field is attributed to the collapse of the cemented structure when the applied pressure exceeds Pc.Similar behavior reported for two other cases of embankments built on deposits of the same origin, leads to the conclusion that the stage construction method is not suitable for embankment on cemented clays, at least those from the glacial lake Barlow–Ojibway, because no gain in shear strength is recorded over a normal consolidation period.

In 1972 and 1973, a winter road crossing eight rivers was built in the James Bay territory to enable the installation of camps and the mobilization of all equipment, materials and fuel needed for the construction of a permanent road leading to the La Grande River. This paper reports on the bearing capacity theory, design, site selection, construction and testing of the ice bridges spanning the main rivers.

The paper reports on the measurement of an arching effect over a large diameter flexible culvert. An arch shape culvert, 51 ft (15.5m) in span, was erected and covered by a 44 ft (13.4m) high embankment. An extensive instrumentation program was laid out in order to check the mobilization of an arching effect during construction by measuring displacements, earth pressures, and stresses in the steel. The instrumentation data indicated that a large portion of the load due to the weight of the soil above the structure was transferred to the adjacent area.