U of S Graduate Student Presentations

Please join us on Wednesday October 2 for teh annual U of S graduate student presentations.

A buffet lunch will be served at 11.45 am in the South Dining Room at the Park Town Hotel - access through the restaurant with the presentations commencing at noon. Please provide your vehicle license plate to reception to take advantage of free parking in the hotel parking lot.

NEVIN CROSS - A COMPARISON OF IL AND CRS CONSOLIDATION TESTING AND EVALUATION OF THE NON-LINEAR SOIL BEHAVIOUR OF A CLAY TIL IN SOUTHERN MANITOBA

A large earthen embankment has been constructed in Brandon, MB to support two new bridge structures. The site stratigraphy consists of an upper complex unit of soil fill, clays, and sands, which is underlain by five clay till units and shale bedrock. Seismic cone penetration testing and pressuremeter testing were completed as part of the initial embankment design, and conventional incremental loading and constant rate of strain (CRS) oedometers were completed at the University of Saskatchewan. This paper compares the compressibility characteristics and coefficient of consolidation estimated from CRS and IL tests completed on the clay till unit located 11.6 mbgs to 21.5 mbgs. Interpretation of the ground response during in-situ testing, and specimen response during laboratory testing have been used to develop a stiffness degradation curve to describe the non-linear soil behaviour of the clay till unit.

AKASH MUNDI - SUCTION BEHAVIOUR OF POLYMER-BASED NON-WOVEN GEOTEXTILES: DEVELOPING TESTING METHODS AND IDENTFYING INFLUENCES u

As of 2024, both the water retention behaviour of non-woven geotextiles, and the factors that influence it, remain largely unexplored in a geotechnical context. Using a novel direct-suction measurement method alongside an adapted ASTM D6836-16 method for measuring the soil-water characteristic curve of soils, we can estimate the water characteristic curves of various geotextiles. The newly developed testing method measures the suction and water content of the sample directly, not requiring inference from mass measurements as is required in the current ASTM procedures. This research observes the influence that intrinsic material properties have on nylon, polyester, and polypropylene fibers' water retention under varying applied suction. Analysis of the generated curves showed that the sample fibers' contact angles, fiber diameters, and porosity had a major influence on the sample's suction behaviour. These findings may help engineers inform their selection of non-woven geotextiles for projects, and help manufacturers design non-woven geotextiles for specific applications.

IAN ADAMS - A SITE CHARACTERIZATION AND SHEAR STRENGTH TESTING OF A LANDSLIDE IN THE ASSINIBOINE RIVER VALLEY

The Canadian National Railway (CN) and the Canadian Pacific Railway (CP) cross the Assiniboine River nine times within Saskatchewan and Manitoba. The Assiniboine River Valley has many slow-moving landslides, posing challenges for railway operations. The presented study site is at CN’s Rivers Subdivision, near Miniota, Manitoba. Site stratigraphy consists of glacial till, over weathered clay-shale, over intact clay-shale. Two failure zones have been identified (1) a shallow slide immediately upslope of the railway (2) a deep-seated slide downslope of the alignment, demonstrating an apparent toe near the valley floor. Continuous core specimens of the marine clay-shale have been recovered for characterization. The stiff, heavily overconsolidated, plastic soil includes beds of weakness associated with bentonitic seams and previously sheared zones. Characterization and shear strength testing have been completed on intact unweathered clay-shale specimens.