Settlement Analysis on Glacio-Lacustrine Clays using Observational Method for a New Interchange in Winnipeg, Manitoba

David Kurz, Prokopi Papadimitropoulos, Jeffrey Barrett

In the proceedings of GeoSt. John's 2019: 72nd Canadian Geotechnical Conference

Session: Professional Practice/Case Studies

ABSTRACT: A new interchange located at the north end of Winnipeg, MB, was substantially completed in the fall of 2018 after 3 years of construction. This interchange included seven bridge structures and embankments heights up to 9 m above original elevation. The embankments were constructed on 8 to 15 m of compressible clay. Wick drains were installed in the clay to accelerate settlement and meet the project requirements that 90% and 95% consolidation occurs before placing granular base course and paving, respectively. Instrumentation installed throughout the site included 60 settlement plates, 9 ShapeArrays (SAAs), over 40 piezometers, and over 15 Inclinometers. At times during construction, differing magnitudes of settlement between the settlement plates versus the SAAs lead to difficulty calibrating numerical models. Thus commonly practiced methods to estimate degree of consolidation were employed. These methods included Root Time and Asaoka (1978) methods. An exponential function using regression analysis was fitted to the available settlement data to assist with predicting degrees of consolidation across the site. Porewater pressure dissipation was also reviewed. This paper presents a summary of the data at key locations and a comparison to settlements predicted prior to construction.

RÉSUMÉ: Un nouvel échangeur autoroutier situé à l'extrémité nord de Winnipeg, au Manitoba, a été achevé substantiellement en automne 2018, après trois ans de construction. Cet échange comprenait sept ponts et des remblais avec hauteurs variant jusqu'à 9 m au- à 90% et 95% aient lieu avant la pose de la couche de base granulaire et le pavage, respectivement. Les instruments installés sur le site comprenaient 60 plaques de tassement, 9 ShapeArrays (SAAs), plus de 40 piézomètres, ainsi que plus de 15 inclinomètres. Au cours de la construction, des tassements variables entre les plaques de tassement et les SAA peuvent entraîner des difficultés à calibrer les modèles numériques. Par conséquent, des méthodes couramment utilisées pour estimer le degré de consolidation ont été utilisées. Ces pratiques incluent les méthodes Root Time et Asaoka (1978). Une fonction exponentielle utilisant une analyse de régression a été ajustée aux données de règlement disponibles pour aider à prévoir les degrés de consolidation sur le site. La dissipation de la pression interstitielle a également été examinée. Ce document présente un résumé des données aux emplacements clés et une comparaison avec les tassements prévus avant le début de la construction.

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Cite this article:
David Kurz; Prokopi Papadimitropoulos; Jeffrey Barrett (2019) Settlement Analysis on Glacio-Lacustrine Clays using Observational Method for a New Interchange in Winnipeg, Manitoba in GEO2019. Ottawa, Ontario: Canadian Geotechnical Society.

@article{Geo2019Paper364,author = David Kurz; Prokopi Papadimitropoulos; Jeffrey Barrett,title = Settlement Analysis on Glacio-Lacustrine Clays using Observational Method for a New Interchange in Winnipeg, Manitoba,year = 2019}