The unexpected performance of a silt impedes a trenchless installation
Tony Sangiuliano, Jim Robinson, Ailsa Craig, Phillip (Phil) Bedell
In the proceedings of: GeoNiagara 2021: 74th Canadian Geotechnical Conference; 14th joint with IAH-CNCABSTRACT: An understanding of the subsurface and groundwater conditions is essential in the selection of a tunneling methodology. On a recent Ministry of Transportation of Ontario (MTO) project, the tunneling contractor selected a steered auger bore technology for the installation of a 155 m long, 1219 mm diameter steel casing for watermain to be installed beneath the Hwy 401/Leslie St. Interchange. This selection was based on the anticipated subsurface conditions as described in a Foundation Investigation Report (FIR) included in the Contract Documents. However, differing soil conditions comprised of highly dilatant silts were encountered from the entry to within 30 m of the exit portal. The dilatant silts contributed to difficulties in advancing the casing forcing the Contractor to adjust in order to complete the installation.
RÉSUMÉ: Une compréhension des conditions du sol et eaux souterraines est essentielle pour la sélection d’une méthodologie de tunnel. Dans le cadre d’un projet récent du Ministère des Transports Ontario (MTO), l’entrepreneur de tunnels a choisi une technologie de forage de tarière guidé pour l’installation d’un boîtier en acier (casing) de 155 m de longueur et 1,219 mm de diamètre pour une conduite d’eau principale qui sera installé sous l’échangeur de l’autoroute 401/Rue Leslie. Cette sélection était fondée sur les conditions souterraines prévues telles que décrites dans un rapport géotechnique "Foundation Investigation Report (FIR)" inclus dans les documents contractuels. Néanmoins, des conditions de sol différentes composées de limons hautement dilatants ont été rencontrées de l’entrée à moins de 30 m du portail de sortie. Les limons dilatants ont contribué aux difficultés de l’avancement du boîtier forçant l’entrepreneur à l’ajuster afin de terminer l’installation.
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Sangiuliano, Tony, Robinson, Jim, Craig, Ailsa, Bedell, Phillip (Phil) (2021) The unexpected performance of a silt impedes a trenchless installation in GEO2021. Ottawa, Ontario: Canadian Geotechnical Society.
@article{Sangiuliano_GEO2021_533,
author = Tony Sangiuliano, Jim Robinson, Ailsa Craig, Phillip (Phil) Bedell,
title = The unexpected performance of a silt impedes a trenchless installation,
year = 2021
}
title = The unexpected performance of a silt impedes a trenchless installation,
year = 2021
}