TBT Engineering and its staff are well qualified with extensive experience in geotechnical engineering for foundations. Our foundation experience covers a wide range of project types including infrastructure, heavy industrial foundations, commercial structures, bridges, culverts, and highway and railway embankments. Foundation types, stabilization measures and ground improvement techniques include piles, rock anchors, retaining structures, lightweight fills, footings, mat foundations, frost protection measures, dynamic compaction, and lightweight fills.

Geotechnical Engineering Service Listing

A partial list of relevant Project experience for TBT Engineering and/or its staff is as follows:

Island Drive Bridge, Thunder Bay, ON:

Cook Engineering Ltd.

At 234 m, the Island Drive Bridge is the longest integral abutment bridge in Canada. This project involved detailed field investigations (both on and off shore), extensive geotechnical laboratory analyses and advanced geotechnical modeling. Key foundation design issues included:

• assessment of integral abutment pile deflections and soil stiffness
• slope stability and consolidation analyses for staged construction for a 10 m high approach embankment over weak clays (assessed for both subexcavation methods and wick drains)
• determination of lateral soil deflections on adjacent hydro tower foundation utilizing finite element modeling
• and constructability assessment for the placement of more than 10 m of fills for three piers to be constructed over soft riverbed sediments

Building Settlement Evaluation, Terry Fox Elementary School, Ottawa, ON:

IRC Batten Sears Group Inc.

Geotechnical engineering assessment of building settlements. Various possibilities of the reported settlements were investigated and included, long term consolidation, ground loss, frost heave, changes in moisture content, and bearing capacity. Two primary causes of settlements were identified for separate sections of the school. Slope instability of a 6 m high creek valley slope was identified as the root cause for settlements along one section of the school, while consolidation from tree roots below the foundations was identified as a source of settlement at another location. Through detailed slope stability analyses of the slope, it was determined that extensive slope re-grading and removal of some port-a-pack classroom additions would be the most feasible remediation option.

Impacts on Trunk Sewer from Proposed Commercial Development, Thunder Bay, ON:

OPUS

The proposed commercial development involved a significant raise in grade and the construction of several commercial buildings adjacent an existing trunk sewer buried at a depth of approximately 10 m. Given the compressible nature of the clay soils on site and large loads from the proposed construction, stresses and settlement induced onto the sewer were of concern. This assessment determined there was significant risk to the sewer in terms of hydraulic and structural integrity. Alternate foundation types and various modifications to site grading (including lightweight fills) were developed to mitigate these risks.

Highway Embankment Failure, Hwy 11 South of Polly Lake Road:

Ministry of Transportation

Geotechnical investigation for stabilization recommendations for an embankment failure which occurred on the west side of Highway 11, approximately 100 m south of Polly Lake Road. The failed embankment (approximately 8 m high) partially filled in an existing creek located near the toe of the embankment. Scope of work for this project was to assess slope stability and provide comparative costs for various remedial options. Key geotechnical tasks and issues included:

• back analyses of existing conditions
• design of various slope stabilization measures including:
  • mechanically stabilized earth (geogrid),
  • lightweight fills (foam insulation),
  • construction of a toe berm, and
  • excavation and replacement of failed materials

Moosonee Water and Wastewater Design Build Project, Moosonee, ON:

Reid Crowther and Partners

Geotechnical investigation and design recommendations for the construction of a water treatment plant with associated reservoir, a low raw water pump system, sewage lagoon, sewage pumping stations, forcemain and watermains. Key geotechnical tasks and issues included:

• design of containment berms for 18 ha sewage lagoon utilizing cut and fills operations in native silts. covering an area of 18 ha
• piled foundation design for water treatment plant
• riverbank slope stability improvement design for water intake structure

Bridge Approach Grading, Eleanor Bay and Big Grassy River Bridges, Morson, ON:

McCormick Rankin Corporation

Geotechnical investigations for bridge approach grading for two bridges. The existing approaches were to be raised by 1 to 2 m. The approaches were situated over existing causeways, which were underlain by soft clays. To facilitate construction of the grade raise while maintaining embankment stability and improving settlement performance various geotechnical treatments were designed and evaluated. Extensive consolidation and strength testing of the foundation soils were required for detailed design. Key geotechnical tasks and issues included:

• back analyses of existing conditions
• assessment of various stabilization and settlement improvement options including:
  • construction of flanking berms
  • lightweight slag fills
  • Elastizell foam concrete, and/or foam insulation

Construction Impacts on Segmental Sewer, Famous Players Theatre, Thunder Bay, ON:

Tom Jones Corporation Inc.

Geotechnical assessment and recommendations for a piled foundation, grade raise and impacts of construction on a near by buried segmental sanitary trunk sewer. Project involved the prediction of construction effects (including piling operations) on the adjacent sewer. Later, a series of test piles were driven to confirm pile capacity and to optimize the design with respect to potential construction effects on the sewer. During driving a test piles an extensive monitoring program was implemented to measure vibrations, ground movements, sewer deflections, and porewater pressure generation in the surrounding soils. In addition, visual inspections of the sewer were carried out. Based on the results of the monitoring program, it was determined that the planned piling operations would not pose any significant risk to the sewer.

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