Project Summaries

Project

CN/GO Mainline Expansion

Location

Port Credit, Ontario

System

Geopier GP3®

Challenge

The expansion of the Lakeshore GO railway line required a large geogrid reinforced retaining wall to act as a grade separation structure. This was to be placed adjacent to an existing river and a perpendicular storm channel. Embankment fill created significant global stability issues for the retaining wall as well as heavy passing rail loads.

Solution

The Geopier GP3 system provided global stability improvements through the introduction of a zone of improved shear strength.

The Geopier system was installed in an especially tight corridor between the existing rail embankment and storm channel. This system effectively supported the five-metre-high retaining wall through challenging fill soils, effectively solving the global stability challenges for this important rail corridor.

“GeoSolv is very innovative and accommodating. Their expertise in the field helped to expedite a very time-sensitive project with excellent results”

Jim Whitehead — Grascan Construction

Project

Conestoga College

Location

Kitchener, Ontario

System

Geopier GP3®

Challenge

A new three-storey wing was to be added to the existing campus building to support the increased growth of this education centre. Problem peat and fill soil was encountered on a portion of the building’s footprint, with the other half of the building’s footprint underlain by higher quality compact native sand and gravel. Excavating and replacing the peat and fill soils would have created significant challenges and excessive additional cost due to the need for additional shored excavations to support the adjacent structures.

Solution

The Geopier GP3 system that was implemented quickly and effectively to support the problem-half of the building. As a result, it significantly improved the rigidity the peat and fill soils, and matched the bearing capacities of the footings in the other stable half of the building.

Project

Foodland & L.C.B.O.

Location

Thornbury, Ontario

System

Geopier GP3®

Challenge

Construction of a Foodland Supermarket and an LCBO outlet was planned on a greenfield site near Lake Huron that contained a sandy, fill, and peat-laden soil, which had a natural bearing capacity of 50 kPa SLS and 75 kPa ULS. This was considered unsuitable for the construction and overall stability of these two commercial structures. Through a GeoSolv consultation, it was determined that the Geopier GP3 system could provide 150 kPa SLS and 225 kPa ULS bearing capacity and provide uplift control where necessary.

The Geopier GP3 system was installed quickly and efficiently, with over 35 elements being installed per day. Threadbar harnesses were added to Geopier elements to provide uplift capacity without detriment to the compressive capacity of those elements. The Geopier system provided a floating foundation on an engineered crust of soil where one was not present naturally, thereby reducing the project cost as compared to a deep foundation.

Winter construction and rapid installation improved the overall construction project schedule and created significant cost efficiencies.

Project

Mountain Locks Plaza

Location

St. Catharines, Ontario

System

GP3®

Challenge

Construction of four large commercial structures, including a Sobeys, LCBO and two other buildings encountered clay, silt and fill problem soils that would typically require excessive excavation, replacement or deep foundations. Up to 500 kN column loads and up to 12 kPa slab loads could not be supported on spread footings on the existing soils.

The Geopier system provided high-bearing capacity at high elevation within soils that would otherwise have been deemed unsuitable and would have required costly removal. By utilizing the Geopier system, excavation was avoided and no dewatering was required.

During construction, a previous building foundation (obstruction) encountered below the fill was able to be left in place at 8m below grade, given that the Geopier system does not require end bearing to support load.
The Geopier system provided significant cost and schedule control, saving substantial quantities of excavated fills that would have been challenging and expensive to dispose of.

Project

Oxley Wind Farm

Location

Harrow, Ontario

System

Geopier Armorpact®

Challenge

A wind farm consisting of 100m tall wind turbines founded on 19.2 m diameter spread footings and involving loose sand and organic problem soils. In addition, high ground water prevented the use of standard spread footings.

Solution

GeoSolv determined that the Armorpact system was the most cost-effective alternative to support the proposed tower in place of deep foundations. The system would provide up to 275 kPa ULS and 180 kPa at SLS,  as well as limited overall tilt of the wind turbine to less than 0.17 degrees. The system allowed the turbines to be supported on the same spread footings design as those constructed on good quality ground.

The Geopier Armorpact system provided for cost-effective, high-bearing capacity spread footings. This system improved the project schedule and eliminated the need for deep foundations, which would not have been financially feasable.

“GeoSolv simplified the construction process for these towers,” – Jason Van Geel, Carlsun Energy

Project

Wal-Mart Store Addition

Location

Orangeville, Ontario

System

Geopier Impact® and Micropiles

Challenge

Construction of Wal-Mart’s 3,000 m2 addition to the existing Orangeville location encountered problem soils that created concerns for this large construction project. Excavation and replacement of the problem peat soils would have had the potential to undercut the existing structure and create unpredictable additional costs and significant delays.

Solution

GeoSolv provided a sound settlement control solution utilizing Geopier for spread footings at 240 kPa SLS for a thin, unreinforced slab. Since a displacement technique was used, the collapsing soil and high ground water levels were not an issue. Impact elements were installed through the fill and organics quickly, efficiently, and without spoils. Continuously cased drilled micropiles were used as underpinnings to increase capacity for existing footings.

The use of impact elements prevented excavation of existing fill as deep as 6.6m, preventing the under-cutting that would have occurred with excavation and replacement. This solution also prevented the need for large-grade beams and the structural slab that would have been required with expensive deep foundations. This system allowed for simplicity of construction through slab on grade and spread footings elements.