Ground Improvements

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OVERVIEW

Ground Improvements include five main areas: Aggregate Piers, Vibro Compaction, Cutoff Walls, Grouting and Soil Mixing. All five of these sections are outlined below along with links to some of our work. If you are looking for more information, be sure to visit our Contact Page to request more information.

Aggregate Piers

Aggregate Piers (also called stone columns or aggregate columns) are a ground improvement method that uses compacted aggregate to create stiff pier elements. Aggregate Piers help increase bearing capacity, shear strength, rate of consolidation, liquefaction resistance, and reduces settlement. Typically they are used in sands and unstable soils.

ADVANTAGES

Rapid Installation
Cost Effective compared to other foundation options
Creates additional drainage paths
Allows for high level of compaction
Efficient QA/QC procedures

Vibro Compaction

Vibro Compaction is a ground improvement method that densifies deep cohesionless soils to increase bearing capacity, increase shear strength, reduce settlement, and increase liquefaction resistance. This technique is typically used in cohesionless soils. Applicable soils include clean sands with less than 15% silts and/or less than 2% clay.

ADVANTAGES

Cost effective compared to other foundation options
Effective Above and Below the water table
Faster than other foundation options
Can increase angle of internal friction by 5-10 degrees

Slurry Trench Cutoff Walls

A Slurry Trench Cutoff Wall is a technique used to restrict horizontal movements of liquids. Construction involves digging the wall under a bentonite or polymer slurry with a long stick excavator or clamshell and replacing the removed material with a low permeability material. The low permeability material is often a mix of cement, bentonite, and soil. This technique is used to control ground water seepage into an excavated area for temporary or permanent applications. The technique is also used frequently to prevent seepage in dams.

ADVANTAGES

Efficient QA/QC Procedures.
Easy to check depth and confirm that excavated materials are in desired stratum
No joints between panels or construction segments

Grouting

There are many types of grouts and grouting techniques used for a variety of applications. We have experience in chemical, permeation, pressure, and curtain grouting. Please contact us to discuss what options work best with your Project’s needs.

ADVANTAGES

Can work in tight working conditions and low overhead environments
Computer monitoring of grouting shows real-time analysis of construction process
Can be used in most soil types
Can be installed under existing structures

Soil Mixing

Soil Mixing (Also called mass stabilization) is a technology to stabilize and strengthen soils at shallow to moderate depths using a binder material. Mass mixing methods can be used to treat soft clays, peats, sludges, and dredged material. Typical uses for this technique include roadway and railway embankment, and support of structures.

ADVANTAGES

Can be used to stabilize peat and other soft soils, and to treat contaminated soils
Can stabilize large blocks of soil
Quicker and less expensive that many other alternatives (such as mass replacement)
Lower environmental impact than other solutions
Traditional binders of common materials – Portland cement, lime, slag, flyash

Ground Improvement Projects

Hebron Aggregate Piers

St. John's, NL

Scope: 9,513 VF of Aggregate Pier Installation. Depths up to 70 ft. Piers installed along man made bund wall to improve fill material to allow the construction of a cement-bentonite cutoff wall.

Hebron Slurry Trench Cutoff Wall

St. John's, NL

Scope: 61,330 SF (97 panels) and 800mm wide of cement-bentonite cutoff wall installed along a manmade bund wall to prevent water inflow during the construction of the Hebron GBS, an off shore oil platform.

Midtown Tunnel Vibro Compaction

New York, N.Y.

Scope: 14,808 VF Land based vibro compaction and 6,388 VF of Marine based vibro compaction. Vibrocompaction required on this project to compact engineered fill that replaced dredged unsuitable soils for a new tunnel.

Cannelton Vibro Compaction

Cannelton, Ind.

Scope: 19,831 VF and 866 EA compaction columns installed along a manmade bund wall to improve fill material to allow the construction of a cement-bentonite cutoff wall.