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Dimension® Foundation Improvement System

Reliable foundation construction over poor soils is one of the most difficult challenges that developers and designers face. The potential for differential settlement can threaten a project’s success. In addition, poor soil conditions can substantially increase project costs and construction time. 

Conventional solutions including overexcavation, additional concrete and deep foundations have proved to be expensive, labor intensive and sometimes environmentally unsound. By contrast, Tensar’s Dimension® Foundation Improvement System provides an economical alternative to a potentially costly problem. The system has saved developers as much as $1 million on individual projects.

The Dimension System was developed to construct reliable foundations at a lower cost than conventional foundation improvement methods. It is a Mechanically Stabilized Earth (MSE) System composed of cohesionless soil and Tensar® TriAx® Geogrids; components interlock to create a stiff platform over weak, compressible soils. The Dimension System’s composite structure distributes loads widely and uniformly over underlying soils.

Compared to unimproved foundations, the Dimension System can:

  • Increase the effective bearing capacity by a factor up to three
  • Reduce estimated settlement up to 60%
  • Mitigate differential settlement
  • Improve the margin of safety for unforeseen soil conditions

Load Transfer Platforms (LTPS)

Optimizing Deep Foundation Designs

The Dimension LTP System is a stiff, geogrid-stabilized composite structure designed to transfer loads to stiff columns in deep foundations. It can be successfully used with several deep foundation systems, and provides an economical solution to design problems associated with settlement-sensitive structures that impose heavy loads over weak soils.

This mechanically stabilized system uses Tensar TriAx Geogrids with compacted granular fill to create a stiffened platform. The platform reduces deflection between the columns that can otherwise be reflected to the surface. Designs can be based on traditional methods for spanning or on an enhanced arching methodology.

By incorporating TriAx Geogrids, the Dimension LTP System:

  • Reduces differential settlement and movement
  • Uniformly distributes earth pressures
  • Eliminates overexcavation and replacement
  • Accelerates construction of embankments

The Dimension LTP System has been proven to:

  • Efficiently transfer loads to rigid column elements
  • Resist lateral thrust at the sides of an embankment
  • Form a stiff foundation that reduces the vertical stress applied directly to weak soil between piles

Load Transfer with Intermediate Foundation Systems

The Dimension System can be used with Geopier Foundation Company’s Rammed Aggregate Pier (RAP) System* to help transfer loads efficiently. In this application, the Dimension System provides a stiffened composite structure that helps distribute loads onto the piers and significantly reduce vertical displacement between them.

*RAP Systems are a proven soil improvement technology that offer an economical alternative to traditional foundation support methods. They often provide a faster and less expensive solution for supporting a variety of settlement-sensitive structures. For more information, visit


TriAx® geogrid and the use thereof are protected by U.S. Patent No. 7,001,112

Firm Foundations for Buildings and Retaining Walls

The Dimension System’s composite structure distributes loads widely and uniformly over underlying soils. 

As an alternative to overexcavation, concrete slabs, cement grouting and deep foundations, the Dimension System:

  • Increases the effective bearing capacity of soils beneath shallow spread footings
  • Mitigates total and differential settlement by forming a stiffened structure beneath concrete footings
  • Reduces undercutting and backfilling
  • Improves the margin of safety against unforeseen soil conditions
  • Provides a Load Transfer Platform (LTP) System when used with deep foundation systems or intermediate foundation systems such as Geopier® Rammed Aggregate Piers®

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