Geotechnical Engineering

Geotechnical Engineering

EPI is a full-service Geotechnical Engineering firm providing expertise on soils, geology, foundation engineering, related Geotechnical, and Geological engineering.  EPI primarily provides consulting and testing services to clients in Illinois, Indiana, and Wisconsin on a variety of projects including: office/warehouse facilities, mid and high-rise condominiums, town home developments, and single family residences.  The majority of our clients are property owners, institutional lenders, architects, engineering firms, holding companies, developers, public and government agencies, law firms, and construction companies. A geotechnical investigation is intended to aid in building foundation design and pre-development planning. This study is generally required prior to obtaining a building permit for a given construction project.

EPI’s Laboratory Services Include:

  • Atterberg Limits
  • Consolidation
  • Material Gradation
  • Moisture Density Relationship (Proctor Analysis)
  • Organic Content
  • Permeability
  • Soil Classification
  • Soil Density
  • Unconfined Compressive Strength
  • Water Content

EPI’s Field Investigation Services Include:

  • Inclinometer Installation/Monitoring
  • Monitoring/Analysis of Load Tests (Pile/Auger-Cast/Caisson)
  • Piezometer Installation/Monitoring
  • Settlement Plates Installation/Monitoring
  • Soil Test Borings
  • Test pits
  • Undisturbed Soil Sampling

EPI’s Geotechnical Services Include:

  • Subsurface Investigations
  • Design Recommendations & Engineering Resist Dynamic Loading
  • Dewatering & Sub-Drainage Systems
  • Earth Dams, Retention Structures, & Embankments
  • Foundation Engineering
  • Ground Modification Techniques
  • Groundwater, Hydrologic, & Hydrogeologic Studies
  • Investigation of Settlement & Subsidence
  • Pavement Design Parameters

EPI’s Deep Foundation Recommendations:
A deep foundation is required when, due to their magnitude, the building loads have to be transferred to the subsurface layer in order to ensure the safety of the structure. Deep foundations are designed to support the structural loads if the soil condition present on-site do not allow the construction of a typical spread-footing shallow foundation system.  At EPI, we are able to provide our clients with recommendation pertaining to the design and construction of a deep foundation system on a case by case basis. Several of the deep foundation system alternatives commonly used are presented below:

  • Caisson – a caisson is constructed by drilling a shaft, which is usually cased during construction. Noted shaft is extended through the layers of unsuitable soil and is terminated upon an underlying layer of hard cohesive soil. The shaft is then filled with concrete after the rebar cage is lowered into the excavation. Depending on the loading and soil conditions present, the caisson can be designed as either a straight-shaft or a belled unit.
  • Rammed Aggregate Piers (RAP) – the installation process starts by drilling a cavity in the ground that is filled with crushed stone, which is compacted in-place by the dynamic impact of a hammer. The ramming process itself pushes the stone into the walls of the cavity. This process densifies the surrounding soil, and also creates the frictional resistance between the soil and stone fill.
  • Grouted Hollow Bar Micropile –a noted foundation uses continuous drilling and grouting, in order to push the pile down to its required depth. This process is designed to extend the pile past the surficial obstructions and softer soils, down into an underlying layer of suitable soil, to generate sufficient frictional resistance for the support of the structural loads.
  • Driven Pile – a long structural member (steel, timber, or concrete) is driven into the soil by repetitive blows of the hammer. This process is designed to extend the pile past the softer soils, down into an underlying layer of suitable soil, to generate sufficient frictional resistance for the support of the structural loads. The tip of the pile will also generate the end-bearing resistance.
  • Helical Pulldown Micropiles – the installation process involves drilling a helically- shaped bearing plate in the suitable soil, thus transferring the foundation loads past any unsuitable surficial soils.  The structural loads are then resisted by the bearing capacity of the soil in contact with the plate.

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