Engineering Services

Foundations impact the earth based on the size and type of the foundation.  Heavier column loads generally require larger foundations, affecting the soils to a greater depth.  During design, Foundation Design, P.C. utilizes 2-D and 3-D computer modeling to assess the allowable bearing capacity of the soil from a bearing failure and settlement failure standpoint.  When the earth is not capable of supporting the column loads due to poor bearing conditions or excessive settlement projections, we provide recommendations for deep foundation system (driven/drilled piles, drilled shafts, helical piles) and/or soil improvement system (rammed aggregate piers, rigid inclusions, Rapid Impact Compaction, Dynamic Deep Compaction, removal/replacement) and work with your design and construction team to develop the more economical approach for your project:

• Spread Footing Foundations
  • Perform bearing analyses and 2-D and 3-D settlement analysis
  • Allowable Bearing Pressures
  • Settlement Estimates
  • Frost Depths
  • Foundation Drain Recommendations/Details
• Deep Foundations (Piles/Drilled Shafts)
  • Allowable compressive loads
  • Allowable lateral loads
  • Allowable uplift capacities
  • Estimated installation lengths
  • All-Pile and L-Pile software assessments
• Soil improvement system assessment
  • Rammed aggregate piers (Geopiers)
  • Rigid inclusions (controlled modulus columns)
  • Rapid impact compaction
  • Dynamic deep compaction
• Surcharging
  • Develop recommended surcharge weight and timeframe estimates for surcharge placement
  • Develop estimates for the amount of total settlement to develop
  • Assess the need for wick drains to expedite settlement

Solar site assessments require knowledge of the foundation system installation process and how it interacts with the earth.  Our qualified staff has experience on over 200 solar site developments to assist your team.  We are aware that the geotechnical challenges associated with solar installations are different from building projects, due to the low vertical loads and high uplift forces acting on the system.  Typically, lightweight C-channel or I-beam piles are driven as the foundation system; being able to drive the piles to a depth adequate to resist the uplift forces is a critical factor in the site assessment process.  Cobbles, boulders, dense soils, or shallow bedrock can require alternate foundation systems to be utilized.  Ad-freeze forces can be excessive, increasing the uplift loads on driven piles, thereby requiring deeper pile penetrations or other frost-mitigation measures to be employed.  Due to the number of supports required, soil corrosion effects need to be taken into account.  In-place soil resistivity testing aids in assessing the appropriate grounding system for the array.  Soil thermal conductivity values can aid in selecting the proper electric cables reducing the chance of wire burn-out.  Transformer, switchgear, and battery storage pads require frost mitigation measures to prevent excessive heaving from developing.  Our knowledgeable staff can assist your team by addressing these important issues on your next project:

• Foundation Assessment
  • C-Channel, I-beam, Screw Piles, Helical piles, ballasted systems
• Soils parameters for use in assessing allowable lateral loads, uplift capacities, and estimated installation lengths
• Corrosion Assessment
• Frost Depth and Ad-Freeze Values
• Transformer, Switchgear, and Battery Storage Pads
• In-place Soil Resistivity Testing
• Soil Thermal Conductivity Testing
• Gravel Road Design

As part of the design analysis, Foundation Design, P.C. assesses the earth and what grading will be required as part of the site preparation work.  To that end, we evaluate whether the on-site soil is suitable to be used in the mass grading and the impacts that the inclement weather in the late fall, winter, and early spring months may have on the site grading operations.  Where unsuitable materials, shallow bedrock, or extremely dense soils are encountered, we delineate the depth of these potential construction issues for use in cost estimating.  Where required, the rippability of dense soil and/or bedrock can be assessed using seismic refraction analyses.  We outline recommendations to address soft and/or unstable subgrades that are expected and outline when soil retention and or dewatering efforts will be needed as part of the site preparation process:

• Suitability of on-site soil for reuse in mass grading
• Define/delineate unsuitable material
• Define/delineate shallow bedrock conditions
• Rip-ability of dense soil/bedrock via Seismic Refraction Studies
• Stabilizing of soft/unstable subgrades
• Dewatering recommendations
• Retention System Requirements and Design Parameters
• Surcharging to reduce floor and foundation settlement

Not all floor slabs are the same.  Floor slab performance is a function of the slab’s structural capacity and how it interacts with the earth.  Foundation Design, P.C. analyses the in-place subsurface conditions and the floor loads anticipated, developing a Modulus of Subgrade Reaction for the anticipated conditions to help the designers develop an economical slab design.  Where required, we notify the design team that the earth is not capable of providing adequate floor performance and that structural floor slabs and/or sub-floor drainage systems may be required:

• Site Preparation Requirements
• Modulus of Subgrade Reaction
• Sub-floor Drainage Requirements
• Slab-on-Grade versus Structural Slab/Geo-joist Systems
• Surcharging to reduce floor settlement

Where sharp grade transitions are present, retaining walls are installed to hold back the earth.  Foundation Design, P.C. develops soil parameters for use in the designing both temporary and permenant retention structures, including lateral earth pressures, soil unit weights, angle of internal friction, and  allowable overturning toe pressures.  We assess/develop soil parameters for MSE and large block gravity walls and provide recommendations for foundation drainage.  Where required, our staff consults on the need for damp-proofing and/or water-proofing of below-grade construction:

• Lateral earth pressures
• Sliding Coefficients
• MSE Wall Parameters
• Block Gravity Wall Parameters
• Waterproofing/Damp-proofing Requirement
• Foundation Drains
• Sheet Piling and Soldier Pile & Lagging Systems

Our holistic philosophy extends into consultation on pavements, where significant interaction with the earth occurs.  For new projects, Foundation Design gathers subsurface data required to assess how the soil will perform under your traffic loads (including CBR tests), developing a recommended pavement section to be installed.  These sections range from Standard Duty Pavement Sections to be used in customer/ employee parking areas, Heavy Duty Pavement Sections to be used in high traffic areas and access drive lanes, and Rigid Pavement Sections to be used in areas where repetitive traffic occurs (drive-thru lanes, loading docks, dumpster locations).  We recognize that the three keys to good pavement performance are drainage, drainage, and drainage; accordingly, we consult with the design team to verify that adequate drainage systems are incorporated into the final plans:

• Perform PASER Analysis of pavement surface conditions
• Develop a pavement core exploration program
• Assess in-place pavement sections and provide recommendations for rehabilitation or reconstruction
• Subgrade preparation requirements, including undercutting
• Develop new pavement sections for parking lots, heavy duty/truck drive lanes, and roadways
• Pavement Slopes, Edge Drains, Underdrains, Weeps off Catch Basins

The International Building Code and State Building Codes contain provisions requiring seismic forces generated by the earth are resisted by the structural design.  Foundation Design, P.C. aids your structural engineer in designing for these seismic loads, assessing subsurface conditions and developing an appropriate Seismic Site Classification and spectral acceleration rates for the structural design.  Our engineering staff performs liquefaction analyses and can estimate the amount of liquefaction-induced settlement that may develop.  Where we determine that the earth warrants a more detailed analysis, a site-specific seismic shear wave analysis (MASW testing) can be performed to refine the Seismic Site Classification to help develop an economical seismic design:

• Seismic Site Classification
• Spectral Acceleration Rates
• Shear Wave Testing (MASW testing)
• Site Specific Analyses

The earth itself can create problems that impact your project.  Both native and man-made slopes can fail, creating significant soil movement and surface distress.  As slopes are designed, Foundation Design, P.C. reviews the proposed slope configurations using computer modeling to evaluate the internal stability and develop factors of safety for the proposed configuration.  Where requested, we can provide recommendations on safe slope configurations to maximize the developable area of your site.  

• Develop exploration/instrumentation programs to assess failed slopes
• Develop instrumentation monitoring programs to assess slope movement
• Perform 2-D engineering analysis of slope stability