ICC Soils Inspector EC cheat sheet

Site evaluation includes reviewing site plans, conducting a site visit, and documenting soil and site conditions that affect construction and stormwater management.

Soil borings or test pits must extend to a depth sufficient to evaluate the limiting layer, typically at least 5 feet below the proposed grade or to a restrictive layer.

The seasonal high water table is indicated by redoximorphic features (mottles) and must be determined to establish separation to the bottom of the infiltration system.

Slope is measured as vertical rise over horizontal run; slopes steeper than 15% often require special design or are prohibited for infiltration practices.

Depth to bedrock or impermeable layer must be verified; a minimum separation of 2 feet is commonly required between the bottom of an infiltration practice and bedrock.

Soil permeability is estimated from soil texture and structure; a percolation test or infiltration test may be required to confirm design rates.

Setbacks from property lines, wells, and foundations must be checked against local ordinances during site evaluation.

Documentation of site evaluation includes soil profile descriptions, photographs, and a site plan showing test pit locations and elevations.

Soil texture is determined by the relative proportions of sand, silt, and clay using the USDA textural triangle.

The Unified Soil Classification System (USCS) uses group symbols such as GW, SP, CL, and CH based on grain size distribution, plasticity, and organic content.

Atterberg limits (liquid limit, plastic limit, plasticity index) define the plastic behavior of fine-grained soils; PI = LL - PL.

Soil color, especially mottling, indicates drainage conditions; gray or bluish-gray colors with redoximorphic features suggest prolonged saturation.

Soil structure describes the arrangement of soil particles into aggregates (e.g., granular, blocky, prismatic) and affects permeability and root penetration.

The AASHTO soil classification system groups soils into A-1 through A-8 based on particle size, plasticity, and group index for highway subgrade evaluation.

Field identification of soil includes the ribbon test for clay content, the dilatancy test for silt, and the dry strength test.

Organic soils (peat, muck) are highly compressible and unsuitable for structural fill; they are identified by dark color, low density, and organic odor.

Standard Proctor (ASTM D698) uses a 5.5-lb hammer dropped 12 inches in 3 layers; Modified Proctor (ASTM D1557) uses a 10-lb hammer dropped 18 inches in 5 layers.

Maximum dry density and optimum moisture content are determined from a compaction curve; field density must be at least 95% of maximum dry density for most fills.

Field density testing methods include the sand cone (ASTM D1556), rubber balloon (ASTM D2167), and nuclear gauge (ASTM D6938).

The sand cone method requires calibrating the sand bulk density and determining the volume of the test hole.

Nuclear gauge testing measures wet density and moisture content; it must be calibrated and operated by a trained technician with proper licensing.

Compaction specifications often require a certain percentage of maximum dry density (e.g., 95%) and a moisture content within ±2% of optimum.

Test frequency is typically one test per lift per specified area (e.g., every 2,500 square feet) or as directed by the geotechnical engineer.

Acceptance criteria for compaction are based on the specified relative compaction and moisture range; failing tests require rework and retesting.

The inspector must verify that all required permits are obtained before construction begins and that the approved plans are on site.

Code administration includes maintaining records of inspections, test results, and correspondence for each project.

Stop-work orders may be issued when work is proceeding without a permit or when violations pose a threat to public safety.

Inspectors have the authority to enter premises at reasonable times to inspect and to require correction of code violations.

Appeals of inspection decisions are typically heard by a local board of appeals within a specified timeframe.

The code official may require special inspections by a qualified third party for certain elements (e.g., soil compaction, foundation excavation).

Penalties for code violations may include fines, revocation of permits, or legal action; the inspector documents violations and follows up.

Code administration requires knowledge of local amendments and the adopted edition of the International Code Council (ICC) family of codes.

Inspection reports must include date, time, project identification, inspector name, weather conditions, and specific observations with locations.

Photographs should be dated and referenced in the report to document conditions such as soil strata, compaction equipment, and test locations.

Nonconformance reports must clearly state the code or specification requirement, the observed condition, and the required corrective action.

Inspectors should verify that materials (e.g., backfill, geotextile) meet approved submittals before installation.

Field tests must be recorded with test method, location, results, and pass/fail determination; retests are required for failed tests.

Daily reports should note any deviations from approved plans and whether they were approved by the designer or code official.

Final inspection reports summarize all inspections, test results, and confirm that the work complies with the approved plans and code.

Reports must be retained for the period specified by the jurisdiction and made available for review upon request.