Section 1 B. Geotechnical Considerations



B. Geotechnical Considerations


1. The Contractor shall be responsible for having determined to his satisfaction, prior to the submission of his bid, the nature and location of the work, the  conformation of the ground, the character and quality of the substrata, the types and quantity of materials to be encountered, the nature of the ground water conditions, the character of equipment and facilities needed preliminary to and during the execution of the work, the general and local conditions and all other matters which can in any way affect the work under this contract.  The prices established for the work to be done will reflect all costs pertaining to the work.  Any claims for extras based on substrata or ground water table conditions will not be allowed.

2. Information on subsoil conditions consisting of soil borings and environmental issues shall be included in the construction document. The Contractor shall perform any additional soil investigations he deems necessary at his own expense.

3. This material is made available as information only and solely for the convenience of bidders.  The Owner and/or the Consultant do not warrant or guarantee the accuracy of correctness of this material with respect to actual subsurface conditions.  The Contractor agrees that he will make no claims against the Owner and/or the Consultant if, in carrying out the work, he finds that actual conditions encountered do not conform to those indicated.

4. Geotechnical, Soil Testing and/or Lab Testing Services are required steps in the proper pre-planning of construction projects for the City.  Many of the City’s CIP and Public Works projects will require a Geotechnical, Soils or Lab Testing Report to validate either the City’s Engineer’s or any Architect’s or Engineer of Records recommendations as to any site, building or any other project’s unknown characteristics.

The City will be able to adequately plan and incorporate Geotechnical and Soil Testing Services as part of the pre-construction preparatory work, which is a phase that is part of every City construction project. 


Geotechnical Services

A. The Consultant shall provide all labor, materials, equipment, transportation, and other appurtenant work for performing subsurface explorations, obtaining representative samples, and performing all other geotechnical services.

B. The Consultant shall comply with all federal, state, and local rules and regulations with regard to permits, bonds, drilling, plugging, and all other applicable aspects of drilling.

C. The Consultant shall research and review all pertinent existing geologic and geotechnical data and information available from USGS, area development, and the company’s own files.

D. The Consultant shall review the proposed project information and requested scope of work indicated as a minimum level of services desired relative to the anticipated subsurface conditions present.  If localized subsurface conditions are expected to vary significantly, Consultant shall advise Owner of additional recommended services prior to commencing work.

E. The Consultant shall be responsible for contacting the appropriate agencies (state/city utility check) for determining locations of utilities in the vicinity of the actual boring locations.

F. Borings shall be backfilled to the original ground surface in accordance with all applicable local, state, and federal guidelines.

G. Consultant shall perform the standard penetration test (SPT) in accordance with ASTM Designation D 1956.

H. In soil that is predominantly cohesive (silty clays, sandy clays, and material with adhesive binder), Consultant shall use the thin-walled tube method for sampling in accordance with ASTM Designation D 1587.

I. Rock coring shall be performed in accordance with ASTM Designation D 2113.

J. Double-ring infiltration test shall be conduced in accordance with ASTM Designation D 5093.

K. Laboratory tests shall be assigned and performed b the Consultant to classify soils and obtain geotechnical physical characteristics such as strength, compressibility, swell potential, compaction characteristics, and chemical characteristics such as corrosiveness.  Perform laboratory resting consistent in quantity and quality with local geotechnical engineering practice to provide the required design parameters and recommendations.  The quantity of tests to be performed will be dependent upon the type of soil and/or rock encountered during drilling and sampling with additional consideration of the foundation types that may be required to support the proposed structures.

L. The Consultant shall prepare a geotechnical engineering report containing a discussion of the proposed construction, final boring logs, boring location plan, a description of the drilling and sampling program, a description of the geology and subsurface conditions encountered, groundwater conditions, laboratory test results, and foundation and earthwork recommendations and design parameters.

The following is a list of major items that shall appear in the geotechnical engineering report:

  • Previous Construction Activity and Existing Fill (if present):  A discussion of previous construction activity shall address any existing fills or subsurface openings, if encountered.  Outline the engineering properties of any existing fills with regard to foundation design.
  • Subsurface Conditions:  Subsurface conditions encountered at the site shall be discussed, based upon stratigraphic sequence observed and local geology.  Figures shall be provided displaying soil borings and generalized cross sections.  A general description of the engineering properties or parameters determined from the investigation and applied to design recommendations shall be provided.  Prevailing groundwater elevations observed and those recommended for design shall be noted.
  • Site Preparation Recommendations:  Provide grading and site preparation recommendations taking into consideration the conceptual grading plan for the site.
  • Compaction Requirements:  The report shall contain detailed and specific criteria for acceptable embankment, fill, or backfill materials and address whether the available borrow material on site is suitable for general or structural fill.  The report shall contain recommendations for material usage at the site with regard to placement and compaction requirements as well as any recommended treatment.  Compaction criteria, including acceptable gradations, moisture control, compactive effort, and need for proofrolling shall be discussed, including criteria for both granular and cohesive fill, if applicable.  Preparation of subgrades for fill and backfill placement shall be discussed.
  • Foundation Design: The geotechnical engineering report prepared by the Consultant will be used to size and structurally design stable foundations for the structures.  To accomplish this task, the report shall contain recommendations in regard to the recommended foundation type for each structure, as loading and site conditions may require.

The report shall provide net allowable bearing pressures for shallow spread footings and mats, at recommended bearing depths, considering the types of materials supporting the mats, and note whether any overstressing is allowed under short-term loading such as dynamic, wind, or seismic loading conditions.  If over-excavation of unsuitable materials and backfill with structural backfill are required to improve the foundation soils to allow the use of shallow foundations, provide estimated vertical and horizontal extent of the over-excavation and structural backfill.  Provide estimated total and differential settlement for foundations using the recommended bearing pressures.  Provide an estimate of the time of settlement.  Note factors of safety included or recommended.  Provide recommendations for resistance to lateral loads, such as passive earth pressures and sliding friction for the base of foundations.  Provide recommended groundwater level for determination of buoyancy and means to resist buoyant forces, if needed.

Recommendations for deep foundations shall include diameter, depth, and any recommended installation requirements.  Provide allowable design loading capacities for vertical downward loading, vertical upward loading, and horizontal loading, as appropriate to the site conditions.

Provide design parameters for analysis of laterally loaded drilled piers and required input into lateral pile capacity software.  All factors of safety utilized in developing the allowable load capacities shall be outlined in detail.

  • Slope Stability and Excavations:  The report shall address the recommended inclination of both temporary excavation and permanent slopes.
  • Excavation Requirements:  If necessary, a section of the report shall address the excavatibility of the soils and rock which may be exposed during foundation excavation and site grading.  The effort and type of equipment utilized to perform excavations is dependent upon the size and depth of the excavation.  Thus, the discussion shall be in regard to area-type excavations and confined excavations, such as utility trenches.
  • Dewatering:  Conditions present at the site requiring groundwater control, dewatering, or surface drainage during excavation for mats, footings, and other construction shall be discussed.  Anticipated types of dewatering shall be described.  Special consideration to exposed sub-soils within the bottom of excavations during construction shall be addressed.
  • Corrosion Potential and Chemical Attack to Concrete:  An evaluation of representative subsurface materials shall be performed to provide laboratory test results for chemical constituents, specifically pH, chloride ion, soluble sulfates, and sulfides as well as electrical resistivity.  These parameters are required to evaluate the potential for corrosion to underground piping and grounding, and selection of cement type to resist potential sulfate attack.
  • Pavement and Roadway:  Provide typical pavement thickness suggestions in accordance with CMB standard details Roadway specifications.

Any other items of consideration as deemed necessary by the geotechnical company.

The geotechnical engineering report shall be prepared by or under the direction of a Registered Professional Engineer registered under the regulatory laws of the State of Florida.

Roadway Reports

Roadway reports shall include, but not be limited to:

  • Copies of SCS and USGS maps with project limits.
  • A report of tests sheet that summarizes the laboratory test results, the soil stratification (i.e., soils grouped into layers of similar material) and construction recommendations relative to the current Standard indices.
  • Estimated seasonal high and/or low groundwater levels, and review with respect to proposed pavement grades.
  • Recommend type of geosynthetic for various applications.
  • The Design LBR results from 90% and mean methods.
  • Permeability/infiltration parameters for water retention areas/exfiltration trenches/swales.
  • A description of the site and subsoil conditions, design recommendations and a discussion of any special considerations (i.e., removal of unsuitable material, recompression of weak soils, estimated settlement time/amount, groundwater control etc.)
  • An appendix which contains stratified soil boring profiles, laboratory test data sheets, Design LBR calculations/graphs, and any other pertinent information.

In addition to the roadway report, the Consultant will also provide stratified boring profiles to the Designer and review the entire set of plans for completeness before each submittal as requested by the Department.  The Consultant shall assist the Designer with detailing limits on the cross-sections of subsoil excavation.  Up to four draft roadway reports shall be submitted to the District Geotechnical Engineer for each review prior to incorporation of the Consultant’s recommendations in the project design.


The consultant is responsible for obtaining all required City of Miami Beach and any Miami Dade County Public Works permits, including but not limited to, MOT, excavations, dewatering, etc.  Additionally, if required, the consultant shall be responsible for all special events permits from the City of Miami Beach Public Works Department and Miami Dade County Police Department.