Published: July 15, 2022
Provide all geotechnical information as required to complete the project planning and design in accordance with the Project Development Process, or as directed by ODOT. Provide an electronic copy of all geotechnical submissions to the District Geotechnical Engineer. Clearly identify on every submission (reports, plan drawings, etc.), the geotechnical specification (title and date) under which the geotechnical work was contracted and performed. Label the first complete version of all documents being submitted as “draft”. Subsequent to ODOT review and approval, submit a complete version of the document, revised as necessary, and label “final”.
Submit electronic copies of all final Geotechnical Exploration plan sheets in accordance with Location & Design Manual Volume 3, Section 1201. Geotechnical Exploration plan sheets include Geotechnical Profile – Roadway sheets, Geotechnical Profile – Structure sheets, and Geotechnical Profile – Geohazard sheets. When submitting the final Geotechnical Exploration plan sheets, also submit final boring data in electronic format for inclusion in the ODOT Geotechnical Data Management System (GeoMS). All boring data shall be compliant with the Data Interchange for Geotechnical and Geoenvironmental Specialists (DIGGS) standard. Logs prepared using the latest ODOT gINT library will meet this requirement. Submittal of gINT project files that can then be successfully auto-converted to DIGGS format by ODOT is acceptable. Additional information on DIGGS can be found online.
Provide a black & white pdf file of all Geotechnical Profile sheets, except provide color versions of sheets presenting ODOT Rock Core Photograph Report pages. See Section 702.6.5 and Appendices C and D for additional information.
702 Geotechnical Profile - Roadway
Present roadway and subgrade explorations as plan drawings in the form of a Geotechnical Profile - Roadway. If the project includes structures, present all structure explorations in the Geotechnical Profile - Roadway as well. Do not create separate plan sheets for structure explorations. A sample Geotechnical Profile is provided in Appendix D. Use the form of presentation and include the features described below:
702.1 Form of Presentation
Conform to the ODOT CADD Engineering Standards Manual regarding the size, format, lettering, and file management for the plan sheets. A listing of sheet title examples is provided in Appendix D.
For cover sheets and laboratory test data sheets use a scale of 1”=1’. For projects, or individual alignments, less than 1500 feet in length, use the largest standard horizontal scale (1”=5’, 1”=10’, 1”=20’, 1”=25’, 1”=40’, 1”=50’) appropriate to present the entire plan and profile on one sheet. For projects, or individual alignments, greater than 1500 feet in length, use a scale of 1”=50’ (or 1:500). A vertical scale of 1”=10’ (or 1:100) is required.
Plot all cross sections to the same horizontal and vertical scale. Use a scale according to the ODOT Location and Design Manual, Volume 3, Section 1310.2, except that a scale of 1”=20’ (or 1:200) is allowed for higher or wider slopes. A 1”=10’ scale is preferred. Plot more than one cross section per sheet if space permits.
702.3 Cover Sheet
Include the following information on the cover sheet of the Geotechnical Profile:
702.3.1 General Information
Include the following information in written text on the cover sheet:
- Project Description: A brief description of the project. Include the bridge number (i.e., FRA-71-0025) of each bridge included in the plan set, if any.
- Historic Records: Identify historic geotechnical explorations referenced in this exploration. State if no historic records are available.
- Geology: Provide generalized information about the project area, such as the terrain (i.e. Physiographic Region general description), soil origin (i.e., lacustrine, clayey or glacial till, outwash, alluvial, residual soils, colluvium), relative thickness (thin, thick, deep), any feature relative to the soils (i.e., buried valleys, boulder belts, peat deposits), bedrock type(s) and age (i.e., Berea Sandstone of Devonian Age or shale, sandstone, claystone, coal and limestone of Pennsylvanian aged Conemaugh Group)
- Reconnaissance: A brief presentation of site geology and topographical information as derived from the field reconnaissance notes. Include any site surface features of geotechnical importance. Comment on the good or bad performance of slopes, any structures, or pavement. Identify historic geotechnical explorations referenced in this exploration. Make sure date and personnel who performed field reconnaissance is listed.
- Subsurface Exploration: A brief description of the test boring and sampling methods. Include the date of last calibration and drill rod energy ratio as a percent for the hammer system(s) used. If multiple drill rigs are utilized, provide information for each rig.
- Exploration Findings: A summary of soil, bedrock, and groundwater conditions encountered and a generalized interpretation of the findings.
- Specifications: A statement of which version (date) of the SGE specifications the exploration was performed in accordance with. This should be the date of program planning.
- Available Information: Provide statement that “The soil, bedrock, and groundwater information collected for this subsurface exploration that can be conveniently displayed on the geotechnical profile sheets has been presented. Geotechnical reports, if prepared, are available for review on the Office of Contract Sales website.”
- A list of the initials of the personnel and the dates they performed a field reconnaissance of the site, the subsurface exploration (i.e., drilling), and the preparation of the Geotechnical Profile. If these tasks were performed over a period of many days, present the range of dates during which the tasks were performed.
Include a legend on the cover sheet of the drawings which contains the following information:
- Soil and Rock Symbology. Show and define only the symbology for soil and bedrock types that appear in the Geotechnical Profile. Use the symbology and descriptions for soil and bedrock types as presented on the Soil and Rock Symbology chart presented in Appendix D.
- Miscellaneous Symbols. Show and define all miscellaneous symbols and acronyms used on any of the Geotechnical Profile sheets. Do not list symbols that were not used.
- Number of Tests. Identify the numbers of soil samples for each classification that were mechanically classified and visually described. Do not include test results of historic geotechnical explorations in this number of tests, but calculate and show these results in a separate table.
702.3.3 Location Map
Include a map showing the general location of the project, with the beginning and ending stations indicated. Size the map as defined in the ODOT Location and Design Manual, Volume 3, Section 1302.8, Location Map.
702.3.4 Index of Sheets
Identify, in a table, the station limits for each plan and profile sheet and cross section sheet for projects greater than 1500 feet in length, having multiple alignments, or if cross sections are used.
702.3.5 Index of Bridges
Identify, in a table, the list of bridges for which structural foundation explorations were performed.
702.3.6 Testing for Scour Analysis
If sampling and testing for a scour analysis was performed, present this data, including D50 (metric units), Critical Shear Stress (τc), and Erosion Category (EC), using metric units for the diameter, on the cover sheet in tabular form if space permits, otherwise present this data on a new sheet after the boring log sheets. Only show the results if the final foundation design requires scour analysis.
702.3.7 Summary of Soil Test Data
Show a summary of test data for all roadway and subgrade boring samples on the cover sheet if all the test data fits on the front sheet, otherwise, present on additional sheets. Rotate summary table 90° when warranted to maximize number of borings presented on the additional sheets.
Display the data by roadway and subgrade borings in ascending stationing order for each roadway. When borings from historic geotechnical explorations are being used, include their test data in a separate table and make a note as to its source. Provide the exploration identification number and centerline or baseline station and offset of each boring. For each sample, record the following:
- The sample depth interval.
- Sample number and type, for example, SS-1, SS-2, ST-3, SS-4, etc. Do not repeat sample numbers in the same boring.
- Percent recovery.
- Hand Penetrometer.
- The percentage each of aggregate, coarse sand, fine sand, silt, and clay size particles; the liquid limit, plastic limit, plasticity index, and water content, all rounded to the nearest whole percent or number, for those samples mechanically classified.
- The classification of the soil by the ODOT Soil Classification Method as described in Section 600, including the Group Index in parentheses.
- A visual description of those samples not mechanically classified by the ODOT Soil Classification Method, including water content and the estimated ODOT Classification with “Visual” in parentheses. Reference to a mechanically classified sample, for example, “SAME AS SS–10” is satisfactory in lieu of a visual description.
- Sulfate Content Test Results
702.4 Presentation of Undisturbed Test Results
Display any undisturbed test results in graphical format on the sheets prior to the presentation of the surface and subsurface data.
702.5 Presentation of Surface Data
Prepare a roadway plan drawing showing the existing surface features, the proposed construction, and exploration locations. Include the following information on the drawing:
702.5.1 Existing Surface Features
Show the locations and limits of existing surface features, in general conformance with the ODOT Location and Design Manual, Volume 3, Section 1309.3, except no utilities shall be shown. Show additional surface features, such as, but not limited to:
- Poorly performing pavement sections
- Rock outcrops
- Uncontrolled fills, dumps, waste pits, excavations
- Low-lying poorly drained areas, swamps, bog areas, lakes, ponds, abandoned streams, existing streams, and intermittent streams
Identify existing land usage, such as, but not limited to:
- Wooded areas
- Grazing land
- Cultivated land
Identify the type, limits, and locations of geohazard features, such as, but not limited to:
- Mine areas
- Karst features
Use appropriate symbols and labels as defined in the ODOT CADD Engineering Standards Manual. Otherwise, identify features with text and boundary limits as necessary.
702.5.2 Proposed Construction
Show the proposed construction, in general conformance with the ODOT Location and Design Manual, Volume 3, Section 1309.4.
702.5.3 Exploration Locations
Show locations of project, instrumented, and historic borings with appropriate exploration symbols, as defined in the ODOT CADD Engineering Standards Manual, and corresponding exploration identification numbers according to Section 303.2. Where borings are not shown in profile on the same sheet, indicate the sheet where the graphical boring log can be found. Boring targets should be aligned with the centerline or baseline of reference. Do not show locations where only pavement cores were performed.
Include notes regarding observations not readily shown by drawings.
702.5.5 Surface Contours
As a minimum, present existing ground surface major contours developed for the design project. Present the minor contours if doing so does not compromise the presentation of other geotechnical information or topographic features. Showing both major and minor contours is preferred for geohazard explorations.
702.5.6 Cross Section Index
On each sheet, present a cross section index of sheets where cross sections within the station limits presented on that sheet can be found.
702.6 Presentation of Subsurface Data
Present the roadway subsurface data in the form of a profile along the centerline or baseline and on cross sections, when applicable.
Plot graphical boring logs to a vertical scale only. Indicate the location and depth of borings by means of a heavy dashed vertical line. Present the exploration identification number above the boring. Indicate soil and bedrock layers by symbols 0.4 inches in width and centered on the heavy dashed vertical line where possible. Use 0.4-inch wide symbols for bedrock exposures as well, except, do not include a heavy dashed vertical line. Use the symbols shown on the Soil and Rock Symbology chart in Appendix D. Ensure that a graphical boring log for every project boring appears at least once in the sheets, either in a profile or cross section view.
Show borings from historic explorations in the same manner as described above and present the exploration identification number above the graphical boring log.
702.6.1 Profile View
Show the proposed grade line, the existing ground profile, and information disclosed by borings and testing on the profile view. Display the existing ground line and the proposed grade line according to the ODOT CADD Engineering Standards. Do not show curve data. Indicate the offsets of borings with respect to centerline or baseline immediately above the borings shown on the profile. Reference borings located immediately adjacent to the centerline or baseline and considered representative of centerline or baseline subsurface conditions directly to the centerline or baseline. Present offset borings on cross sections.
702.6.2 Cross Sections
Cross sections provide the opportunity to conveniently show a wealth of additional information not available in a profile view. Prepare cross sections to show subsurface conditions disclosed by a series of borings drilled transverse to centerline or baseline using the following guidelines:
- For projects where only pavement widening is proposed, and no profile view is presented on the Construction Plan, present all borings on cross sections.
- Present all cross sections analyzed in design in the Geotechnical Profile.
- Plot offset borings on cross sections. Include centerline borings drilled at or near the same cross section, regardless of whether they are presented in the profile view
Display the existing and proposed ground lines according to the ODOT CADD Engineering Standards. Indicate the station of borings with respect to centerline or baseline immediately above the borings shown on the cross section. Bedrock exposures shown on cross sections may be plotted along the contour of the cross section.
702.6.3 Graphical Boring Logs and Bedrock Exposures
Show the following information adjacent to each graphical boring log or bedrock exposure, when applicable:
- The thickness, to the nearest inch, of any shallow surface material such as sod, topsoil, asphalt, concrete, aggregate base, uncontrolled fill, or peat, written immediately above the boring.
- Top of rock indicated at the elevation by a line with “TR”.
- The numeric value, to the nearest whole percent, of the moisture content of each sample tested, placed with the bottom of the text aligned with the bottom of the sample, immediately adjacent to the boring. Present this information on the right side of the graphical boring log if space allows. Identify this column at the bottom of the boring with the label “WC” (water content).
- N60, placed with the bottom of the text aligned with the bottom of the sample, immediately adjacent to the boring. Also show the refusal blow counts as uncorrected blows and if the penetration is less than 6” then show the penetration in inches. Example format is shown in the sample plans in Appendix D. Present this information on the left side of the graphical boring log if space allows. Identify this column at the bottom of the boring with the label “N60.”
- Free water indicated at the elevation encountered during the drilling process by a medium weight horizontal line with the letter "w" attached, water level measured at the end of drilling by an open equilateral triangle, point down, and water level measured after drilling completion with time identified and a shaded equilateral triangle, point down. Present this information on the same side of the graphical boring log as the moisture content, if space allows.
- When in place bedrock is encountered, provide a complete geologic description of each bedrock unit. When testing is performed (for example, point load strength index, SDI, and compressive strength), provide test results. When rock core is obtained, include unit recovery and unit RQD values within the description. Use headings or footings for clarity as necessary. If there is not sufficient room to present these descriptions on the same sheet, present them on a subsequent(s) sheet(s). Do not present a complete geologic description of each bedrock unit for structure or geohazard borings for which this information is presented on the boring log as described in 703.3.
- Visual description of any uncontrolled fill or any interval not adequately defined by a symbol on the graphical borings.
- Indication of organic content using the modifiers listed in Section 603.5. Include results for loss on ignition, for example, moderately organic (LOI=5.1%).
- Each moisture content of a plastic soil that is equal to or greater than the liquid limit minus three, designated by a 1/8-inch (3-millimeter) solid black circle placed immediately adjacent to the moisture content value.
- Each moisture content of a non-plastic soil either greater than or equal to 25 percent, or greater than or equal to 19 percent but appearing wet initially, designated by an open 1/8-inch (3-millimeter) circle with a horizontal line through the circle placed immediately adjacent to the moisture content value.
- The reason for discontinuing a boring before reaching the planned depth indicated immediately below the boring. If the reason was because of the use of hand equipment, indicate this, for example, "Refusal-Hand Auger.”
702.6.4 Boring Logs
Show the boring logs of all structure borings and any roadway borings drilled in the vicinity of the structure on the boring log sheet(s) following the plan and profile sheet(s). Create the boring logs in accordance with Section 703.3.
702.6.5 Rock Core Photographs
When a project includes rock coring, show the core photographs following the plan and profile sheet(s) or boring log sheet(s) when present. Take photographs as described in 409.2 and insert into the ODOT Rock Core Photograph Report provided in Appendix C. Place a maximum of 2 reports on one geotechnical profile sheet.
703 Geotechnical Profile - [Structure]
Present the geotechnical exploration involving structures only (i.e., no roadway), including bridges, culverts, retaining walls, and noise walls, as plan drawings in the form of a Geotechnical Profile – [Structure]. Structures explored as part of the same construction project may be presented together under the same cover sheet. A sample Geotechnical Profile – [Structure] is provided in Appendix D. Use the same form of presentation and features to be included as described in Section 702, except as noted below:
703.1 Cover Sheet
Do not prepare a Summary of Soil Test Data or an Index of Sheets. If sampling and testing for a scour analysis was performed, present this data, using metric units for the diameter, on the cover sheet in tabular form if space permits, otherwise present this data on a new sheet after the boring log sheets.
703.2 Plan and Profile
Place the plan and profile views of the structure on a subsequent sheet(s), following the cover sheet. Show the plan and profile sheet(s) at the same scale as the Site Plan for the proposed structure when possible. Show the existing and proposed profiles and the locations of the proposed structure foundation elements on the profile view. Information regarding the preparation of Site Plans is contained in the ODOT Bridge Design Manual, Section 200. Do not present a complete geologic description of each bedrock unit on the profile, rather, present this information on the boring log as described in 703.3.
For culverts present the plan and profile along the flowline of the culvert.
703.3 Boring Logs
Show the boring logs of all structure borings on the boring log sheet(s) following the plan and profile sheet(s). Create the boring logs in the same format as those presented in the sample Structure Foundation Exploration in Appendix D. Boring logs may be created using the boring log report forms in the Office of Geotechnical Engineering gINT library (oh dot.glb), found online.
For boring log sheets use a scale of 1”=1’. The maximum depth of a boring log on a single sheet shown on a plan sheet should be limited to 60 feet. Develop the boring logs by integrating the driller's field logs, laboratory test data, and visual descriptions. Include the following information on the boring logs:
Include the following in the heading:
- Exploration identification number
- Project designation (C-R-S) and PID
- Structural File Number (if applicable) and project type. Note if the structural file number listed is existing (E) or proposed (P)
- Centerline or baseline name, station, offset, and surface elevation
- Coordinates, see Section 303.2
- Names of drilling, sampling and logging firm(s) and personnel
- Methods of drilling and sampling
- Name/type of drill rig and hammer system
- Date started and date completed
- Date of last calibration and drill rod energy ratio (ER) in percent for the hammer system(s) used
- Boring completion depth
703.3.2 Boring Information
Include the following on the boring log:
- A depth and elevation scale
- Indication of stratum change
- Description of material in each stratum with hatching that represents the primary material or design stratum
- Depth of bottom of boring
- Depth of boulders or cobbles, if encountered
- Caving depth
- Water level observations including time of measurement reported in hours when applicable
- Artesian water and height of rise
- Heaving sand with location and height
- Cavities or other unusual conditions
- Method and material (including quantity) used for backfilling or sealing, including type of instrument installation, if any
- Depth interval represented by sample
- Sample number and type (restart sampling numbering for each boring)
- Percent recovery for each sample
- Measured blow counts for each 6 inches of drive for split spoon samples, numeric entries only
- N60 to the nearest whole number
- Hand penetrometer and/or torvane test results
- Particle-size analysis
- Liquid limit, plastic limit, plasticity index
- Water content
- ODOT soil classifications, with “V” in parentheses for those samples that are not mechanically classified
- Top of bedrock and bedrock descriptions of all in place bedrock encountered
- Run rock core percent recovery
- Run RQD
- Unit rock core percent recovery
- Unit RQD
- SDI, if applicable, with lithology described for any interlayered unit
- Compressive strength test results, if applicable, with lithology described for any interlayered unit
For borings drilled through a bridge deck, do not present the bridge deck and void from the bridge deck to the ground line in the Material Description and Notes column of the log. Instead, start the boring log at the ground surface/bottom of the stream and indicate in the Notes Section that the boring was drilled through the bridge deck, and what the bridge deck elevation is.
703.4 Presentation of Undisturbed Test Results
Display any undisturbed test results in graphical format on the sheets prior to the presentation of the surface and subsurface data.
704 Geotechnical Profile - [Geohazard]
Present the geotechnical exploration for geohazards as plan drawings in the form of a Geotechnical Profile – [Geohazard]. Use the same form of presentation and features to be included as described in Section 703, except present the scales and cross sections as described in Section 702.2. Identify the geohazard type(s) (landslide, rockfall, abandoned underground mine) in the title block.
705 Geotechnical Design Memorandum
All subsurface explorations will result in a single report for the project, containing a comprehensive account of the exploration and all geotechnical recommendations, as described in Section 706. Many projects include both roadway and structures for which design recommendations are needed at various points along the project development process. If a project includes multiple design features, such as roadway, bridges, culverts, noise walls, retaining walls, etc. and it is necessary to present recommendations individually for one of these features during the project design process, prior to the completion of the final report, do so in the form of a Geotechnical Design Memorandum. The Design Memorandum is to be clear and concise, presented in a letter format with supporting documentation attached, such as boring logs, calculations, etc. Issue Design Memorandums as required, numbered sequentially, and titled appropriately for the content of the memorandum.
706 Report of Geotechnical Exploration, Findings and Recommendations
Present a report of the geotechnical exploration and findings along with analyses and recommendations in a written text format. Identify the project PID and contact person (with contact information). Include the report in the appropriate planning/design step submission according to the ODOT Location and Design Manual, Volume 3 and the ODOT Bridge Design Manual. For all other reports, present information using the following headings and directions:
706.1 Report Title
Depending on the contents of the report, use one of the following titles:
- Roadway Exploration
- Structure Foundation Exploration
- Geohazard Exploration – (Identify Type of Geohazard)
706.2 Executive Summary
Present a brief summary of the findings and recommendations at the front of the report. List specific recommendations that will result in a deviation from the ODOT Construction and Material Specifications or from standard earthwork practices for the project.
Describe the project, including the project limits, and a description of the geotechnical report being submitted.
706.4 Geology and Observations of the Project
Provide a description of the general geology and hydrogeology, listing sources of information. Present field and office reconnaissance notes, emphasizing geotechnical features of interest.
Describe the exploration performed, including the following:
- List of projects from which historic boring programs were referenced and included
- Project exploration program
- Boring method(s) or other type of exploration method(s)
- Sample method(s) and intervals
- Laboratory testing program
Describe the geotechnical conditions revealed by the borings or other exploratory method(s). Give a description of the topography, drainage features, geology, and any other factors that might affect the design and construction of the project in the report. Also, identify areas where remedial measures may be required due to soft subgrade, soft embankment foundation, stability problems, settlement, or other concerns.
706.7 Analyses and Recommendations
Clearly document analyses which have been performed in order to develop recommendations regarding stability, settlement, and/or structure foundations. Include a diagram(s) showing the section(s) analyzed. Present calculations in a logical format in the appendix, as noted below. Describe how soil and bedrock parameters used in the analyses were determined. Acknowledge and explain any discrepancies between these parameters and field or laboratory test data.
Incorporate special drawings relating to stability, settlement, or foundation analysis of a size that produce a clear presentation and permit compact and neat folding for inclusion into the report.
Present recommendations as described below for each report type. Do not restate ODOT Construction and Material Specifications; include only recommended exceptions.
706.7.1 Roadway Exploration
Prepare recommendations related to the design and construction of the roadway that include any remedial measures necessary to complete the project. Provide specific treatment of soft foundation areas, design of cut slopes, drainage considerations, embankment design related to stability or settlement, construction sequence, instrumentation, field controls, and any other design factors affecting the project.
Be specific in the recommendations, noting the areal extent (by station and width) and depth of all required remedial earthwork measures. Likewise, be specific regarding locations concerning cut and fill slope recommendations. Non-specific recommendations are not acceptable.
Prepare recommendations related to the pavement design and subgrade support parameters and construction of the roadway subgrade in accordance with the Geotechnical Design Manual, Section 600. Present a Subgrade Analysis spreadsheet in the report. Provide specific treatment of unstable subgrade. Be specific in the recommendations, noting the areal extent (by station and width) and depth of all required remedial earthwork measures. Also identify limits of unsuitable subgrade. Non-specific recommendations which state, for example, to "undercut soft subgrade where it occurs,” are not acceptable.
706.7.2 Structure Foundation Exploration
For recommendations related to the design and construction of structures, include all design details, plan notes and construction constraints necessary to complete the project. Consider all available geotechnical information, including historic explorations, in formulating the design recommendations. Provide foundation or pile type, treatment of the foundation, allowable bearing of spread footings, design of piles and their estimated length, footing elevations, construction sequence, instrumentation, field controls and any other design factors affecting the project. Non-specific recommendations will not be accepted.
Present a statement of the parameters used in the analysis of the foundation design, such as those related to bearing capacity and settlement. Show the method of analysis and diagram of the section analyzed. Consider each pier and each abutment individually. Give consideration to the effect of approach embankment loadings on the piers and abutments.
706.7.3 Geohazard Exploration
Present a list and description of alternatives considered for the remediation of the geohazard. Include a cost estimate for each alternative. Present a recommended preferred alternative.
Present the following information in the appendices to the report.
706.8.1 Boring Plan
Present a site plan showing all boring locations. Present the plan in a scale that will allow the text to be legible but not spread the information out. Present a north arrow and a legend.
706.8.2 Boring Logs
Include boring logs as described in Section 703.3 in the report. The maximum depth of a boring log on a single 8-½” x 11” sheet should be limited to 30 feet, and the maximum depth of a boring log on a single 11” x 17” sheet should be limited to 60 feet. Present color pictures of rock cores immediately following the log. If the pages of rock core pictures exceed 20, only present the pictures on the electronic copy of the report.
Include particle size analyses gradation curves for scour samples only in the report.
706.8.3 Undisturbed Test Data
Report undisturbed test data as described below. Use the forms for undisturbed test reports presented in Appendix C.
- Unconfined Compression Test. Provide a report of the unconfined compression test according to AASHTO T 208 or ASTM D 2166 and include the following:
- Heading. Include project identification, boring number, station and offset, depth interval of sample, and sample number in the report heading.
- Graphical Data. Show a graph of the stress-strain relationship. Present an interpretation of the results including the maximum stress at the corresponding strain.
- Specimen Data. Show specimen data including dimensions of specimen, wet unit weight, dry unit weight, failure sketch to scaled size showing front and side views disclosing major crack patterns, description of material, particle- size analysis, liquid limit, plastic limit, plasticity index, moisture content.
- Triaxial Compression Test. Provide a report of the triaxial compression test according to AASHTO T 296 or T 297, or ASTM D 2850 or D 4767, and include the following:
- Heading. Include information according to Section 706.8.3.a (1) in the heading.
- Graphical Data. For each test specimen, show the relationship for the vertical stress versus strain and the pore pressure versus strain in graphical form. For the appropriate range of stress conditions selected, show the Mohr's stress circles based on total and effective stress. Provide an interpretation of the cohesion and friction angle from the data.
- Test Data. For each specimen, include moisture content, wet and dry unit weights, liquid limit, plastic limit, plasticity index, particle-size analysis, chamber pressures, and failure sketches to a scaled size showing front and side views disclosing major crack patterns. Record a description of the material and the type of triaxial test.
- Direct Shear Test. Provide a report of the direct shear test according to AASHTO T 236 or ASTM D 3080 and include the following information:
- Heading. Include information according to Section 706.8.3.a (1) in the heading.
- Graphical Data. Present normal pressure versus shear stress and shear displacement versus shear stress in graphical form, established on the basis of not less than three normal loads.
- Test Data. For each of the three specimens, include initial (wet) weight and volume of the specimen, wet unit weight, and moisture content. In addition, include the following information on one or more of the test specimens: liquid limit, plasticity index, and particle-size analysis. Record a description of the material and the type of test. Provide an interpretation of the cohesion and friction angle from the data.
- Consolidation Test. Provide a report of the consolidation test according to AASHTO T 216 or ASTM D 2435 and include the following information:
- Heading. Include information according to Section 706.8.3.a (1) in the heading.
- Pressure-Void Ratio. On the first sheet of the report, graphically present the pressure-void ratio relationship with void ratio plotted to arithmetic scale and pressure plotted to logarithmic scale for both the loading and rebound. Show the initial void ratio value at the start of the test on the margin of the graphical presentation.
- Time-Consolidation Curves. Present the time-consolidation curves for the last four loadings (not reboundings) of the specimen on supplemental sheets. Show consolidation in dial readings to the nearest 0.0001 inch, plotted to an arithmetic scale, with time in minutes plotted to a logarithmic scale or square root-of-time plotted to an arithmetic scale. Indicate the pressure for each curve. Show the entire curve of any one loading on a single sheet. Use abbreviated heading information on each sheet.
- Coefficient of Consolidation. Show the curve of the coefficient of consolidation on the same sheet as the pressure-void ratio curve. On this graph, plot the coefficient of consolidation to an arithmetic scale and plot the average pressure to a logarithmic scale.
- Data Sheet. For each consolidation test, include diameter, initial thickness, specific gravity, initial moisture content, initial void ratio, wet and dry unit weights, liquid limit, plastic limit, plasticity index, and particle-size analysis of samples. Include a description of the soil.
Present calculations in a logical format to support recommendations.
707 Method of Payment
Geotechnical Exploration Reports is an engineering service performed and paid for according to the engineering agreement and the Specifications for Consulting Services. The method of compensation for the work involved in Geotechnical Exploration Reports is actual cost plus a net fee.