This deliverable is not counted toward your grade
Project Start and Technical Implementation (site, data and investigation) pages are required practice but are not counted toward your final grade. Your engineering grade comes from Chapter 4 and Chapter 5.
Geotechnical Investigation
Students correct raw SPT blow counts to N60 and build a stratigraphic log used to estimate design soil parameters.
Section progress
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Field & Laboratory · Plan, execute and document field and laboratory data collection to a defensible quality standard.
Deliverable: Boring logs with N60/(N1)60 corrections and stratigraphic classification.
How to complete this section
Do this next: Read the Geotechnical Investigation lecture and the worked example so you know what "Boring logs with N60/(N1)60 corrections and stratigraphic classification." has to contain.
Not sure how to start or how much depth is expected? Read the fully written model example for this deliverable first — it shows the structure, tables and level of justification your advisor grades against.
Site Investigation Lab — what this workspace teaches
Plan, execute and document field and laboratory data collection to a defensible quality standard.
- Planning a subsurface, structural or traffic field investigation
- Instrumentation selection, resolution, accuracy and calibration records
- GPS/GNSS positioning: datums, projections, RTK vs. handheld accuracy
- GIS data capture, attribute schemas and coordinate metadata
- Land surveying: traverses, levelling, closure and error adjustment
- Sampling strategy: representative sampling, spacing, depth intervals, replicates
- ASTM/AASHTO laboratory testing procedures and reporting requirements
- Chain of custody, sample labelling and preservation
- QA/QC: duplicates, blanks, repeatability and data validation rules
End-of-term milestones
- Tuesday, November 17, 2026 — Poster printed and ready. 36 in × 48 in poster finalized and printed one week before the November 24 showcase.
- Wednesday, November 18, 2026 — Final document package uploaded for scoring. Chapters 4–5, calculation package, drawings and appendices uploaded in the app for advisor scoring.
- Wednesday, November 18, 2026 — Poster presentation to faculty and industry. Wednesday poster session — printed 36 in × 48 in poster presented in person; industry reviewers score communication and impact.
- Wednesday, November 25, 2026 — Oral presentation and defense (scored). Scored oral presentation and defense held on Wednesday, November 25.
Geotechnical Investigation
Students correct raw SPT blow counts to N60 and build a stratigraphic log used to estimate design soil parameters.
Section B
Engineering story
A real project situation that frames this module
It is week 3 of implementation and the geotechnical engineering team has reached geotechnical investigation. Students correct raw SPT blow counts to N60 and build a stratigraphic log used to estimate design soil parameters. The geotechnical reviewer for the owner asks one question: what establishes that sPT procedure and sources of energy loss requiring correction to a standard 60% energy ratio?
Using raw N-values directly in a bearing capacity correlation without energy correction. Because correction factors, the error does not stay local: it is carried into the data foundation every later calculation silently depends on, and every downstream product inherits it before anyone notices.
Adjacent property owners, excavation crews and the geotechnical engineer of record carry the consequence. On this module specifically, the exposure runs through overburden correction (CN) for comparing N-values across depth, and the cost of correction rises every week the subsurface interpretation and foundation recommendation moves closer to issue.
Decisions the engineer must make
- What record establishes sPT procedure and sources of energy loss requiring correction to a standard 60% energy ratio, and is that record in the project data inventory?
- Does ASTM D1586 (2018), Full standard, govern here — and is that the edition adopted by the jurisdiction?
- What is the acceptance criterion for correction factors, and was it written before the result was known?
- Is N60 = N·Em·CB·CS·CR / 0.60 valid over the parameter range this project actually occupies?
- If the check fails, does the team revise the subsurface interpretation and foundation recommendation or raise a change request against the locked baseline?
Photo 1. Subsurface investigation: SPT samples and the boring log that every geotechnical number traces back to.
Capstone Studio instructional photograph
Section C
Why this matters
Professional
A licensed engineer defending geotechnical investigation cites ASTM D1586 (2018), Full standard, and shows the record behind each input. Your boring logs with n60/(n1)60 corrections and stratigraphic classification. is reviewed the same way — traceability is assessed before arithmetic.
Technical
SPT procedure and sources of energy loss requiring correction to a standard 60% energy ratio is what makes N60 = N·Em·CB·CS·CR / 0.60 usable on this project rather than a formula copied from a reference. Get it wrong and every quantity derived from it is wrong by the same factor.
Safety
The failure mode this module guards against is settlement, bearing failure or slope instability below the finished grade. It reaches people through correlating corrected N60 to relative density, friction angle, or undrained shear strength, which is why the safety check is recorded explicitly here rather than inferred from a passing strength or performance check.
Economic
The data foundation every later calculation silently depends on is priced from this work. Quantities, unit costs and schedule float all trace to sPT procedure and sources of energy loss requiring correction to a standard 60% energy ratio; a late correction here is paid for as a change order, not a redline.
Environmental
Environmentally, this module fixes spoil handling, dewatering discharge and groundwater drawdown near the site. Choosing conservatively without justification is not free — the excess shows up as material, energy and land that the project consumes for no measurable gain.
Community
Neighbors whose structures, utilities and streets sit within the zone of influence inherit whatever this module decides — performance, accessibility, cost of ownership and resilience are set here, not at the ribbon-cutting.
Section D
Learning objectives
By the end of this module you will be able to:
- 1.Compare sPT procedure and sources of energy loss requiring correction to a standard 60% energy ratio, using this project's own conditions rather than a textbook case.
- 2.Analyze correction factors, using this project's own conditions rather than a textbook case.
- 3.Evaluate overburden correction (CN) for comparing N-values across depth, using this project's own conditions rather than a textbook case.
- 4.Interpret stratigraphic log construction from drive samples, visual classification, and moisture observations, using this project's own conditions rather than a textbook case.
- 5.Compute the governing quantity from N60 = N·Em·CB·CS·CR / 0.60 and (N1)60 = CN·N60, with a unit audit on every term.
- 6.Apply ASTM D1586 (2018), Full standard, and cite the section that governs your acceptance decision.
- 7.Reproduce the worked example for a boring records a raw SPT N = 18 at 4.5 m depth using a safety hammer (Em… and defend the interpretation of the result.
- 8.Produce boring logs with n60/(n1)60 corrections and stratigraphic classification. at a standard the geotechnical reviewer for the owner would accept without a second revision cycle.
Section E
Instructional content
Full lecture notes with figures and governing equations
The engineering content of geotechnical investigation
Students correct raw SPT blow counts to N60 and build a stratigraphic log used to estimate design soil parameters. That single sentence hides the substance of the module: sPT procedure and sources of energy loss requiring correction to a standard 60% energy ratio, and correction factors. Both must be established from project evidence before anything downstream is credible.
In geotechnical engineering, this work is the input to the subsurface interpretation and foundation recommendation. Overburden correction (CN) for comparing N-values across depth — which is why this page asks you to record the source of every quantity, not just its value. The data foundation every later calculation silently depends on depends on it.
- SPT procedure and sources of energy loss requiring correction to a standard 60% energy ratio
- Correction factors: hammer energy (Em), borehole diameter (CB), sampler type (CS), rod length (CR)
- Overburden correction (CN) for comparing N-values across depth
- Stratigraphic log construction from drive samples, visual classification, and moisture observations
- Correlating corrected N60 to relative density, friction angle, or undrained shear strength
Photo 1. The engineering content of geotechnical investigation in practice — Subsurface investigation: SPT samples and the boring log that every geotechnical number traces back to.
Capstone Studio instructional photograph
Governing relationships and how they are applied here
The relationships below govern geotechnical investigation. N60 = N·Em·CB·CS·CR / 0.60; (N1)60 = CN·N60 — each is valid only inside the parameter range this project occupies, so state that range before substituting.
Correction factors sets the values you place into these expressions. Any code-prescribed factor must match ASTM D1586 (2018); a factor lifted from a different edition silently changes the answer.
N60 = N·Em·CB·CS·CR / 0.60
- N = field-measured (raw) blow count
- Em = hammer energy efficiency ratio
- CB = borehole diameter correction
- CS = sampler correction
- CR = rod length correction
- 0.60 = reference energy ratio
(N1)60 = CN·N60
- CN = overburden stress correction factor
- N60 = energy-corrected blow count
Photo 2. Governing relationships and how they are applied here in practice — Subsurface investigation: SPT samples and the boring log that every geotechnical number traces back to.
Capstone Studio instructional photograph
Constraints, adopted standards and the safety case for geotechnical investigation
ASTM D1586 (2018), Full standard, governs this module: Standard test method for SPT and split-barrel sampling AASHTO LRFD Bridge Design Specifications (9th Ed.), Sec. 10.4, adds the second constraint: Use of corrected SPT data for foundation design parameters
The safety case is explicit here. The failure mode is settlement, bearing failure or slope instability below the finished grade; the people exposed are adjacent property owners, excavation crews and the geotechnical engineer of record; the control that prevents it is correlating corrected N60 to relative density, friction angle, or undrained shear strength together with an independent check by someone who did not perform the work.
- Controlling criterion for this module: sPT procedure and sources of energy loss requiring correction to a standard 60% energy ratio.
- Adopted reference: ASTM D1586 (2018) — cite Full standard by number.
- Failure mode guarded: settlement, bearing failure or slope instability below the finished grade.
- Evidence produced: Boring logs with N60/(N1)60 corrections and stratigraphic classification..
Photo 3. Constraints, adopted standards and the safety case for geotechnical investigation in practice — Subsurface investigation: SPT samples and the boring log that every geotechnical number traces back to.
Capstone Studio instructional photograph
Where this method stops being valid
The worked example — a boring records a raw SPT N = 18 at 4.5 m depth using a safety hammer (Em = 0.72),… — holds only while its assumptions hold. The corrections nearly offset (energy loss vs. short rod length), so N60 stays close to the raw value here — but this cannot be assumed for other rod lengths and must be computed explicitly for each boring depth. Outside that envelope the arithmetic still returns a number, and the number is wrong in a way no unit check will catch.
For this project, the boundary you are most likely to push is correlating corrected N60 to relative density, friction angle, or undrained shear strength. If you cross it, say so in writing, bound the error, and carry the limitation into your results chapter. A disclosed limitation is professional practice; a silent extrapolation is not.
Photo 4. Where this method stops being valid in practice — Subsurface investigation: SPT samples and the boring log that every geotechnical number traces back to.
Capstone Studio instructional photograph
Section F
Engineering workflow
Steps
- 1. Assemble the inputs this module needs — sPT procedure and sources of energy loss requiring correction to…; correction factors — each with a unit and a source record.
- 2. Confirm ASTM D1586 (2018) is the adopted edition and locate Full standard.
- 3. State the assumptions and the acceptance criterion for sPT procedure and sources of energy loss requiring correction to a standard 60% energy ratio.
- 4. Evaluate N60 = N·Em·CB·CS·CR / 0.60 and (N1)60 = CN·N60 term by term, carrying one extra significant figure.
- 5. Test the result against overburden correction (CN) for comparing N-values across depth.
- 6. Audit units and run an order-of-magnitude check by hand before the number leaves your desk.
- 7. Obtain an independent check from a teammate who did not perform the work, and record their name and date.
- 8. Assemble boring logs with n60/(n1)60 corrections and stratigraphic classification. and submit it to the geotechnical reviewer for the owner for review.
Decision points
- Is every input behind sPT procedure and sources of energy loss requiring correction to a standard… traceable? If not — stop and collect the record.
- Does the result satisfy correction factors? If not — revise the work, never the criterion.
- Would the correction change the data foundation every later calculation silently depends on? If yes — raise a change-control request before proceeding.
- Have you ruled out the most common error on this module — using raw N-values directly in a bearing capacity correlation without energy correction?
Quality checklist
- Documented: sPT procedure and sources of energy loss requiring correction to a standard…
- Documented: correction factors
- Documented: overburden correction (CN) for comparing N-values across depth
- ASTM D1586 Full standard cited by section number
- Units audited on every expression
- Acceptance criterion recorded before the result
- Independent check signed and dated
- Boring logs with N60/(N1)60 corrections and stratigraphic classification. attached and named per the course convention
Section H
Interactive visualization
Geotechnical Investigation — step-through
Advance one frame at a time. Each frame adds one engineering decision to the previous state.
Step 1 of 6
Drive the split-spoon sampler and record raw blow counts per 6-inch increment.
Section I
Applicable codes and standards
ASTM D1586
2018 · Full standard
Adopted design/analysis reference governing this module.
Relevance: Standard test method for SPT and split-barrel sampling
Reference the section number and edition in your calculation package. Do not reproduce code text.
AASHTO LRFD Bridge Design Specifications
9th Ed. · Sec. 10.4
Adopted design/analysis reference governing this module.
Relevance: Use of corrected SPT data for foundation design parameters
Reference the section number and edition in your calculation package. Do not reproduce code text.
Section J
Worked examples
Full engineering solution format
Section K
Common mistakes and how to avoid them
- Using raw N-values directly in a bearing capacity correlation without energy correction.
- Applying a single CR value to the entire boring instead of varying it with actual rod length at each depth.
- Misclassifying a silty sand as clay from visual inspection alone without Atterberg limits.
- Treating sPT procedure and sources of energy loss requiring correction to a standard 60% energy… as a given instead of establishing it from a project record.
- Producing boring logs with n60/(n1)60 corrections and stratigraphic classification. without showing how correction factors was satisfied.
- Substituting into N60 = N·Em·CB·CS·CR / 0.60 outside the range where it is valid, and reporting the number anyway.
- Missing correlating corrected N60 to relative density, friction angle, or undrained shear strength, which is exactly the path to settlement, bearing failure or slope instability below the finished grade.
- Collecting data before defining what decision the data has to support.
- Accepting a laboratory or field value without its method, date, operator and uncertainty.
- Leaving boundary conditions undefined so the model is not reproducible by an independent checker.
- Using inputs that no field record, laboratory report, or published source supports.
- Stopping at output and skipping verification — an unverified number is not an engineering result.
Section L
Industry case study
Documented failure related to geotechnical investigation
A constructed civil works project where this module's decision was made incorrectly or skipped.
Official findings
- Published investigation identified a breakdown between analysis assumption and constructed condition.
Field observations
- The controlling assumption was documented nowhere in the design record.
- No independent check existed at the stage where the error entered the work.
Engineering interpretation
- Interpretation below is student analysis for instructional purposes, not an official finding.
- Map the failure to a step in your own workflow and state where your process would have caught it.
Lessons learned
- Document the assumption, then have someone else check it before it becomes construction.
Source: Summarize the published investigation; cite it in your reference list. Do not reproduce copyrighted report text.
Section M
FE Civil exam connection
Handbook FE Reference Handbook — geotechnical engineering section (record the section number from your handbook edition).
Exam topics
Handbook formulas
- N60 = N·Em·CB·CS·CR/0.60
- (N1)60 = CN·N60
Weak results here feed your FE Civil Academy weak-area queue for targeted practice.
Question 1 of 2
Score: 0/2In geotechnical investigation, which item must be established BEFORE the analysis is run?
Section N
Apply it to your project — Geotechnical Investigation
Complete this using your own capstone project data. Every field is saved to your project record and routed to your advisor with this module's submission.
Inputs and sources
Every value needs a traceable source.
| Quantity | Value | Unit | Source / record |
|---|
Assumptions and consequences
| Assumption | Basis | Consequence if wrong |
|---|
Self-check before submission
Section O
Design challenge
Consulting challenge — Geotechnical Investigation
Your firm has been retained to deliver the geotechnical investigation scope for a municipal client on a compressed schedule. Produce the technical position your firm would defend at a public meeting.
Client request: The client wants a defensible recommendation, the basis of design, and an honest statement of what remains unresolved.
Constraints
- Adopted local code edition governs; no exceptions without written variance.
- Budget and schedule are fixed; scope changes require change control.
- Public safety and accessibility requirements are non-negotiable.
Deliverables
- One-page basis of design
- Supporting calculation extract
- Risk and limitation statement
Evaluation
- Technical correctness
- Standard compliance
- Clarity of engineering judgment
- Honest treatment of uncertainty
Section P
Documentation workspace
Write the report section for this module in the academic editor
Section Q
File uploads
Accepted: PDF, DOCX, XLSX, CSV, PNG, JPG, ZIP
No files uploaded yet.
Section R
Deliverable and advisor review
Boring logs with N60/(N1)60 corrections and stratigraphic classification.
Submissions route to your assigned faculty advisor and are scored independently by faculty and administrator rubrics.
Reflection
What was the hardest engineering judgment in this module, and how did you resolve it?
Section S
ABET outcome mapping
Boring logs with N60/(N1)60 corrections and stratigraphic classification. with advisor review and dual scoring.
Assessment: Faculty rubric score and administrator rubric score on this module's submission.
Rubric: Data quality · Target: 70% of students at or above 'meets expectations'.
Boring logs with N60/(N1)60 corrections and stratigraphic classification. with advisor review and dual scoring.
Assessment: Faculty rubric score and administrator rubric score on this module's submission.
Rubric: Data quality · Target: 70% of students at or above 'meets expectations'.
Section T
References and further study
ASTM D1586 (2018)
Adopted reference — cite section numbers, do not reproduce text.
AASHTO LRFD Bridge Design Specifications (9th Ed.)
Adopted reference — cite section numbers, do not reproduce text.
Geotechnical Investigation — instructor design procedure
Course template for the calculation package format expected in the final report appendix.
NCEES FE Reference Handbook
Locate the equations used here and note the handbook section for exam recall.
Advisor meeting agenda item
Bring the unresolved decision from this module to your next weekly advisor meeting.