FE Civil Practice Question Solution included after investigation
CASE E-102 · FE

The Soil at 7 m That Carried 94.8 kPa, Not 134

Total overburden at 7 m was 134 kPa, but pore water carried 39.2 kPa. The soil skeleton carried only 94.8 kPa effective stress.

▶ INTERACTIVE CASE FILE • 5–10 MIN • CLICK TO INVESTIGATE

Inspect, commit, prove, fix, and sign off.

Case E-102 engineering failure visual
HOW THIS WORKS

Think like
a real engineer.

Follow the investigation process used in the field — in five guided steps.

1

Inspect

Review the problem, diagram, and evidence.

2

Commit

Choose your hypothesis.

3

Prove

Run calculations and test your idea.

4

Fix

Select and validate a safe correction.

5

Sign Off

See the full debrief and key takeaways.

Case Brief

SAME PRINCIPLES. HIGHER STANDARDS.
PROBLEM STATEMENT

A soil profile has 3 m of moist soil above the water table with unit weight 18 kN/m³ and 4 m of saturated soil below it with saturated unit weight 20 kN/m³. Take gamma_w=9.81 kN/m³. Determine total vertical stress, pore pressure, and effective vertical stress at 7 m depth.

Geotechnical Engineering Civil Design Verification Root Cause Analysis Safe Correction
E-102
INVESTIGATION WORKSPACE WORK THROUGH THE CASE — YOUR CHOICES MATTER.
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DEBRIEF (LOCKED)

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Find the root cause, confirm the fix, and see how this connects to the exam.

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CASE CLOSED · ENGINEERING VERDICT

What actually failed — and what should change.

What failed

Total stress was reported as effective stress.

What was missed

Pore-water pressure at 4 m below the water table.

Corrected model

Use sigma'=sigma-u.

QUICK ANSWER

sigma=3(18)+4(20)=134 kPa. Pore pressure u=4(9.81)=39.24 kPa. Therefore sigma'=134-39.24=94.76 kPa.

ENGINEERING TAKEAWAY

Use sigma'=sigma-u, with pore pressure based on depth below the water table.

CASE QUESTIONS

Questions this case should settle.

What is the effective stress equation?

sigma'=sigma-u.

NEXT FE PRACTICE QUESTION

The Footing That Held 614 kPa, Not 331

Geotechnical Engineering · 5–10 min

Continue Practice →
WHAT YOU’LL LEARN

Real failures. Lasting skills.

Each case is designed to build the judgment, analysis, and confidence you need for engineering exams — and beyond.

  • Apply core engineering concepts to real-world problems
  • Practice structured troubleshooting and analysis
  • Strengthen exam-ready thinking through realistic scenarios
COMMON QUESTIONS
Do I need prior knowledge to use these cases?

Basic subject familiarity helps, but every case is designed to teach through the investigation itself.

How long does a case take?

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Are the cases aligned with engineering exams?

Each case is mapped to a verified exam, subject, topic, and misconception before publication.

What happens after I complete a case?

The sealed debrief unlocks with the root cause, corrected reasoning, fix, and takeaway.