---
title: "Causes of foundation failure"
subject: "Building Technology"
chapter: 2
key: "semester_6/building_technology:foundation-failures"
source: https://www.bctengineer.com/q/semester_6/building_technology/foundation-failures
site: BCT Engineering
---

# Causes of foundation failure

Building Technology · Chapter 2: Foundations

- Asked in: 2075 Bhadra, 3 marks; 2073 Magh (asked 2 times)
- Video: [Foundation failure | Causes of foundation failure | Remedies for foundation failure | foundation](https://www.youtube.com/watch?v=MVPlLPCb8XE) — Civil Engineering Mastery
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_6/building_technology/foundation-failures
- Whole chapter: https://www.bctengineer.com/md/semester_6/building_technology/chapter-2

## Question

Describe the causes of foundation failure (list the common foundation failures).

## Short answer

Foundation failure stems from differential settlement due to uneven soil bearing, weak ground causing shear failure, consolidation of compressible soil, lateral soil movement, water table changes, expansive soil behaviour, tree root moisture extraction, poor construction, adjacent excavations, chemical attack, seismic activity, frost, and underground voids.

## Answer

Foundation failure means the foundation can no longer support the structure safely, because of shear failure of the soil or excessive (differential) settlement. Common causes are:

1. **Unequal bearing capacity or non-uniform soil** under different parts of the foundation, giving differential settlement.
2. **Weak or overloaded soil**: Bearing capacity less than the pressure applied; shear failure.
3. **Settlement due to consolidation** of clay or other compressible soil, and loss of soil by erosion.
4. **Lateral movement of soil** (sliding of sloping ground, squeezing of soft soil out from under the footing).
5. **Variation of water table** and flooding; withdrawal of ground water.
6. **Seasonal swelling and shrinkage** of expansive soils such as black cotton soil.
7. **Tree roots** drawing moisture from the soil near the foundation, causing shrinkage.
8. **Poor design and construction**: Inadequate depth, size, or concrete quality; construction on filled ground, poor compaction; unequal loading.
9. **Adjacent excavations or construction** removing lateral support.
10. **Chemical attack** (sulphates) and corrosion of the foundation.
11. **Earthquake and vibrations** causing liquefaction or compaction.
12. **Frost action** in cold areas.
13. **Underground voids** (mines, caves, leaking pipes).

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. What defines foundation failure?
   A. Cracking of paint
   B. Minor dust on footing
   C. Plaster peeling only
   D. Shear failure of soil or excessive differential settlement
   Answer: D. Failure means the foundation cannot support the structure safely. (Key point: Foundation failure)

2. How does black cotton soil cause failure?
   A. Constant strength
   B. Increased bearing in wet season
   C. Seasonal swelling and shrinkage
   D. Freezing only
   Answer: C. Volume change with moisture moves the foundation. (Key point: Expansive soil)

3. What does non-uniform soil under a foundation produce?
   A. Uniform settlement only
   B. No effect
   C. Increased bearing capacity
   D. Differential settlement
   Answer: D. Unequal soil gives unequal settlement. (Key point: Non-uniform soil)

## Related in Building Technology

- [Foundation settlement causes and treatment](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Afoundation-settlement-treatment) — Building Technology, chapter 2
- [Foundation settlement causes and underpinning](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Asettlement-underpinning-067as) — Building Technology, chapter 2
- [Common problems of existing foundations](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Aproblems-existing-foundation) — Building Technology, chapter 2, asked 2×
- [Foundation settlement, effects, black cotton soil](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Asettlement-black-cotton-062ba) — Building Technology, chapter 2
- [Foundation classification and problems](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Afoundation-class-problems) — Building Technology, chapter 2, asked 2×

## Related in other subjects

- [Common deficiency and failure under gravity, lateral loads](https://www.bctengineer.com/question.md?key=semester_5%2Fconcrete_technology_and_masonry_structure%3Adeficiency-failure-gravity-lateral) — Concrete Technology and Masonry Structure, chapter 9
- [Highway maintenance and causes of pavement failure](https://www.bctengineer.com/question.md?key=semester_7%2Ftransportation_engineering_ii%3Amaintenance-flexible-failures) — Transportation Engineering II, chapter 4, asked 2×
- [Causes of slope failure](https://www.bctengineer.com/question.md?key=semester_4%2Fsoil_mechanics%3Aslope-failure-causes) — Soil Mechanics, chapter 11, asked 4×
- [Maintenance vs rehabilitation; flexible failure causes](https://www.bctengineer.com/question.md?key=semester_7%2Ftransportation_engineering_ii%3Amaintenance-vs-rehabilitation-flexible-failure-causes) — Transportation Engineering II, chapter 4