---
title: "Common deficiency and failure under gravity, lateral loads"
subject: "Concrete Technology and Masonry Structure"
chapter: 9
key: "semester_5/concrete_technology_and_masonry_structure:deficiency-failure-gravity-lateral"
source: https://www.bctengineer.com/q/semester_5/concrete_technology_and_masonry_structure/deficiency-failure-gravity-lateral
site: BCT Engineering
---

# Common deficiency and failure under gravity, lateral loads

Concrete Technology and Masonry Structure · Chapter 9: Masonry structures under lateral loads

- Asked in: 2082 Baisakh, 4 marks
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_5/concrete_technology_and_masonry_structure/deficiency-failure-gravity-lateral
- Whole chapter: https://www.bctengineer.com/md/semester_5/concrete_technology_and_masonry_structure/chapter-9

## Question

Explain common deficiency and failure in masonry structure under gravity and lateral load.

## Short answer

Under gravity: compression crushing, buckling, local bearing failure, differential settlement; deficiencies include weak mortar and poor bond. Under lateral: in-plane diagonal/shear failure, out-of-plane overturning and bending cracks; deficiencies are lack of bands, ties, large openings near corners, and weak connections.

## Answer

#### Under gravity (vertical) load

- **Compression failure:** crushing of units or splitting; vertical cracks (tensile splitting of bricks) when load is high or units/mortar are weak.
- **Buckling of slender walls and columns:** high slenderness ratio, large eccentricity.
- **Local bearing failure** under concentrated loads from beams and lintels; no bed block.
- **Differential settlement** causes diagonal or vertical cracks.
- **Deficiencies:** poor workmanship, voids in joints, raked joints, weak mortar, unfilled perpends, thick joints, no bond.

#### Under lateral load

- **In-plane:** diagonal shear, sliding shear and rocking failures.
- **Out-of-plane:** overturning, mid-height bending cracks, corner separation.
- **Deficiencies:** lack of bands and ties, heavy flexible roofs not tied, large openings near corners, weak connection between walls, no cross walls, slender walls, soft mortar and poor-quality bricks.

#### Result

Brittle, sudden failure with little warning. Measures: bands, corner bars, controlled slenderness and openings, good materials and workmanship.

## Check yourself

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

1. What are gravity failure modes?
   A. Crushing or splitting, buckling of slender walls and local bearing failure
   B. Diagonal shear only
   C. Corner separation only
   D. Overturning of parapets only
   Answer: A. These are the vertical load failures. (Key point: Gravity failure)

2. Which are lateral load deficiencies?
   A. Rich mortar
   B. Lack of bands and ties, large openings near corners, weak wall connections
   C. Cross walls present
   D. Rigid diaphragm
   Answer: B. They break box action. (Key point: Lateral deficiency)

3. What does differential settlement cause?
   A. Rocking
   B. Delamination
   C. Diagonal or vertical cracks
   D. Nothing
   Answer: C. Uneven support strains the wall. (Key point: Settlement)

## Related in Concrete Technology and Masonry Structure

- [Typical damage in masonry under lateral loads](https://www.bctengineer.com/question.md?key=semester_5%2Fconcrete_technology_and_masonry_structure%3Atypical-damage-lateral-loads) — Concrete Technology and Masonry Structure, chapter 9, asked 2×
- [Design process for masonry wall under lateral loads](https://www.bctengineer.com/question.md?key=semester_5%2Fconcrete_technology_and_masonry_structure%3Adesign-wall-lateral-loading) — Concrete Technology and Masonry Structure, chapter 9
- [Elements resisting lateral loads in masonry](https://www.bctengineer.com/question.md?key=semester_5%2Fconcrete_technology_and_masonry_structure%3Alateral-load-resisting-elements) — Concrete Technology and Masonry Structure, chapter 9, asked 6×
- [Lateral load elements; stepwise [cut off]](https://www.bctengineer.com/question.md?key=semester_5%2Fconcrete_technology_and_masonry_structure%3Alateral-elements-stepwise-74c) — Concrete Technology and Masonry Structure, chapter 9
- [Lateral load effect on wall with and without opening](https://www.bctengineer.com/question.md?key=semester_5%2Fconcrete_technology_and_masonry_structure%3Alateral-load-wall-with-openings) — Concrete Technology and Masonry Structure, chapter 9
- [Masonry structure and its limitations](https://www.bctengineer.com/question.md?key=semester_5%2Fconcrete_technology_and_masonry_structure%3Amasonry-definition-limitations) — Concrete Technology and Masonry Structure, chapter 7

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- [Distribution of lateral force among masonry walls](https://www.bctengineer.com/question.md?key=semester_5%2Fdesign_of_timber_and_masonry_structures%3Alateral-load-sharing-among-piers) — Design of Timber and Masonry Structures, chapter 6
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