---
title: "Lateral load effect on wall with and without opening"
subject: "Concrete Technology and Masonry Structure"
chapter: 9
key: "semester_5/concrete_technology_and_masonry_structure:lateral-load-wall-with-openings"
source: https://www.bctengineer.com/q/semester_5/concrete_technology_and_masonry_structure/lateral-load-wall-with-openings
site: BCT Engineering
---

# Lateral load effect on wall with and without opening

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

- Asked in: 2072 Chaitra, 6 marks
- Video: [Understanding shear walls in buildings](https://www.youtube.com/watch?v=x0DH9eAR0O0) — innotutorial
- 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/lateral-load-wall-with-openings
- Whole chapter: https://www.bctengineer.com/md/semester_5/concrete_technology_and_masonry_structure/chapter-9

## Question

Explain the effect of lateral loads on masonry wall with and without opening in wall.

## Short answer

A solid wall resists lateral load as a monolith, failing with a single diagonal crack. Openings break the wall into piers and spandrels, drastically reducing stiffness and causing stress concentrations and diagonal cracks from corners; short piers fail in shear, slender ones rock. IS 4326 limits opening lengths and requires bands.

## Answer

#### Wall without opening

A solid wall acts as a monolithic shear wall (in-plane) or plate (out-of-plane). The lateral force is carried by one wide section, so the stiffness and strength are high. Typical failure: a single large diagonal crack, or sliding or rocking at the base. The capacity is calculated on the full length $L$: $V = f_s\,L\,t$.

#### Wall with openings

Doors and windows break the wall into **piers** (vertical strips between openings) and **spandrels** (horizontal strips above and below the openings).

- Stiffness and strength fall sharply; the lateral force is shared among the piers in proportion to their stiffness (stiffness $\propto$ $t$ and falls with $(h/L)^3$ for slender piers).
- Stress concentrations at the corners of openings cause **diagonal cracks** radiating from the corners.
- Short, stocky piers fail in **shear**; slender piers fail by **rocking** (flexure); spandrels crack in shear and flexure.
- Out-of-plane: the section is weaker at the opening, cracks run from the corners of the opening to the edge, and the wall can fail at lintel or sill level.

```text
 No opening          With opening
 +---------+         +----+-----+----+
 |  \   /  |         | pier|open| pier|
 |   \ /   |   ->    | /   |    |  \  |
 +---------+         +----+-----+----+
  single X-crack      cracks from the corners
```

Hence IS 4326 limits the total length of openings (not more than 50 percent of the wall length for one storey, 42 percent for two storeys and 33 percent for three storeys), sets a minimum distance of an opening from an inside corner and a minimum width of the pier between openings (the values depend on the building category), and requires **lintel bands** and sill bands, or reinforcement around openings.

## Check yourself

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

1. What do openings do to a wall?
   A. Break it into piers and spandrels, reducing stiffness and strength sharply
   B. Increase stiffness
   C. Create a single shear wall
   D. No effect
   Answer: A. Force is shared among piers by stiffness. (Key point: Piers and spandrels)

2. How do stocky versus slender piers fail?
   A. Stocky in rocking, slender in shear
   B. Stocky piers in shear, slender in rocking (flexure)
   C. Both in crushing
   D. Both slide
   Answer: B. Aspect ratio governs the mode. (Key point: Pier failure)

3. Where do diagonal cracks start?
   A. At mid-wall
   B. At foundation
   C. At corners of openings, due to stress concentration
   D. At roof centre
   Answer: C. Corners concentrate stress. (Key point: Crack origin)

4. What is the maximum total opening length for a single storey wall?
   A. 33 percent
   B. 25 percent
   C. 75 percent
   D. 50 percent of wall length
   Answer: D. 42 percent for two and 33 percent for three storeys. (Key point: IS 4326 limit)

## Related in Concrete Technology and Masonry Structure

- [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×
- [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×
- [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
- [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
- [Diagonal shear test of masonry wall](https://www.bctengineer.com/question.md?key=semester_5%2Fconcrete_technology_and_masonry_structure%3Adiagonal-shear-test) — Concrete Technology and Masonry Structure, chapter 10, asked 6×

## Related in other subjects

- [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
- [Wall with openings: pier loads and check](https://www.bctengineer.com/question.md?key=semester_5%2Fdesign_of_timber_and_masonry_structures%3Amasonry-wall-with-openings-piers) — Design of Timber and Masonry Structures, chapter 5
- [Out-of-plane bending of a masonry wall](https://www.bctengineer.com/question.md?key=semester_5%2Fdesign_of_timber_and_masonry_structures%3Aout-of-plane-wall-flexure-check) — Design of Timber and Masonry Structures, chapter 6
- [Check of a solid brick wall under gravity load](https://www.bctengineer.com/question.md?key=semester_5%2Fdesign_of_timber_and_masonry_structures%3Asolid-masonry-wall-gravity-check) — Design of Timber and Masonry Structures, chapter 5