--- title: "Making brick masonry earthquake resistant" subject: "Building Technology" chapter: 11 key: "semester_6/building_technology:eq-brick-masonry" source: https://www.bctengineer.com/q/semester_6/building_technology/eq-brick-masonry site: BCT Engineering --- # Making brick masonry earthquake resistant Building Technology · Chapter 11: Earthquake protection & Retrofitting in building - Asked in: 2069 Bhadra, 8 marks - Video: [How to Build an Earthquake-Resistant House || How to Make Your Home or Building Earthquake-Proof??](https://www.youtube.com/watch?v=r3uCvzlssow) — ENG We Build The World - Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14 - Page: https://www.bctengineer.com/q/semester_6/building_technology/eq-brick-masonry - Whole chapter: https://www.bctengineer.com/md/semester_6/building_technology/chapter-11 ## Question How do you make a brick masonry building earthquake resistant? Explain with sketches various measures adopted. ## Short answer Use a simple plan, limit cross-wall spacing to 4–6 m, keep building low, use cement mortar (1:4–1:6) and bricks ≥3.5 N/mm². Provide RC plinth, lintel and roof bands, vertical steel at corners and jambs, limit openings to ≤50% wall length, ensure cross-walls, good corner bonding, light anchored roof, strong uniform foundation, and seismic gaps. ## Answer #### Principles for masonry - Use a simple, symmetrical plan and avoid long walls (keep the length between cross-walls to about 4-6 m). - Keep the building low (limit the number of storeys as per NBC 202 / IS 4326). - Use good mortar (cement-sand 1:4 to 1:6, not mud) and fill all joints; use bricks with a crushing strength of at least 3.5 N/mm^2 (class as per code). - Keep openings small and well placed (see below). #### Measures to make masonry earthquake resistant 1. **Horizontal bands:** RC plinth, lintel and roof bands tying all the walls together. 2. **Vertical reinforcement:** steel bars at corners, T-junctions and jambs of doors/windows, anchored in the foundation and the roof band. Typically one bar of 10 mm (single storey) to 12 mm (more storeys) at each corner. 3. **Openings:** total width of openings not more than 50% of the wall length in a single storey; piers between openings at least 340 mm wide; openings at least 600 mm from an inside corner (or as per the NBC 202 table). 4. **Cross walls and buttresses:** provide cross-walls within the spacing limits, and buttresses on long walls, to prevent out-of-plane failure. 5. **Good bonding at corners:** use toothing or stitching (and dowel bars) so that the walls do not separate. 6. **Light, well-anchored roof:** use light roofing and anchor trusses or rafters to the roof band; avoid heavy mud roofs and unanchored parapets, chimneys and gable ends. 7. **Strong foundation:** firm, uniform soil with a plinth band; avoid mixed foundations. 8. **Seismic gaps and separation:** for L or T plans. 9. **Quality control:** good workmanship and curing. ```text Wall elevation with bands and vertical bars |==================| roof band | | [] [] | | vertical bar at jamb |==================| lintel band | | |==================| plinth band ######## footing ``` ## Check yourself The answer's key points as multiple-choice questions, with the correct option and why. 1. What is the purpose of RC plinth, lintel and roof bands in a masonry building? A. Increase the dead weight to resist overturning B. Tie all walls together so the building acts as a box C. Replace the need for a foundation D. Make the walls waterproof Answer: B. Continuous bands tie the walls so they act together and reduce out-of-plane bending. (Key point: Horizontal bands) 2. Where is vertical steel provided in an earthquake-resistant masonry building? A. At corners, T-junctions and jambs of doors/windows, anchored in foundation and roof band B. Only at the middle of long walls C. Only in the roof slab D. Randomly in the plinth Answer: A. Vertical bars at corners, junctions and jambs are anchored into the foundation and roof band. (Key point: Vertical reinforcement) 3. What limit applies to total opening width in a single-storey masonry wall? A. Not more than 80% of the wall length B. Not more than 10% of the wall length C. Not more than 50% of the wall length D. No limit if lintel bands are used Answer: C. Openings weaken walls; total width is limited to 50% of wall length in a single storey. (Key point: Openings) 4. Why are cross-walls, buttresses and toothed corner bonding provided? A. To prevent out-of-plane failure and keep walls from acting separately B. To increase the number of openings C. To reduce the foundation depth D. To make the roof heavier Answer: A. Cross-walls and buttresses stop long walls falling outward; good corner bonding keeps walls connected. (Key point: Cross walls and bonding) ## Related in Building Technology - [Earthquake protection and resistant building principles](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Aeq-protection-principles) — Building Technology, chapter 11, asked 3× - [Retrofitting a brick masonry building](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Aretrofit-brick-masonry) — Building Technology, chapter 11 - [Earthquake protection of load bearing masonry](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Aeq-load-bearing-masonry) — Building Technology, chapter 11 - [Specifications of brick masonry work](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Abrick-masonry-specs) — Building Technology, chapter 3, asked 2× - [Types of bonds in brick masonry](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Abrick-bonds-types) — Building Technology, chapter 3 ## Related in other subjects - [Note for a technical talk on earthquake preventive measures](https://www.bctengineer.com/question.md?key=semester_5%2Fcommunication_english%3Anote-technical-talk-earthquake-preventive) — Communication English, chapter 4 - [Brick masonry infill walls in RC frames](https://www.bctengineer.com/question.md?key=semester_5%2Fconcrete_technology_and_masonry_structure%3Amasonry-infill-walls) — Concrete Technology and Masonry Structure, chapter 7, asked 3× - [Use of masonry; types of brick bond](https://www.bctengineer.com/question.md?key=semester_5%2Fconcrete_technology_and_masonry_structure%3Amasonry-uses-bond-types) — Concrete Technology and Masonry Structure, chapter 7, asked 2× - [Quantity method for load bearing brick building](https://www.bctengineer.com/question.md?key=semester_7%2Festimating_and_costing%3Aquantity-method-load-bearing-brick) — Estimating and Costing, chapter 2