Earthquake-resistant building should have

Explanation:

Earthquake-Resistant Buildings

To ensure that buildings are resistant to earthquakes, the design principles need to focus on minimizing structural damage and preventing collapse. The behavior of columns and beams during seismic activity plays a crucial role in achieving this. Here's the detailed analysis:

Analyzing the Given Options

1. Option 1: Strong columns - strong beams

   • Having both strong columns and strong beams is not ideal, as it might lead to failure in an unpredictable manner during seismic activity.

   • Such a design does not follow the principle of controlled damage, which is crucial for earthquake resistance.

2. Option 2: Weak columns - weak beams

   • Weak columns and weak beams compromise the stability of the structure and may lead to collapse during an earthquake.

   • This option is not recommended and violates the principles of structural design for seismic resistance.

3. Option 3: Strong columns - weak beams

   • Strong columns and weak beams allow controlled damage during seismic activity, ensuring the beams fail first while the columns remain intact.

   • This design ensures that the primary structural elements (columns) sustain the integrity of the building, preventing collapse.

4. Option 4: Weak columns - strong beams

   • Weak columns with strong beams lead to column failure during an earthquake, which is highly dangerous as it can result in collapse.

   • Such a design is unsafe and is not recommended for earthquake-resistant structures.

Conclusion:

The correct option is Option 3: Strong columns - weak beams, as it ensures controlled damage during seismic activity and prevents the collapse of the building by prioritizing the integrity of the columns.