The minimum thickness of shear walls as per IS : 13920 is

Explanation:

Minimum Thickness of Shear Walls as per IS: 13920

As per the guidelines mentioned in the Indian Standard Code IS: 13920 (Ductile Detailing of Reinforced Concrete Structures Subjected to Seismic Forces), the minimum thickness of shear walls is recommended to ensure adequate strength and stability under seismic loads.

Analyzing the Given Options

1. Option 1: 180 mm (Incorrect)

   • This thickness is too low for ensuring ductility and strength requirements in seismic zones as per IS: 13920.

   • It does not satisfy the minimum requirements laid out in the code.

2. Option 2: 400 mm (Incorrect)

   • This thickness is excessive for most practical applications and exceeds the minimum requirements.

   • While it provides adequate strength, it is not the minimum thickness as specified in the code.

3. Option 3: 200 mm (Incorrect)

   • This thickness is greater than the minimum requirement, but it is not the absolute minimum specified by the code.

   • It satisfies the ductility and strength requirements, but does not match the minimum specified value.

4. Option 4: 150 mm (Correct)

   • This thickness is the minimum specified by IS: 13920 for shear walls.

   • It ensures adequate strength and ductility while being economical for construction.

5. Option 5: Not provided (Irrelevant)

   This option is not relevant to the question or does not align with the IS: 13920 guidelines.