D21 QUIZ OF THE DAY

Which footing is provided under an individual column?

• Combined footing
• Pad footing
• Raft footing
• Wall footing

Answer explanation

Pad or isolated footing is used under individual columns.

What is the function of a pile cap?

• To increase friction
• To anchor the pile
• To distribute load among piles
• To prevent uplift

Answer explanation

Pile cap helps to uniformly distribute loads to all piles.

Which type of foundation is suitable for structures with heavy concentrated loads on soft soil?

• Raft foundation
• Strip footing
• Pile foundation
• Pad footing

Answer explanation

Pile foundations transfer heavy loads to deep hard strata and are ideal for soft soils.

In grillage foundation, the clearance between RSJ beams should be at least:

• 5 cm
• 10 cm
• 8 cm
• 15 cm

Answer explanation

A minimum clearance of 8 cm is maintained for proper compaction of concrete.

The inverted arch foundation is commonly used in:

• Residential buildings
• Reservoirs and tanks
• Load-bearing walls
• Temporary sheds

Answer explanation

Inverted arch foundations are used in reservoirs, tanks, and bridges to resist lateral forces.

Raft foundation is recommended when:

• Load is light and soil is firm
• Columns are isolated
• Soil bearing capacity is low and load is heavy
• Foundation is on a slope

Answer explanation

Raft foundations distribute heavy loads over a large area on weak soil.

A strap footing is used when:

• The soil has very high bearing capacity
• The footing area is rectangular
• Two columns are close to property line and individual footing cannot be used
• The columns are isolated

Answer explanation

Strap footings transfer load from outer to inner columns without exceeding boundary.

Which type of pile resists loads through skin friction with surrounding soil?

• End bearing pile
• Fender pile
• Friction pile
• Anchor pile

Answer explanation

Friction piles resist load through skin friction and are ideal in deep soft soils.

Minimum recommended depth for foundation in black cotton soil is:

• 0.3 m
• 0.6 m
• 1.0 m
• 2.0 m

Answer explanation

Foundation must be deeper than crack depth. Minimum 1 m is usually adopted.

What is the main reason for failure of foundation in black cotton soil?

• Low bearing capacity
• Excessive moisture variation
• Wrong concrete mix
• Wind pressure

Answer explanation

Black cotton soil swells and shrinks due to moisture variation, leading to cracks.