Ground Improvement Techniques MCQ with answer and solution

Concept

In a well point system, many small well points are driven around the site. Ground water flows into them by gravity and is then pumped out, which lowers the water table.

Step-by-step solution

1. Lowering the water table in excavations is done by dewatering methods. 2. In the well point system, closely spaced well points (small perforated pipes) are installed around the excavation. 3. Water from the soil flows by gravity into the well points. 4. A header pipe and pump then remove the water, so the water table goes down. 5. So the answer is the well point system.

Explanation

The well point system is a common method to lower the water table, mainly in sandy and gravelly soils. Water flows toward the well points by gravity and a pump removes it. This keeps the excavation dry.

Why the other options are wrong

A: Dewatering is only the general name for removing water, not a specific method. C: Dehydration means removing water from a material. It is not used to lower the water table. D: Water suction method is not a standard named method in this context.

Shortcut

Lowering the water table for excavation in sand usually means the well point system.

Common mistake

Choosing Dewatering because it sounds general. The question asks for a specific method.