KDOT Geotechnical & Earthwork Inspection 4

Question 1

A KDOT inspector is overseeing slope grading on a fill embankment. The plan calls for a 2:1 (H:V) slope. If the embankment is 20 feet tall, what is the horizontal distance from the toe to the top edge of the slope?

Accepted Answer

40 feet

Answer

A 2:1 slope means 2 horizontal feet for every 1 vertical foot, so a 20-foot tall embankment requires 2 × 20 = 40 feet of horizontal distance.

Question 2

When using a nuclear density gauge, the inspector must follow NRC requirements including:

Accepted Answer

Carrying a dosimetry badge and following radiation safety protocols

Answer

Nuclear density gauges contain radioactive sources requiring NRC compliance including dosimetry badges and radiation safety training for all operators.

Question 3

What is the significance of the optimum moisture content range (OMC ± tolerance) specified for fill placement?

Accepted Answer

It identifies moisture levels where the required density can realistically be achieved

Answer

The OMC window identifies moisture conditions under which the soil can be compacted to the specified density; outside this range, the density target cannot be met regardless of compaction effort.

Question 4

During rock embankment placement inspection, what is the primary concern with oversize rock placement?

Accepted Answer

Large rocks can create voids that prevent proper compaction of surrounding material

Answer

Oversize rocks can bridge over each other, leaving voids that cannot be filled or compacted, leading to long-term embankment instability.

Question 5

What does a Unified Soil Classification System (USCS) symbol of 'ML' indicate?

Accepted Answer

Inorganic silt of low plasticity

Answer

In the USCS, 'M' designates silt and 'L' designates low plasticity, so ML = inorganic silt or very fine sand with low plasticity.

(KDOT) Certified Kansas Department of Transportation Inspector Practice Test

(KDOT) Certified Kansas Department of Transportation Inspector Practice Test

KDOT Geotechnical & Earthwork Inspection 4