KDOT Geotechnical & Earthwork Inspection 2

Question 1

When inspecting embankment fill placement, what is the maximum allowable loose lift thickness for cohesive soils compacted with standard equipment per KDOT specifications?

Accepted Answer

12 inches

Answer

KDOT specifications typically allow a maximum loose lift thickness of 12 inches for cohesive soils before compaction.

Question 2

During a proctor test, the optimum moisture content is defined as the moisture at which:

Accepted Answer

The maximum dry density is achieved

Answer

Optimum moisture content is the water content at which a soil achieves its maximum dry density under a specified compaction effort.

Question 3

A soil sample has a liquid limit of 45 and a plastic limit of 20. What is the plasticity index?

Accepted Answer

25

Answer

Plasticity Index (PI) = Liquid Limit minus Plastic Limit, so PI = 45 - 20 = 25.

Question 4

Which type of soil classification would a KDOT inspector most likely require additional stabilization for before using as embankment fill?

Accepted Answer

CH (High plasticity clay)

Answer

CH soils (high plasticity clays) are expansive, unstable when wet, and typically require lime or cement stabilization before use as embankment fill.

Question 5

What is the primary purpose of moisture conditioning soil prior to compaction?

Accepted Answer

To bring the soil moisture within the specified range for achieving density requirements

Answer

Moisture conditioning adjusts soil water content to within the specified window near optimum so proper density can be achieved during compaction.

(KDOT) Certified Kansas Department of Transportation Inspector Practice Test

(KDOT) Certified Kansas Department of Transportation Inspector Practice Test

KDOT Geotechnical & Earthwork Inspection 2