Civil Engineering PE Basic Civil Engineering PE 5

Question 1

In a soil consolidation test, the time to reach 50% consolidation (t_50) is 10 minutes for a 1-inch thick doubly drained sample. What is the coefficient of consolidation c_v?

Accepted Answer

0.0197 in²/min

Answer

c_v = T_50·H_dr²/t_50 = 0.197×(0.5)²/10 = 0.197×0.25/10 = 0.00493 in²/min — using H_dr = 0.5 in (half of 1 in for double drainage) and T_50 = 0.197.

Question 2

Which type of prestressed concrete system applies prestress after the concrete has hardened and reached adequate strength?

Accepted Answer

Post-tensioned

Answer

In post-tensioning, steel tendons are stressed after concrete cures, typically using hydraulic jacks against anchorage devices at the member ends.

Question 3

The design flood for a major highway culvert crossing typically corresponds to which return period?

Accepted Answer

100-year

Answer

AASHTO and FHWA guidelines recommend the 100-year (1% annual chance) flood for design of major culverts and bridges on principal highways.

Question 4

In a CPM schedule, if Activity A has an Early Start (ES) of Day 5, an Early Finish (EF) of Day 12, a Late Finish (LF) of Day 15, the total float is:

Accepted Answer

3 days

Answer

Total Float = LF − EF = 15 − 12 = 3 days (or equivalently LS − ES = (15−7) − 5 = 8−5 = 3 days).

Question 5

In wastewater treatment, the Biochemical Oxygen Demand (BOD) test measures:

Accepted Answer

Oxygen required by bacteria to decompose organic matter

Answer

BOD quantifies the amount of dissolved oxygen consumed by aerobic biological organisms when decomposing organic matter in a water sample at a given temperature over a specific time period.

Civil Engineering PE Practice Test

Civil Engineering PE Practice Test

Civil Engineering PE Basic Civil Engineering PE 5