CC3 TERMS

Which of the following is a COMPONENT of soil, NOT a measured property or index?

Gas (air)

Manometers are primarily used to measure:

Difference in pressure at two points

A balloon filled with hot air has a lower density than the surrounding ambient air. Why does it rise?

Due to buoyancy (upward buoyant force exceeds its weight)

Regarding the water content (moisture content) of soil, which statement is correct?

It can be greater than 100%

Section 302.2.2 of the National Structural Code of the Philippines (NSCP C101-10) provides that the slope of cut surfaces shall be no steeper than:

1 to 1.5 (H:V)

The shear strength of a cohesive soil (Mohr-Coulomb: τ = c + σ tan φ):

Decreases when normal stress decreases

In a triangular channel section, the most economical section is achieved when the sloping sides make an angle of ___ with the vertical:

45°

Why do saturated clays typically exhibit lower shear strength under rapid (undrained) loading compared to drained conditions?

Excess pore water cannot drain fast enough, preventing effective stress increase

Which of the following quantities is always conserved in ideal (Eulerian) hydrodynamic flow?

mass

The largest grain size that passes a No. 200 sieve is approximately:

0.0740 mm

What is the most hydraulically efficient cross-sectional shape for an open channel, conveying maximum flow for a given area and slope?

Semi-circular

A granular soil deposit is classified as 'loose' if the blow count from a Standard Penetration Test (SPT) is between:

4 to 10 blows/ft

The undrained cohesion strength of a cohesive soil can be expressed as C = KQ (where Q is the unconfined compressive strength). The value of K is:

0.50

One of the following foundation conditions does NOT affect foundation settlement:

None of the above — all listed conditions affect settlement

Among the shear strength tests, which test measures the shear strength of a soil sample under various controlled confining pressures?

Triaxial test

A pressure surge or wave caused when a fluid in motion is forced to stop or change direction suddenly (momentum change) is referred to in hydraulics as:

Water hammer

A body placed in a liquid is buoyed up by a force equal to the weight of the displaced liquid. This principle of buoyancy was attributed to:

Archimedes

What force allows small insects to walk on the surface of water?

Surface tension

If the discharge passing a given cross-section of a stream is constant with time, the flow at that section is called:

Steady

The shear strength of a cohesionless soil is best described as:

Proportional to the tangent of the angle of shearing resistance (tan φ)

In any stream flowing steadily without friction, the total energy contained is the same at every point in its path of flow. This principle is attributed to:

Bernoulli

According to Darcy's Law, the quantity of seepage of water through soils is proportional to:

Both coefficient of permeability (k) and total hydraulic head loss (h)

The neutral stress (pore water pressure) in a soil mass is defined as:

Stress carried by the pore water (fluid phase)

What is the ratio of the volume of water to the volume of voids in a soil sample?

Degree of saturation

A ship floating in seawater is stable if the metacentric height (GM) is:

Above the center of gravity

In a cylinder containing liquid and revolving about its vertical axis, the rise of the liquid along the walls above the initial level is:

Equal to the depression of liquid at the axis

The fraction of soils passing which ASTM sieve number is used for Atterberg Limits (liquid limit, plastic limit) tests?

No. 40

process by which water-saturated cohesionless soil (e.g., loose sand) temporarily loses its shear strength and bearing capacity, behaving like a liquid due to excess pore pressure build-up, is called:

Liquefaction

What type of soil typically has the highest angle of internal friction (φ)?

Dense gravel

The component of shear strength in cohesive soils that is attributed to interparticle attraction and is independent of normal stress is called:

Cohesion (c)

According to the Unified Soil Classification System (USCS), a soil particle with a size between 75 mm and 300 mm is classified as:

Cobbles

One of the following foundation conditions does NOT directly affect the bearing capacity of the supporting soil:

Load imposed onto the soil

Which of the following is NOT a component of a soil mass?

None of the above — all listed items are valid components of soil

The fluid pressure exerted by mercury is roughly how many times greater than that exerted by water at the same depth?

13.6 times

Which of the following shear strength tests is NOT performed in the laboratory — it is a FIELD test?

Vane shear test

A line joining the points of highest elevation of water in a series of vertical open pipes rising from a pipeline in which water flows under pressure is referred to as:

Hydraulic gradient line

Water achieves its maximum unit weight (density ≈ 1000 kg/m³) at a temperature of:

4°C

What branch of hydraulics deals with the study of forces (including velocity and acceleration) exerted by or upon liquids in motion?

Hydrodynamics

A gate is inclined at 45° to the horizontal and submerged in water. The center of pressure lies:

Below the centroid of the gate area

What is the ratio of the weight of water to the weight of solids in a given volume of soil?

Water content

The volume of liquid passing a cross-section of a stream is called:

Discharge

Which of the following statements about soil compaction is INCORRECT?

Compaction does not affect the structure of soil

Among the methods for determining the shear strength of soils, which test may NOT accurately represent actual field drainage conditions?

Unconfined compression test

What is the ratio of the volume of voids to the total volume of a soil mass?

Porosity

A granular soil deposit is classified as 'medium dense' if the blow count from a Standard Penetration Test (SPT) is between:

10 to 30 blows/ft

What happens to the lateral earth pressure when the groundwater table is lowered?

Lateral earth pressure increases

If the water content of a fully saturated soil mass is 100%, the void ratio of the soil sample is:

Equal to the specific gravity of the soil solids (Gs)

Soil primarily derives its shear strength from its capacity to resist:

Shear stress along failure planes

The admixture of coarser particles like sand and silt to clay causes:

Decrease in both liquid limit (LL) and plasticity index (PI)

The pressure exerted onto a liquid is transmitted undiminished to all portions of the liquid. This principle of mechanics is attributed to:

Pascal

In the Unified Soil Classification System (USCS), fine-grained soils are classified as HIGHLY plastic (denoted by 'H') if the liquid limit (LL) is greater than:

50%

Section 302.4.5 of the National Structural Code of the Philippines (NSCP C101-10) provides that the slope of fill surfaces shall not be steeper than:

1:2 (H:V)

In a triaxial shear test, stresses are applied in which direction(s)?

All three principal axes — confining pressure on all sides plus axial deviator stress

Which test is commonly used in the Philippines (particularly by DPWH in roadworks) to determine the in-situ density of compacted soil?

Sand Cone Method (ASTM D1556)

If with steady flow in any length or reach of a stream, the average velocity at every cross-section is the same in that reach, the flow is said to be:

Uniform

A DPWH sieve analysis yields Cu = 2.8 and Cc = 4.2. How is this soil's gradation best described?

Poorly graded

When the path lines of the individual particles of a flowing liquid are irregular curves and continually cross each other forming a complicated network, the flow is called:

Turbulent

The maximum dry unit density to which any soil can be compacted (at optimum moisture content) depends upon:

Both moisture content and amount of compaction energy applied

One of the following is NOT a characteristic of cohesionless soils:

Practically impermeable

.In accordance with the Unified Soil Classification System (USCS), a soil is considered coarse-grained if the percentage of material passing the No. 200 sieve is less than:

50%

In a triaxial test, along which plane does the additional deviator stress most critically induce shear failure?

An inclined failure plane

In the AASHTO soil classification system, a soil particle whose size is greater than 75 mm is classified as:

Boulders

If the volume of voids is equal to the volume of solids in a soil sample, the porosity (n) and void ratio (e) are, respectively:

0.5 and 1.0

Which soil property generally increases with an increase in compaction effort (for granular soils)?

Angle of internal friction (φ)

A cohesive soil deposit is classified as 'soft' if its unconfined compressive strength (qu) in kPa is between:

24 to 48 kPa

Among the laboratory methods for determining shear strength of soils, which test is the simplest and least expensive?

Direct shear test

What laboratory test is commonly used to determine BOTH the cohesion (c) AND the angle of internal friction (φ) of a soil?

Direct shear test

What is the ratio of the volume of voids to the volume of solids in a soil sample?

Void ratio (e = Vv/Vs)

In an open glass tube, the meniscus (curved surface) of mercury is:

Curved upward / convex (dome-shaped)

If the depth below a liquid surface is doubled, the hydrostatic pressure will:

Double

A soil whose present effective overburden pressure is less than that which the soil experienced in the past is called:

Over-consolidated

.If the ground water table in a soil formation rises as a result of flooding, the bearing capacity of the soil will:

Decrease

Which of the following correctly lists the primary classifications of flow in fluid mechanics?

Laminar, Turbulent, Uniform

In fluid mechanics, an ideal (perfect) liquid is described as:

Frictionless and incompressible

What is the abrupt rise in water surface that results from retarding water flowing at a lower stage?

Hydraulic jump