HPGE - Definition of Terms Hydraulics and Principles of Geotechnical Engineering

A comprehensive set of flashcards based on Civil Engineering terms related to hydraulics and geotechnical engineering.

Specific Weight

The weight per unit volume of a liquid at standard temperature and pressure.

Soil

Material found in Earth's crust, composed of minerals, organic matter, and voids.

Specific Weight of liquid

Does not remain constant at every place.

Negative Skin Friction

Decreases the pile capacity and is caused due to relative settlement of soil.

Metacentric Height

The distance between the center of gravity of a floating body and the center of buoyancy.

Equilibrium (Stable)

When metacenter is above the center of gravity of a floating body.

Vertical Stress

Intensity of vertical stress at a depth due to a point load acting on the surface of a semi-infinite elastic soil mass.

Shear Strength of Cohesionless Soil

Proportional to the tangent of the angle of shearing resistance.

Porosity and Void Ratio (Equal to each other)

0.5 and 1.0 when the volume of voids equals the volume of solids.

Metacenter for Stable Equilibrium

Located above the center of gravity.

Molecules Attraction

Liquid molecules get attracted to each other due to cohesion.

Soil Classification (AASHTO)

Soil greater than 75 mm is classified as boulders.

Weight of Water Ratio

The ratio of the weight of water to the weight of solid particles.

Laboratory Tests

Direct Shear Test, Triaxial Shear Test, Unconfined Compression Test.

Deviator Stress

Can affect the shear stress in both vertical and horizontal planes.

Triaxial Shear Test

Acts on both X and Y axes.

Shear Strength of a Soil

Increases with increase in normal stress.

Undrained Shear Strength Device

Shear Vane is used to determine this property of soil.

Most Used Property in Soil Properties

Water Content.

Hydrodynamics

A branch of hydraulics that studies forces exerted by or on liquids in motion.

Hydraulic Jump

An abrupt rise in water surface from retarding water.

Sudden Drop in Shear Strength

Occurs during liquefaction in saturated cohesionless particles like sand.

Cohesive Soil Deposit Classification

Considered soft if unconfined compression strength is between 0 to 24 kPa.

Slope of Cut Surfaces (NSCP)

Shall be no steeper than 1 to 1.5 for safety.

Ground Water Table at Ground Level

Increases Vertical Pressure.

Bearings Capacity of Soil (Flooding Effect)

Decreases as groundwater table rises.

Foundation Conditions Affecting Bearing Capacity

Unit weight of soil, depth of footings, load imposed.

Hydraulic Gradient

Line joining water elevation in vertical open pipes.

Water Hammer

Pressure surge caused when a fluid forced to stop or change direction suddenly.

Flow Condition with Equal Particle Passage

Continuous flow.

Granular Soil Deposit (Medium)

Considered medium if blow count is between 10 - 30.

Cohesionless Soils Characteristic

Prone to settlement under vibratory load.

Atterberg Limits Sieve Number

Fraction of soil passing sieve number 40.

Water Content Ratio

The ratio of volume of water to volume of voids in soil.

Porosity Ratio

The ratio between volume of voids and the total volume of soil.

Maximum Unit Weight of Water

Occurs at 4 ℃.

Pressure Transmission Principle

Attributed to Pascal's principle.

Bernoulli's Principle

Total energy in a stream is constant without friction.

Grain Size and Sieve Number (No. 200)

Largest grain size that passes is 0.0740 mm.

Irregular Particle Path Lines

Indicates turbulent flow.

Discharge Measurement

Volume of liquid passing a cross-section.

Steady Flow Condition

Flow with constant discharge over time.

Surface Tension Value at Room Temperature

Approximately 0.075 N/m.

Floating Stability (Ship)

Stable if metacentric height is above the center of gravity.

Over Consolidated Soil

Soil whose effective overburden pressure is less than in the past.

Lowering of Water Table Effect

Causes a decrease of lateral pressure.

Weight of Water to Solid in Soil Ratio

Degree of Saturation.

Volume of Voids to Total Volume Ratio

Void Ratio.

Volume of Voids to Solids Ratio

Void Ratio.