Week 6: Engineering Practice, Properties, Natural Hazards Flashcards
What does one need to have to become a professional engineer?
- Engineering degree from an accredited engineering program at a Canadian University (or possess equivalent qualifications)
- Fulfill engineering work experience required for the respective province or territory for whence you’re applying for a license.
- Pass the Professional Practice Examination (PPE - good ethics)
- Demonstrate good character.
- Language requirements (must demonstrate ability to communicate in both English and French, depending on province or territory).
What is the responsibility of the Canadian Engineering Accreditation Board?
Reviews and accredits all engineering programs in Canada.
List five examples of physical PROPERTIES of a mineral/rock body.
- bpt
- fpt
- mpt
- condensation point
- evap. point
- ductility
- malleability
- solubility
- electrical conductivity
- brittle
- magnetic
- thermal conductivity
- porosity
- permeability
- resistivity
List five examples of physical CHANGES in a mineral/rock body.
- boiling
- freezing
- melting
- condensing
- evaporating
- stretching into wire
- hammer into sheet
- dissolving
- moving electricity
- shattering
- magnetic conduction
- moves thermal energy
What are the average porosities (%) of sand, sandstone, mud, shale, chalk, and limestone?
Sand: 30-50% Sandstone: 1-5% Mud: 70-80% Shale: 5-20% Chalk: 50% Limestone: 20%
Permeability is a function of:
The speed of groundwater flow.
v = k(delta h/delta L)
Where k is the permeability coefficient, h is the hydraulic head, and L is the distance between two points of measurement.
What is ‘specific gravity’, and how is it different from ‘specific weight’?
Specific gravity: the ratio of the density of a substance to the density of a standard (water, with S.G. = 1).
Specific weight: Weight of a substance per unit volume (mass x g)/(m^3)
What is stress, and what is the equation for stress?
Force applied per unit area.
Stress (sigma) = Force / Area
N/m^2
What is strain? Linear strain?
Strain is the change in the shape or size of a rock caused by stress.
Linear strain (epsilon): change in length / original length
What is the equation for elastic stiffness? (elastic force)
Elastic force = kx
Where k = stiffness coefficient, x = displacement
What is another equation for stress that involves Young’s Modulus, E?
Stress (sigma) = E x epsilon
Recall: epsilon = linear strain
What are the three types of strength that a rock body may succumb to?
- Compressive
- Tensile
- Shear
Granite has ___ compressive strength, but ___ tensile strength.
Granite has HIGH compressive strength, but LOW tensile strength.
STIFFER material constitutes a _____ applied stress vs. strain graph and a _____ value for Young’s Modulus, E.
STIFFER material constitutes a STEEP applied stress vs. strain graph and a HIGH value for Young’s Modulus, E.
STRONGER material contains a _____ drop on the applied stress vs. strain graph than weaker material.
STRONGER material contains a HIGHER drop on the applied stress vs. strain graph than weaker material.
The applied stress vs. strain graph for a MORE DUCTILE material will contain a _____ while a LESS DUCTILE material will contain an immediate _____.
The applied stress vs. strain graph for a MORE DUCTILE material will contain a PLATEAU while a LESS DUCTILE material will contain an immediate DROP.
What is the linear equation for shear stress, tau?
T (tau) = c + (mu)(sigma)
Where c is the cohesion (y-intercept), mu is the friction coefficient, and sigma is the normal stress.
What is ‘mass wasting’?
Downslope movement of rock and soil under direct influence of gravity.
List three controls and/or triggers of mast wasting.
- Saturation of material with water (water pressure reduces frictional resistance, cohesion, and adds weight)
- Oversteepened slopes
- Loss of anchoring vegetation
- Earthquake vibration
Describe a ‘rock fall’ and the triggers associated with it.
- Extremely rapid mass movement in which rocks of any size fall through air
- Trigger: undercutting, earthquakes, frost wedging, chem. weathering
Describe a ‘rock slide’ and the triggers associated with it.
- Generally very fast and destructive onslaught of rock mass down inclined slope
- Trigger: earthquakes, rain, snow melt in spring
What was the most famous Canadian rock slide?
Frank Slide (1903)
44,000,000m^3
70 fatalities
Describe a ‘slump’ and the triggers associated with it.
- Downward sliding mass of rock or unconsolidated material as a unit a long a curved surface
- Rupture forms spoon-shaped scrap
- Block tilts backward due to rotation
- Trigger: oversteepened slopes
Describe
‘debris flow’.
- Rapid event that involves flow of soil and regolith with large amount of water
- (Lahars) composed mostly of wet volcanic materials that rush down flanks of volcanoes
Describe ‘earth flow’ and the triggers associated with it.
- Slow viscous movement on hillsides
- Trigger: Water saturates soil and regolith, materials often rich in clay and silt
Why is San Francisco very prone to earthquakes?
Settles on top of a zone with lots of sheer faults, creating large earthquakes. Specific area of California settles mostly on muds deposited into the ocean, which further amplifies the effects of the earthquake(s).
What is an earthquake?
A vibration of the Earth’s crust produced by rapid release of energy, which generate seismic waves that radiate and travel through Earth.
What is the ‘hypocentre’ and the ‘epicentre’?
Hypocentre: the ‘focus’ of the earthquake, or the area inside the crust from whence the earthquake originated.
Epicentre: the point on the surface right above the hypocentre/focus.
Describe the process of an earthquake (vibrations, rebounds, etc)
- Rocks on both sides of a fault are deformed by tectonic forces.
- Rocks bend and store elastic energy
- Rocks rupture, then perform elastic rebound.
- Rebound radiates seismic waves (like spring oscillations)
The Richter scale goes up by a factor of _____ per level.
Approx. 32 (or root 1000)
What is ‘liquefaction’?
Seismic vibrations cause saturated sand grains to separate, so the ground temp. becomes fluid.
What are some of the hazards caused by earthquakes?
- liquefaction
- differential settlement and fault offset
- mass movement / landslides
- structural damage
- tsunamis
