Site Analysis practice exam questions Flashcards
What is especially important in designing roads for drainage?
A Crown.
All roads should have a crown or high point in the center. this ensures positive drainage to each side.
Wastewater flows because of the differences in elevation…
Along Inverts the difference in elevation between 2 points at the bottom, or invert, of a sewer line is what causes water flow. Invert - can also be a term used to call out the bottom of drains, catch basins or manholes.
What is the maximum grade (slope) for a road?
Most roads should be kept at a grade less than 10%.
Very short roads and parking garage ramps are exceptions.
In northern climates, where snow and ice are problems, it is important to maintain gentle slopes.
a 12% grade would not be safe and could make driving difficult.
When Bentonite is present in the soil on a site, which foundation type would be most appropriate?
Grade beams and piers would be most appropriate.
The grade beams transfer the building weight to piers, which are commonly placed on bedrock. Voids under the beam allow the soil to expand without heaving the foundation.
Soil Bearing
Each soil type has a certain bearing capacity which is the load (measured in psf) from a building foundation that the soil can resist.
Of the various soil types bedrock and sedimentary rock have the highest bearing capacities.
When picking a location on a site for a building consider…
The shallowest portion of the site
as it would require the least cut and fill work to provide a level site, and drainage could easily be accomplished.
What is the maximum slope which is feasible to plant grass?
25% slope.
Grass in recreational areas should be limited to a 3% maximum slope.
Grass for landscaping can be planted on slopes up to 25%.
Slopes greater than 25% are difficult to mow and another ground cover should be used for them.
How does a retention pond manage stormwater run-off?
By holding the excess until it can discharge at a controlled rate into the storm sewer system.
What is the recommended maximum slope for a paved parking area?
5%.
Maximum slope for a parking lot is 5%.
The maximum slope of the accessible portion of the parking area is 2%.
The required minimum slope for drainage is 1.5%, though A 2% minimum slope is recommended.
What is the maximum Automobile ramp where pedestrians are allowed?
12% is the maximum where pedestrians are allowed
What is the maximum automobile ramp where pedestrians are NOT allowed?
15% slope is the maximum automobile ramp where pedestrians are NOT allowed
Runoff coefficient
The fraction of total precipitation falling on a surface that runs off the surface or is not absorbed into the ground.
What happens with run-off water when you have a large amount of hard-surface development on a site?
The amount of water held on the site would decrease. because all of the water would run off the hard surface.
What are the ranges of the run-off coefficient values?
0 = woody area’s with spongy soil
to
1.0 = a totally waterproof surface
At what wall height are reinforced concrete or masonry retaining walls needed?
When the height of the wall exceeds 4’-0”
If below 4’, it can usually be constructed of any suitable material such as stones, loose-laid blocks or preservative-treated wood.
Higher walls are subject to overturning forces and sliding and must be engineered to resist these loads.
