SITE ASSESSMENT AND SITEWORK Flashcards
What is the human comfort zone?
65°F to 75°F, 30% to 60% relative humidity
The ideal orientation for a structure in the northern hemisphere
Slightly east of south
Advantage of northern light
Even intensity
Properly design center their devices and reduce the cost of air conditioning installation and operation by…
15% or more
Vertical baffles parallel to building walls are effective for…
All exposures
Vertical fins are most effective in…
East and west exposures
What do you call local variation and climate?
Microclimate
What is basic Wind speed in most areas?
70 to 80 mph… Corresponding to the pressure 13 to 17 pounds per square foot at a height of 30 feet
Wind loads increase with…
Height
Relationship of wind pressure (psf) to wind speed
Wind pressure varies as the square of the wind velocity in miles per hour
A wind velocity of 70 mph would create a wind pressure of ____. Double that and what happens?
Wind pressure of 13 psf. When velocity doubles, wind pressure quadruples…. But remember that velocity goes to almost zero at the ground
Wind velocity at 120 mph creates what wind pressure?
37 lb/SF
Wind velocity at 130 mph creates what wind pressure?
44 lb/SF
Wind velocity at 110 mph creates what wind pressure?
26 lb/SF
Wind velocity at 80 mph creates what wind pressure?
17 lb/SF
Wind velocity at 90 mph creates what wind pressure?
21 lb/SF
Wind velocity at 100 mph creates what wind pressure?
26 lb/SF
The number of BTU per hour that passes through one square foot of wall or roof when the temperature difference between inside and outside air temperature is 1°F
U-factor
A low U value indicates _____ while a high U value indicates ______.
A low U value indicates low heat gain or loss while a high U value indicates rapid heat loss or gain.
What is thermal inertia?
The ability of a material to store heat
How to enhance an effective Shoreline
Restrict development around the actual Shoreline
What do you call anybody of water flowing in a channel?
A stream… But obviously there’s other things to call this actually
In the hydrologic cycle, after water falls and the ground as precipitation it can follow three paths:
- Runoff into streams (small amount)
- Infiltration…. Soaked by ground (smaller amount)
- Transpiration (uptake by plants) and evaporation
The conventional solution to potential flooding involves constructing concrete channels… But if you want to be compatible with sustainable design philosophy you can do what two things?
- Use existing natural drainage channels
2. Use existing floodplains
What is the zone of aeration?
Where spaces between the soil grains contain both water and air
Where is the groundwater table located?
At the regular boundary between the zone of aeration in the zone of saturation… It fluctuates seasonally and roughly follows the ground surface
What is an underground permeable material through which water flows?
An aquifer
Three examples of good aquifers and three examples of bad aquifers
Limestone, sand, gravel… Clay, Shale, and igneous and metamorphic rocks
The solid material that forms the crust of the earth
Bedrock
Fine textured soft rock
Shale and slate
What happened to boulders?
They are tired because they fell off their bedrock
Name all the soils in descending order of structural ability
Bedrock, sleet/shale, boulders, decomposed rock, hardpan, gravel, coarse sand, fine sand, silt/mud, clay
What is larger than gravel? What is larger than that?
Cobblestones are larger than gravel and boulders are larger than cobblestones
How big is sand? How big is silt?
Send is .002 inches – 1/4 inch… Silt is less than .002 inches and deposited by water and makes mud
Which kind of soil testing is as old as the art of foundation design?
Soil load testing… The total test load is usually double the contemplated design load
Tell me about an auger boring and what that’s good for
A 2 or 2 1/2 inch auger fastened onto a long pipe drill down until it hits the first obstruction and brings up soil samples. It’s good up to 50 feet.
Tell me about it wash boring and what that’s good for
2-4” pipe with a smaller jet pipe through which water is forced. What’s washed up gets all mixed and that reduces the dependability… Also boulders can be mistaken for bedrock.
But it goes down 100 feet and more.
What is a core boring and tell me when it’s good for
More expensive, but more reliable. Penetrate all materials, go very deep, bring up complete cores of everything it passes. Made of diamond drill hard enough to cut through rock.
Tell me about a dry sample boring what is a good for
It takes a pipe with a little sampling pipe at the tip instead of a drill… Drive it down 5 inches, lift it out, then test it
In soils, why do you test specific gravity?
To determine void ratio
In granular soils, why do you test grain size?
To estimate permeability, frost action, compaction, and sheer strength
In soils, why do you test grain shape?
To estimate sheer strength
In cohesive soils, why do you test liquid and plastic limits?
To obtain compressibility and compaction values
In cohesive soils, why do you test water content?
To obtain compressibility and compaction values
In soils, why do you test void ratio?
To determine compressibility
In cohesive soils, why do you test unconfined compression?
To estimate sheer strength
You have to place the foundations _____ below the frost line
1ft
Stormwater that does not sleep into the ground is called
Run off
What do you call the design of drainage patterns on a site?
Surface water management
When do you get “sheet flow”?
When an expense of paved or planted areas slopes between 0.5% and 1.0%
The land adjacent to a building should be sloped away at a grade of…
At least 2%
Drainage ditches are sloped between ____ and ____
2% and 10%
Grass slopes shouldn’t slope more then…
25%
Groundcover like Ivy can be as steep as
50%
What are drainage tiles made out of?
PVC, clay tile
Differences between level, easy grades, and steep grades.
Level: slips between zero and 4%, appearing level to the eye, suitable for construction and outdoor activities of all types
Easy: slips between 4% and 10%, sumrell from most construction and activity
Steep: over 10%, more expensive for building, requiring complicated foundations and utility connections… Lending itself to split level design solution
Maximum desirable slope with grassy recreational areas
3%
Walkways adjacent to building should not exceed…
4% slope
the slope of parking areas should be limited to
5%
Streets used by vehicles should not exceed a slope of…
10%
For legibility, the smaller scale of the map, the larger the…
Contour interval
The slope of the storm drain must be…
0.3% minimum
The slope of a sanitary sewer must be between… And…
0.4% to 1.4%… Depending on pipe size
The slope of surface street drainage must be…
0.5% minimum
The slope of large paved or planted areas must be…
1% minimum
The slope of streets and paved driveway must be…
10% maximum but 17% for trucks in low gear
What are batter boards?
Steaks in the ground offset from the building line, which is marked using string or wires stretched between
How many inches of topsoil are there?
6”
Permanently cut slopes should not exceed hey slope of… While permanently field slopes should not exceed a slope of…
1 1/2 horizontal to 1 vertical… 2 to 1
How do you backfill?
Deposits in layers 6 inches to 12 inches in depth, thoroughly tamp and compact, avoid debris
What is a combined footing or cantilever footing?
Used to connect to the exterior column footing to the first interior column footing
A mat footing is also called a… How is a boat footing different?
Raft foundation… A boat footing is placed at a depth such that the weight of the soil removed from the excavation is equal to the load of the building and this little or no new load is added to the underlying soil
Where are you likely to use a combined footing for a cantilever footing?
When the column is at the edge of the property line
Where are caissons used?
Where went for soft soil is our encounter… They provide a method of constructing foundations below water level
What is a cofferdam?
A caisson at a bridge pier or similar construction in water, where the entire area is surrounded with watertight sheet piling, the water pumped out, and foundations constructed
What is sheeting made of/do?
Wood, steel, or precast concrete
Retain soil around an excavation
The downside of rakers
They interfere with the excavation process, i.e. get in the way… In that case you can use tiebacks
What is underpinning? What can you use?
Extending a foundation deeper. Use needle beams or pipe cylinders with hydraulic jacks
Three types of asphalt paving
Asphaltic concrete. Rolled while still hot, a mix of asphalt cement and aggregates mixed in a plant.
Cold laid asphalt. Same as asphaltic concrete but laid cold as liquid with aggregates.
Asphalt macadem. Base of aggregates compacted, then sprayed with asphalt emulsion or hot asphalt cement, then covered with fine aggregate, then rolled.
Advantage and disadvantage of brick paving
Slippery when wet. Durable and permanent when later and concrete slab foundation.
Stone cobbles are mainly used for…
Decorative effect
Granite setts have which shape? Advantage and disadvantage?
Rectangular or square blocks set in cement mortar.
Very durable. Very costly.
Flagstones refer to…
Send slabs of slate, bluestone, or soapstone. Installed on sand bed or mortar and concrete slab.
Name 4 methods to achieve vertical grade changes
Stone riprap. (Like a ground corbel).
Cribbing. (Like an earth baby bed).
Concrete or stone battered wall. Just a splayed wall.
Masonry or concrete retaining wall. Like a foundation without its upper.
Vegetation may observe up to __% of the light energy which falls on it.
90
Vegetation can reduced wind speed to less than __%.
10
Eight items usually included inside work.
- Demolition of existing buildings, site features, trees, etc.
- Earthwork (cut, fill, compaction)
- Foundations
- Utilities
- Paved roads and walks
- Landscaping
- Outdoor lighting
- Sore furniture
To save costs, arrange vehicle or circulation systems to ____ contours.
Follow
Another name for multi use districts… And what are they anyway?
Cumulative zoning… Allows residences in commercial loans and residential and commercial uses in industrial zones
What is the zoning envelope?
It is the imaginary space inside of which the building is allowed to be placed in any location as long as it doesn’t stick out of that envelope
Height limitations are more common in ______ zones.
Residential… Then commercial/industrial
What is FAR? Why does it exist?
Floor area ratio, the ratio of the floor area of the building to the total area of the site. To control the amount of site development and restricted the bulk of buildings… Encouraging openness, light, etc. in urban areas
A floor area ratio of 2.0 would permit how many square feet of floor space on a site of 20,000 ft.²?
40,000 ft.²
Residential units usually require __ spaces for parking
2 for large units, 1 for small units
What are zoning exceptions called? Why are they granted?
Variances…they are granted when the literal application of the zoning ordinance would cause an undue hardship on the owner of the site or proposed development
What is conditional use zoning?
If they use is permitted only by meeting specified conditions… Usually considered to be in the public interest
What do you call the rezoning of small individual lots?
Spot zoning
What is contract zoning?
When the government makes developers agree to give them something in exchange for a conditional use
What is the most common objective of incentive zoning?
Open space
