Ballast: Chapter 12 - Site Work Design Development Flashcards
Aboveground Drainage Systems
Pervious paving, sheet flow, gutters, ground swales, and channels
Underground Drainage Systems
perforated drains and enclosed sewers
What is the minimum drainage slope to facilitate sheet flow on a paved surface?
As little as 0.5% (6” per 100’) for smooth surfaces, but typically 1.5% (1.5’ per 100’) for rough paved surfaces
What is the minimum drainage slope for underground piping?
0.3% (4” per 100’)
Storm Drain
Collect water from roof downspouts, drain inlets, catch basins, and drain tiles surrounding the building foundation
Drain Inlet
An opening in the ground that allows stormwater to run directly into the storm sewer
Catch Basin
Underground reservoir that has a sump built in to collect and prevent debris from flowing into the storm sewer
Runoff Coefficient
The fraction of water not absorbed by the site itself
An n-year Storm
Inversely related to the probability of a storm of said value happening in a given year (100-year storm has 1% chance, 25-year storm has 4% chance)
What n-year storm are drains commonly designed for?
A 25-year storm
Holding Pond
Collects storm runoff and releases it into the sewer system at a controlled rate
Which utility usually takes precedence in planning a site and why??
Sanitary and storm sewer because because they depend on gravity flow
What is the minimum slope for a building sewer?
0.5% - 2.0% depending on the diameter. The narrower the diameter the greater the necessary slope.
2.5” dia. pipe: 0.25” per ft
3.0” - 6.0” dia. pipe: 0.125” per ft
>8.0” dia. pipe: 0.0625” per ft
Minimum width for 1 and 2 way driveways?
12’ for 1 way; 24’ for 2 way
Minimum distance between driveway entry and public intersection?
150’
Minimum radius for cul-de-sac turnaround?
40’
Suggested width for planting strip between movement lanes?
7’ with trees, 4’ with just grass
Width of side parking lane?
8’
Maximum slope of roadway?
15%, but 10% or less is preferable with transition slopes before and after the ramp of half the ramp’s slope; there should also be a level area between any slope and a sidewalk crossing for car to settle
The high point in the center of the roadway with a gradual cross slope running to a gutter or drain?
The crown
Minimum slope from crown of road to gutter or drain?
0.25” per ft
Suggested height of gutter located on a road?
6”
Minimum widths of sidewalks and main walks?
5’ and 6’ - 8’
Maximum slopes for walks?
4% (0.5” per ft) cross slope
6% preferred elsewhere
8% absolute max (1” per ft; 1:12)
Max slope and length of ADA ramp?
1” per ft (1:12) and 30’ without a landing
Required parking is determined by what document?
Zoning Ordinance
What is the standard size of a parking space (parking bay, parking stall, car stall)?
9’ x 19’ for a standard car and 7’-6” x 15’ for a compact car (400 sq.ft. per car is used to approximate total area needed for a parking lot).
What angle of parking arrange is the most space efficient?
90 degrees (double loaded)
What angle of parking is easiest to navigate?
30 degrees
Minimum width of ADA van parking space with access aisle?
16’ (8’ space with 8’ aisle or 11’ space with 5’ aisle)
In general how does a row of trees of a certain height affect the velocity of wind?
30% - 40% reduction at a distance about 5 times the height of the trees
Suggested slope in a parking area?
1.5% (18” per 100’) to 5% (5’ per 100’)
2% or 3% are most common
What are the azimuth and altitude of the sun?
Azimuth is the compass orientation of the sun and the altitude is the apparent height of the sun measured at an angle from the horizon.
What are the 4 types of sun charts?
Rectilinear, Equidistant horizon projection, Gnomonic projection (sunpeg chart), and the Stereographic (fisheye) projection
Passive Solar Energy System
Collects, stores and distributes solar energy without the use of mechanical equipment
Direct Gain Systems
Collect heat through south-facing glass and then store this heat in high-mass materials such as concrete floors, masonry walls, tile, stone, and terrazzo. During the night, these materials slowly release the heat.
To make this work efficiently, glass area must be well insulated at night or low emissivity (low-e) glass.
Indirect gain Systems
Collect heat from air temperature or reflected light. During the night, these materials slowly release the heat.
This is 1/4 as effective as Direct Gain Systems.
Thermal Storage Wall
Part of a Direct Gain System, a wall is placed opposite a south-facing glass wall.
Most are vented, which allows cool air to circulate in the space between the glass and wall, become heated, and travel by convection up and over the wall and back into the space. Thermal storage walls can also be constructed of water containers as water is more effective at storing heat.
Trombe Wall
Part of a Direct Gain System, a wall is placed opposite a south-facing glass wall.
The wall is vented on the top and bottom, which allows cool air to circulate in the space between the glass and wall, become heated, and travel by convection up and over the wall and back into the space.
Phase Change Materials
Used to avoid the overheating and wide swings in temperature in concrete, masonry, and water.
Eutectic salts that change from solid to liquid at 70 degrees F are commonly used as they store regular heat as well as latent heat as they change state.
Greenhouse Design
Features a large glazed area on the south side of the building with a high thermal mass wall separating it from the rest of the structure. A rock bed or high thermal mass floor is built in the greenhouse.
While the greenhouse overheats and is subject to thermal loss at night, the warm air circulates into the rest of the space.
Roof Pond
Stores heat in large water-filled bags on the roof of a building. In winter during the day, the bags heat up. At night, insulation is moved over the roof pond and the bags release heat down into the building.
The same system can be used inversely (insulation down during the day) to cool a space.
Active Solar Design
Uses fans, pumps, ducts, and other mechanical equipment to collect, store, and distribute solar energy.
The most common example of an Active Solar Design System is a “passive system with active assist (using an accompanying system of ducts and fans to distribute heat).
What 3 components make up an Active Solar System?
A collector, storage device, and a distribution system.
