Section 3/4 Flashcards
3 aspects of defensible space design
Territory - creating distinction between public & private space through site design.
Access - controlling physical access through design or signage or symbolic barriers
Surveillance - seeing and being seen. Visual site lines, lighting, and increased activity.
Elements of Urbanism
Neighborhood
District
Corridor
Roadway Level of Service (LOS) ‘A’
a road with high turnover but wide street widths and comfortable for any level of driver/vehicle to handle
Roadway Level of Service (LOS) ‘D’
A road with LOS D is a road that has less travel because it is uncomfortable for higher use. It has narrow widths and is better suited in an Urban location.
ADA walking path requirements (no rails)
max slope = 1:20 or 5%
resting spots needed every 200’ that are 60” long
Types of Cut & Fill calculation methods
Average end area method
grid method
contour method
stair & landing design standards
When a stairway is required, they should be designed so that there are never less than three steps, with landings occurring after no more than five feet of vertical change, and avoiding narrow walkways, especially outdoors and at a public building.
standards for an intersection of 2 local roads
site triangle of at least 50’
a slope of 3% or less at the intersection
an offset of at least 100’ when the roads do not line up
maintaining an intersection at a right angle
Ideal Function Diagram
utilized before a site plan is created in order to work through which spaces will function well next to each other. This type of diagram only deals with connections, and does not include scale or site features.
definition of Phytoexraction
Phytoexraction is a form of phytoremediation that uses the plants natural ability to absorb contaminants and store them as part of their natural metabolism. Certain plants are used for certain chemicals. Over time, the plants are harvested and burned or recycled to further remove the chemicals from the land.
definition of phytodegradation
Phytodegradation uses plants that naturally break down the chemicals they absorb and therefore do
not need to be harvested.
definition of bioremediation
Bioremediation uses the micro flora and fauna that are present on the site already and breaking down the contaminants. The organisms are identified and the site conditions where they were found are replicated throughout the site.
definition of phytovolatization
Phytovolatization refers to the process of a plant absorbing a chemical that is present in the water and through the plant’s natural processes; the chemical is broken down and released into the atmosphere through transpiration.
definition of rain garden
type of bioretention basin used to collect water from a storm, remove some of the pollutants from the water, and then drain fairly quickly. They allow more water to enter into the ground and do so using native plants and drain quickly because of this. If the water were to stay for long periods of time, then only specialized plants could be used that can handle their roots being submerged in water. The ponding depth is usually maxed out at 6” in order to allow the water to drain quickly enough, and to limit the amount of insects that breed in the water. Finally it is better to have multiple small gardens over one big one.
Min Distance between consecutive intersections
125’ is the min. distance between intersection for safety reasons.
Military Crest of a hill
A point just down the hill of the actual crest of the hill so you don’t expose yourself against the horizon. i.e. you have more hill behind you.
Framework Plan
A planning tool or document that can coordinate future growth, development and investment within a given community. Takes a variety of considerations into account, including land use, open space, transportation / circulation, architecture, and sustainability.
Goal of ‘program refinement’
provide clear direction and vision as the project evolves
Minimum Cross-Slope for a Bike Path
2% is considered the minimum cross-slope to provide proper drainage
core principles of erosion control
Controlling runoff, minimizing disturbance, collecting sediment, and monitoring construction.
Primary purpose of historic preservation
To ensure that development does not have an adverse effect on historic properties or resources.
Although these policies protect historic structures, they do not ‘guarantee’ that they will exist in perpetuity, nor do they necessarily ensure that future generations will have access to these resources.
Benefits of Low Impact Development (LID)
sediment control, including a reduction in stormwater volume and velocity (achieved primarily through infiltration)
an increase in pervious surface
LID techniques do not result in increased sediment deposition or aggradation (build up or accumulation) in local waterways (they reduce it), nor would they be able to remove previous sediment loads.
benefits of urban infill development
- Decreased traffic congestion 2. Efficient use of existing infrastructure and services 3. Revitalization of the urban core 4. Location proximate to employment and other services
benefits of water bodies on site in temperate climate
- Bodies of water can act as heat sinks in the winter 2. They can offer a scenic quality to a project 3. During warmer months, the water could create a temperate differential that would cool the site.
concept plan level of detail
a concept plan will show more detail on a small site over a large one. For example, on a small residence you may show general locations of say a children’s pool, while on a 400 acre project that kind of detail would be irrelevant.
drainage of sports fields
2% is considered the minimum cross-slope to shed water and have proper drainage
definition of chicane
Used in slowing down traffic, it is an artificial narrowing of the roadway or can also be a turn that makes you slow down to maneuver it (like those little round-abouts in the middle of the street without any connecting streets)
Treatment Train
The path stormwater will take though the various components of collection systems will start with a green roof, then move through or over permeable pavement to a bioretention basin with underdrain before being stored in a harvest and re-use cistern.
proper orientation of a baseball field
Should be oriented in an northeastern direction to keep the sun out of the batters eyes during a game.
orientation of sports fields
Most sports fields should be laid out along a north-south axis. The exception being baseball.
Maximum distance to bldg. entrance from a parking space
It is generally agreed that site users are willing to walk a maximum of 700 feet (approximately 1/8th of a mile) to a building entrance or other localized site feature from their parking space.
National Center for a Barrier Free Environment
According to the National Center for a Barrier Free Environment, landscape architects should “Provide varying degrees of access and challenges to site users” when designing outdoor recreational facilities for the general public. The range of accessibility offers a self-selecting scale of challenge and provides for a maximum range of access.
solar panel location / orientation
Best exposure is the Southern side. However, if the Southern side is not possible (due to client restrictions or dense tree canopy, etc.) then a Western exposure would be the next best solution (most intense sun is in the afternoon).
Fundamental Principles of Sustainable Site Planning (LaGro)
- Design with Nature 2. Design with Culture 3. Design places for people.
benefits of cluster development
- it allows for open space between incompatible uses 2. displays sensitivity to the character of the site 3. preserves important existing natural functions on the site.
The Design of Pedestrian Circulation Systems should include
Separation refers to providing physical delineation between pedestrian and vehicular circulation systems.
Connectivity refers to the creation of a circulation system with a minimum of walkway interruptions that follows user’s desire lines.
Accessibility allows users of all abilities to make use of the circulation system.
Amenities references the need to provide lighting, furniture and other features to make a pedestrian system attractive to users.
3 Fundamental Principles of Composition (as it relates to the design of Landscapes)
- Balance 2. Unity 3. Emphasis
Playground Fall Surfaces
The following would be considered safe according to the National Program for Playground Safety: 1. Hardwood wooded fiber 2. Sand 3. Shredded Rubber 4. Pea Gravel
ADA ramp requirements
a path with a slope greater than 5% is considered a ramp
requires handrails on both sides maximum cross slope is 2%
maximum slope of 8.33% or 1:12
maximum ramp height is 30 inches before a landing is required
landings must be 5’ long and the width of the ramp unless there is a change in direction (5x5)
Comprehensive Plans
Community-level plans that show how a community intends to grow and develop, physically and economically, typically over a 20- to 30-year period. Comprehensive plans address several broad themes that are relevant to sustainability, including housing, transportation, utilities, natural and cultural resources, and economic development. Each theme can include specific goals for protecting cultural and natural resources and promoting sustainable and affordable development.
vehicle drop off design
sited outside of main traffic flow
oriented toward the passenger side
sites with predictable routines that experience elevated levels of criminal activity
schools
Transit Oriented Development (TOD) benefits
increase pedestrian traffic
improved economic efficiency
reduced traffic congestion
characteristics of program development
considers project budget
non linear process
anticipate future needs
predict desired outcomes
definition of exurban area
an area outside the typically denser inner suburban area, at the edge of a metropolitan area, which has some economic and commuting connection to the metro area, low housing density, and growth
ineffective lighting types
underlighting and glare
which soil type is most subject to erosion
silt
TOD principle states that developments should be within ____ miles of a transit hub
no more than 1/4 mile away
downtown locations should be 1/8 mile away
historic sites identified according to 4 criteria
- associated with events in history
- associated with the life of someone in history
- embody distinctive characteristics of type, period, method of construction, artistic value
- yields information important to prehistory or history
typical setback distance of a wetland
100 feet
typical setback for active recreation
30 foot clear zone from sports fields / courts from development. pedestrian, and vehicular circulation
guardrail required when retaining wall 30” or greater is within ___ feet of the area of travel
3
minimum width of one-way vehicle circulation
11 feet wide
minimum inside turning radius for car circulation
18 foot radius
minimum inside turning radius of large vehicles in circulation
30’ radius
parallel parking stall dimensions
9’ x 22’
parking lot slopes cannot exceed
5%
bus loading space dimensions
12’ x 45’
ADA parking requirements
1 stall for every 25 regular stalls, up to a 100 stall lot
min. 8’x20’
5’ aisle adjacent to the space (11’ wide for van stalls)
located at the shortest distance to an accessible entrance
ADA requirements for accessible entrances
at least 50% of public entrances ADA
3’ min. width
door threshold 1/2” max height
ADA standards for curb ramps
must be provided wherever an accessible route meets a curb
maximum slope: 1:12 (same as a ramp)(BUT NO HANDRAILS)
maximum slope of adjoining gutters not to exceed 5%
minimum width: 3’, not including flared sides
max. slope of flare: 1:10
sight triangle requirements
max height of shrub inside triangle is 2’
no trees allowed
sound barriers are designed according to:
mass, height (6’ min), distance from source (closer is better), length, and continuity
The most environmentally sound development is one that____?
Disturbs as little of the existing site as possible.
Adaptive reuse of existing buildings or redevelopment of disturbed areas requires minimal disruption of natural systems and should be encouraged.
The best waited minimize transportation needs for a proposed development
Select a site which is located within or adjacent to residential shopping or work opportunities
Provide a mix of uses on site to meet the needs of residents or employees
What temperature range is the human comfort zone
68 to 80 Fahrenheit, or 20 to 27 Celsius Celsius
What humidity range do humans feel most comfortable in ?
80% to 20%
What orientation should be favored for positioning structures in northern latitudes?
Southern slopes SSE to SSW
Site layout for hot arid regions should do what
Aim to balance temperature extremes by storing energy, increasing humidity, and diverting desiccating winds.
Favor Eastern slopes To avoid harsh sun and to receive cool diurnal air drainage for the upper slope
Site layout for temperate regions should do what
Seek to promote shade and evaporative cooling in warm periods, and block winds and promote heat gain in cool periods, without disrupting favorable summer wind patterns
Favor the Southeast military crest to receive of sun and breeze freeze, but to avoid cold winds at the true crest
Type planning/layout for cold regions should include
Ways to control Winter winds, and promote solar gain and storage
Favor the South to Southwestern lower slope to receive solar radiation and be protected from Winter winds, but high enough to avoid cold air drainage from upper slope
Is site layout for hot humid regions should do what
Increase shade, cooling from evaporation, and breeze
Favor the top of the Eastern slope to avoid harsh West sun and to receive the evaporative cooling effect of winds due to turbulence at the hilltop
Bioclimate Design strategies for hot arid regions
moisture conserving planting
Prevent heat build-up on structure
deflect hot winds with walls screens And earthwork
trap cool air for convection
Use walls to create micro climate courts
Use shade structures on South and Southwest walls
Use a large overhang calculated for Winter sun
avoid large exposed glass
avoid heat absorbing materials
Position the structure to benefit from diurnal air currents
Bioclimate design strategies for hot humid regions
Maximize breezes and evaporative cooling with high canopy trees and loose open planted patterns
Avoid blocking winds with tall solid walls
Seek high ground or slopes facing prevailing winds
Avoid topographical depressions
Use large overhangs calculated for severe sun angles to the East and West
Avoid excessive Earth mountain which might trap moist stagnant air
Bio climate design strategies for temperate and cold regions
Promote solar gain in Winter season
Seek Southern slopes South Southeast to Southwest
Block windchill with mixed deciduous and coniferous plants
Provide afternoon shade with deciduous trees
Divert severe northeast or Northwest Winter winds
Grade and plant for cold air drainage around structure
Avoid northern entrances both for the site and architecture
What is a shelter belt
An effective means of controlling air flow.. The longest wind shadow is produced by a shelterbelt density of 50% to 65% mass to void ratio. This translates as decidous and coniferous plantings or vertically slatted fencing.
Benefits of Earth sheltering strategies
In cold, temperate, and hot arid climates, temperature stabilization is promoted with Earth sheltering construction techniques.
Takes advantage of the constant Earth temperature the temperature to warm or cool
Wet soils should be avoided or with proper mitigation
Graduated difficulty of access concept
The objective is to provide a wide variety of trail types with a range of opportunities and experiences to accommodate or challenge all abilities
Common landslide causes
Geologic - weak materials, faults, contrasting materials
Morphological - tectonic, volcanic, glacial, erosion, vegetation removal
Climatic - rapid rain or melt, freeze and thaw, shrink and swell
Human - excavation, reservoir depletion, irrigation, deforestation
Subsidence definition and causes
Downward vertical movement of the earth’s surface, resulting from surface or subsurface causes.
Surface or internal loading Removal of subsurface material Permafrost melt Hydrocompactive soils Organic soils
Ways to reduce hazards and losses from subsidence
Avoid development in the area with Zoning and land use controls
Mitigation strategies are possible depending on the cause, size, and type of development
Results of expansive soils on structures
Creates differential movement under structures. Desiccation and wetting occurs around the perimeter of the structures. Causes downward warping, cupping, asymmetrical soil patterns (with point source moisture)
Loss prevention and reduction methods from expansive soils
Isolate structures (Replace soils, waterproof membrane, piers) Floating slabs (clear space beneath) Treatment (compaction, preventing, chemical drying) Diverting water from the perimeter of structure Avoid root zone of trees (causes desiccation)
Lowest level of lighting available
3.4 watts
Residential
Characteristics of effective sound barriers
Mass
Continuity
Height
Distance from source
Important features of sound barrier
Acoustic affectiveness
Visual interest
Cost
objectives of historic landscape site planning
○ preservation
■ protect/stabilize site features
○ rehabilitation
■ repair/alter property to be compatible for another use and preserve
features of historic/cultural significance
○ restoration
■ accurately depict historic property by reconstruction of missing features or
removal of later features
○ reconstruction
■ new construction of non-surviving landscapes/objects
When is an archeological analysis required
If a site is privately owned, unless there is specific legislature stating otherwise, any historic elements found during site excavation can be ignored.
If the site is even partially owned by the government, then the Historic Preservation Act states that a phase 1 archaeological analysis with test pits must be performed. If anything is found then a Phase 2 dig is required. A phase 3 dig is a full-blown excavation.
Cluster developments
allow for open space between incompatible uses
preserve important existing natural functions on the site
display sensitivity to the character of the site
What makes safe public spaces?
○ Clear demarcation of public vs private
○ Diversity of use
○ High level of pedestrian use
○ Natural surveillability and defensible space
○ Sense of ownership; awareness of community members
○ Good maintenance
○ Clear wayfinding
How to encourage multidisciplinary design
● diagramming the design process
● integrating input of other team members
● determining performance targets
● developing project goals
● accounting for additional time in the project schedule
● encouraging exploration
● creating feedback loops at each design phase
Playground design considerations
○ should have special areas for different age groups and activities
○ provide both shade and sun, places for quiet activity and the play facility
○ maximize visibility in and around the playground so children/parents can maintain visual contact at all times
○ provide seating in a variety of locations around the play area for small children
○ playground shouldn’t have direct street access, locate several hundred feet from the street
○ limit access, but avoid institutional feeling
○ locate group equipment near facility entrance to contribute to security
○ older kids require more turf area and larger surfaces areas
Minimum is spacing between playground equipment
12 ft
6 ft clear fall zone around each structure
acceptable fall surfacing materials (from National Program for Playground Safety):
■ shredded rubber ■ engineered wood fiber ■ wood chips ■ pea gravel ■ sand ■ PIP rubber ■ mats ■ synthetic/rubber tiles
critical height
■ the maximum height of a fall from which a life threatening head injury would not be expected
■ varies from one equipment to another
Min stair width
42 inches private
60 inches public
Handrail height
30 to 34 inches
Bike way types / classes
Class 1 - Bicycle path (Class 1)
■ Separation between bikes and road, either within ROW or outside a ROW
■ 8-12
pullouts/rest areas every 2-3 miles
■ if multi-use, install every 1 mile
■ grades don’t really exceed 3%
■ max. 4-5%
■ provide seating at top of steep trail sections
■ provide wider path on steep sections to allow passing when
people are walking their bikes
■ popular because flat grades, so many can enjoy
Class 2 - Bicycle lane (Class 2)
■ Striped, signed, and pavement markings for preferential/exclusive bike use
■ 5-6’
Or Wide outside lane: Right-most traffic lanes (14’ min.) to allow bike/car to share the same lane
Class 3 - Shared roadway (Class 3)
■ Sharrows, signage
■ Shaded with pedestrians/cars
Difference between sales and ditches
Swells arshallow, have a parabolic cross-section, and are very wide, while ditches are deeper and have a narrower geometric configuration configuration.
Transit oriented development adhere to what principles?
Mixed use
Increased for area ratio
1/8 mile from transit hub
Emphasize density over pervious
Reasons to get community input in design process
Makes Planning go smoother
Consensus
More successful outcome
Site selection considers what criteria?
Slope Adjacent uses & transit Location Soils Vegetation Hydrology Previous site uses (existing utilities or Potential contamination) Sensitive ecological areas Policy constraints
How is unity achieved in design?
Through repetition and simplicity
Grid method
Used for estimation of excavation of buildings, easy to use, rough estimate
Average end-area method
Estimates volumes on linear elements, such as roads. Takes cross sections of the road at intervals, Estimates the volume and multiplies by the distance between them.
Contour method
Very accurate for final grading and construction cost estimation. Uses a tabulation form to determine Striped area, related area, topsoil vs subsoil,etc.
How to control water pollution from nonpoint sources
Control sediment, the largest contributor of pollutants into water bodies.. Contaminants include nutrient loading, heavy metals, chemicals and pathogens.
3 types of storm water management systems
- Minor system. Also called convenience system. Includes storm sewers and road side swales, designed for 2 to 10 year storms.
- Major system. Designed for infrequent storms when minor systems are overwhelmed. Includes storm ponds and spillways for 100 year rainfall or greater.
- Water quality protection system. Traps sediment, filters and infiltrates run off to remove contaminants.Design using small storm hydrology methods.
Time of concentration
The time water takes to flow from the most distant point in a watershed to its outlet
Rational method
Way to estimate peak discharges of runoff rainfall in urban areas. one of the most widely used and accepted methods of computing runoff
Potential conflicts occurring at intersections with bicycles
Bicyclists turning left across traffic
Bicyclists crossing an intersection when vehicular traffic is entering from or turning to the right
failure to yield by both bicyclists and motorists
4 classes or vehicular circulation systems
- Freeway systems. High volume, grade separated intersections
- Major arterial systems. Through traffic through urban areas. Subject to control of entrances, exits, and curb use
- Collector street systems. Traffic moves between major arterial and local streets. Traffic controlled with stop signs on side streets
- Local street systems. Local traffic between properties
Superelevation
Cross slope of a road from the outside to inside edge measured in meters vertically per meters horizontally. Counteracts centrifugal force of a curve. Depends in climate, terrain, setting, frequency and speed of vehicles.
Average eye level of people sitting and drivers
3 ft 9 in
Elevation relief map
Determines change between highest and lowest points
Littoral zone
Area between water and high water mark
Lumen
A quantitative unit of measurement referring to the total amount of light energy emitted by a light source without regard to the direction of its distribution
Footcandles
1 fc = 1 lumen/sf
Lux
Lx = 1 lumen/1 m squared
5 topics of LEED
Impact on site and location Water savings Energy efficiency Materials selection Indoor environmental quality
Goals of a framework plan
To provide a coordinated vision of long term future growth, development, investments. Addresses high level planning. Not detailed, doesn’t address policies.
Infrastructure
Sustainability
Economy
Goals of an urban plan
Revitalize parts of a city Focus on public realm Involves the community Short term planning Graphic and maps more than text Implementation plan included
