Design Flashcards
(155 cards)
1
Q
Area Drain
A
structure similar to a floor drain that collects runoff from paved areas. Usually one is used for each 1,000-2,000 square feet of pavement.
2
Q
Asphalt - General Conditions
A
Under general conditions, properly constructed asphalt pavement requires surface maintenance or resurfacing every 20 years under typical operating conditions.
3
Q
Asphalt - Adhering a New Coat to an existing Asphalt surface
A
A bituminous binder would be used to adhere a new coat of asphalt to an existing asphalt surface.
4
Q
Asphalt - Asphalt Treated Base
A
Asphalt treated base is an alternative to untreated base material and is typically used during construction in wet or freezing conditions.
ATB acts as a water-resistant barrier that prevents the infiltration of fines into the subgrade, which occurs when water accumulates in the subgrade. Not only does this clog the base layer (thereby impeding drainage), it can also create voids in the subgrade into which the pavement may settle.
It should also be noted that ATB is about three times as strong as an untreated granular base (such as crushed rock). Therefore, it is possible to use thinner layers for the same structural support, which can save on excavation costs.
5
Q
Architectural Grid System
A
An architectural grid system utilizes the proposed building grid (established by the architect) to organize and lay out elements of the proposed site construction. It can be used to locate specific site elements on a Site Layout Plan.
6
Q
Albedo
A
Reflection of light off of a surface like Asphalt or Concrete. A perfect reflector would have an albedo of 1, whereas a perfect absorber would have an albedo of 0.
7
Q
ADA, Handrails
A
ADA-compliant handrails are required to be anywhere from 34”-38” in height.
Clear of obstructions on top and sides by a min. of 1.5”.
Handrail itself is 1 1/4”-2” in diameter if circular or to provide an equivalent gripping surface
Non-circular to have a perimeter dimension of 4 inches to 6 ¼ inches, and a cross section dimension of 2 ¼ inches maximum.
It must extend 12” horizontally beyond the top and bottom of the ramp/step and return to the wall or handrail itself.
Handrail gripping surfaces to be continuous, and to be uninterrupted by newel posts, other construction elements, or obstructions.
8
Q
ADA, Table Height
A
Tables should be located anywhere between 28” - 34” to comply with current best practices. And should have 27” clearance at the bottom of the table (can be 24” for children specific tables).
9
Q
ADA - Ramps
A
Typical slope ratios range from 1:20 (5%) to 1:12 (8.3%) for pedestrian use. 1:20 or greater require a handrail if ramp is more than 6” of vertical rise (i.e. more than a curb ramp which doesn’t require handrails). Where ramps exceed 30 ft. in length, an intermediate landing (min. 60” long) is required. If the ramp changes direction, then the landing must be 60”x60” min. Per ADA the max rise for ramps from 1:12 to 1:16 must not exceed 30 in. and an intermediate landing must be provided at least every 30 ft. For slopes ranging between 1:16 and 1:20, the maximum rise cannot exceed 30 in. and a landing must be provided every 40 ft. Cross pitch must not exceed 1:50 (2%).
10
Q
ADA- Parking
A
Space minimum 8’ wide with 5’ min access aisle. 98” is the vertical clearance for van accessible space (parking garage, etc.) Cross slope no more than 1:48 (~2%). Sign should be 60” above grade (top of sidewalk if sitting on sidewalk in front of parking space).
11
Q
ADA - Accessible Routes
A
Min. 36” wide, but can be as narrow as 32” for no more than 24” along the path and those pinches in the route can happen no closer than 48” apart.
If the route is greater than 200’ long, then there must be a 60”x60” min passing space along the route. Running slope no steeper than 1:20 (5%) with cross slope no greater than 1:48 (~2%).
12
Q
ADA - Curb Ramps
A
Min. 36” wide, with 1:12 (8.3%) running slope and cross slope no greater than 1:48 (~2%). If there is a landing area at the top, then it must be at least 36” in length, then the flares at the sides are to be no steeper than 1:10 (10%). However, if there isn’t a landing at the top then the flares need to be like ramps (i.e. 1:12).
13
Q
Abbreviations - AASHTO
A
American Association of State Highway and Transportation Officials
14
Q
Abbreviations - NFPA
A
National Fire Protection Association
15
Q
Abbreviations - CSI
A
Construction Specifications Institute
16
Q
Abbreviations - ACI
A
American Concrete Institute
17
Q
Bituminous Paving
A
Asphalt is made up of bituminous material. Bitumen is the residue or by-product when the crude petroleum is refined.
18
Q
Bioretention Systems (Bioretention Swales)
A
Vegetated swales provide an alternative to curbs and gutters. The addition of plants results in an increase of friction slowing the flow of water and increased times of concentration.
19
Q
Bioretention Systems (Bioretention Cells or Rain Gardens)
A
An informal infiltration basin often with an organic layout, that has good soil drainage, is ideally located in existing low-lying areas and away from building foundations and septic systems. It should also receive full to at least partial sun to maximize evaporation. The top 18” of soil should consist of native soil amended with compost and sand both to allow good infiltration rates and provide fertile soil that will allow plants in the rain garden to thrive.
20
Q
Beam - Compressive Force and Tensile Stress
A
A beam (a horizontal member) goes through both compressive force and tensile stress due to the way a load is placed on it. When a beam is subject to compressive force, it will exhibit tensile stress once the force passes through the Neutral Axis. Think of a sponge, bend it in half and the bottom will get compressed while the top is stretching out (pulling) which is tensile stress, so it is going through both compressive force and tensile stress at the same time.
21
Q
Beam - Applied Load
A
A beam subject to an applied load along its length will exhibit a Moment (see Moment of Force).
22
Q
Conversions - Square Inches to Square Feet
A
You need to divide by 144 (it’s square so 12” x 12” = 144”)
23
Q
Catch Basin
A
A structure typically out of concrete with an opening that is 2.5’-4’, used to collect and divert surface runoff to an underground conduction system. General rule of thumb is that one catch basin may be used for each 10,000 square feet of paved surface.
24
Q
Cistern for Rainwater Harvesting Systems (Irrigation)
A
A rule of thumb is 1” of water per week is needed for irrigation systems. If you are designing a cistern to allow for a 3 week dry spell (differs based on location) you would need to store 3” of water multiplied by the total planted area of the site. If you had say 2,500 sq.ft. of planting then 2,500 * 0.25’ (3” converted) = 625 cu.ft. of water. To convert that to gallons 1 cu.ft. ~ 7.48 gal of water. So 625 * 7.48 = 4,675 gal is the minimum size cistern you would need.
25
Cistern for Rainwater Harvesting Systems (Catching Enough Rain to meet the above example)
Though a 4,675 gal cistern is needed in the above example, that doesn’t mean that enough rain falls to fill that cistern prior to the 3 week dry period. Besides that, there is also an inherent inefficiency to all of these systems for water lost to evaporation, first flush of the system, etc. and this is typically assumed to be 75%-90%. So if you have a roof top that is 1,000 sq.ft. in area (doesn't matter if it is flat or sloped, you take the plan view area of the roof) and say a 75% efficiency, that means that 1,000 * 0.75 = 750 sq.ft. of water being stored at 1" depth. So this needs to be converted to cu.ft. so 750 / 12 = 62.5 cu.ft. and finally convert to gallons so 62.5 cu.ft * 7.48 = 467.5 gallons (again that is per 1" of rainwater fallen). So in order to fill the above cistern, we would need 10" of rain to fall (4,675 / 467.5 = 10").
26
Cistern for Rainwater Harvesting (Parts of the System)
The cistern itself of course, a distribution system, a filter (to get rid of large debris) and a catchment area.
27
Cordonata
The arrangement of stairs with ramps so that you have 1 step up and then a long ramped section, then another single step up, and another ramped section, etc. This is uncomfortable to walk on as the stride up the steps is constantly interrupted by the single steps and the slope is more noticeable between steps.
28
Culvert
Any structure, NOT classified as a bridge, that allows water to flow beneath a road, walk, or highway.
29
CUT AND FILL
NOTE: The below cut and fill methods are from LAGS starting on page 196. See that section for pictures/examples. Also info available at this website https://www.kublasoftware.com/how-to-calculate-cut-and-fill/
30
Cut and Fill (Average End Area Method)
This method is good for figuring out earthwork in construction of linear objects. To start, in plan view, draw a centerline through your path (walkway, driveway, road, etc.) This centerline is the peak of your path (dirt mounds up to it). Next take evenly located points along that path (station points, etc.) At those points cut a cross section and look at the section through the mound on a graph. Find the area of that section (if not given, cut into trapezoids and find the area of each one to get a rough total. Do the same for the next cross section at the next station point. Finally, figure out the fill in the area between them by adding both areas together, dividing that value by 2 (i.e. get the average, if it was 3 stations then you would add all three and divide by 3, etc.) and then multiply by the distance between sections to get cubic feet. Remember to divide that by 27 to convert to cubic yards if asked.
31
Cut and Fill (Grid Method a.k.a. "borrow pit method")
This method is good for excavations. Start by overlaying, in plan view, squares over the area of work. Then for each square calculate the depth of each corner from existing grade. Find the average of the 4 resulting depths (add all 4 depths and divide that answer by 4). Next multiply this average depth by the area of the square and this will give the Volume in cubic feet. Remember to divide that by 27 to convert to cubic yards if asked.
32
Grid Method - Quick Formula for more than 1 square
If you have to figure out the area of excavation of more than 1 square (e.g. 5 squares) you can apply the formula V = [(a+2b+3c+4d) * A]/4 to get V (volume) in cubic feet. Divide that by 27 to get cubic yards if asked. a = sum of depths of all corners common to 1 square; b = sum of depths of all corners common to two squares; c = sum of depths of all corners common to 3 squares; d = sum of depths of all corners common to 4 squares; A = area of ONE square only (NOT the entire group of squares)
33
Cut and Fill (Contour Method)
General purpose method that applies to a variety of situations. You can do both cut and fill in this method and would usually color fill in Blue and cut in Red. In plan, you calculate all of the area(s) of the cut or area(s) of fill. Then you add all the cuts together and separately add the fills together. Take these (individually) times the distance between contours and divide that by 27 to get cubic yards. You will then have a cu.yd. value for amount of fill and a separate value for amount of cut.
34
Concrete
Concrete is an outstanding material for use in the landscape and one of its primary benefits is that it is highly workable (adaptable), low maintenance costs, high durability, hard surface, and able to be used and applied to a wide variety of purposes (ex. Foundations, walls, walkways, site furnishings, etc). That said, concrete has several shortcomings, including susceptibility to cracking, low tensile strength, difficulty to color evenly and permanently, the need to install joints, prolonged curing time (~28 days) and the need for rebar and formwork. 1 cubic foot weights 150 lbs.
35
Concrete - Ingredients
The three principal ingredients in a concrete mix are water, cement and aggregate. Note that sand is sometimes added to concrete mixes, but is considered a less acceptable answer than aggregate, as aggregate is a broader and more inclusive term. Depending on the mix, aggregates added to concrete could take the form of sand, crushed stone or gravel, with the latter two ingredients being more common than sand. Although rebar is a necessary component to many forms of concrete construction, it is not always needed and would not constitute part of the actual concrete mix.
36
Concrete - Aggregate used in mix
As a general rule, aggregate used in a concrete mix should not exceed 1/3 the depth of the slab to be poured. Using the largest aggregate size possible can reduce shrinkage and cracking in concrete, however, oversized aggregate will create the opposite condition and exacerbate cracking in the concrete.
37
Concrete - Slump Test
The primary purpose of a slump test is to measure the workability of a concrete mix. The test itself measures the consistency of fresh concrete before it sets by placing a portion of the concrete mix into a slump cone, tamping the mix and removing the cone. The height of the mix is then measured, as is any slump or deformation in the shape of the concrete. Thus, the slump test not only checks the workability of freshly made concrete, but can also be used as an indicator of an improperly mixed batch of concrete.
38
Concrete - Compressive Strength
The compressive strength of concrete is determined primarily by the ratio of water to cement. Logically, this ratio is often referred to as the W/C ratio. Aggregate and rebar provide additional strength and reinforcement to concrete, but the ratio of water to cement is the primary determinant of the compressive strength of concrete.
39
Concrete - "Heat of Hydration"
A chemical process known as “Heat of Hydration”, or simply hydration, is initiated when cement is mixed with water to form concrete. Heat of hydration is an exothermic (heat-producing) reaction that occurs as cement particles expand due to the presence of water. The ratio of cement to water determines the extent of this reaction and is the primary determinant of the ultimate strength of the cured concrete.
40
Concrete - Wire Mesh
The primary purpose of welded wire mesh in a concrete slab is to reduce cracking.
41
Concrete - Control Joints
Control joints are installed to direct expected cracking (or reduce random cracking). They should be placed at regular intervals and keep the 'panel' relatively square. They should never be farther apart than 1.5x the width, so a 5' wide sidewalk would want them spaced less than 7.5' o.c. A control joint must also be placed where a sidewalk butts into a larger concrete area (usually separated by an expansion joint) at the corners (perpendicular to the expansion joint) of where the sidewalk hits the larger slab. So say a 5' sidewalk was coming into a 20' slab, there would need to be a control joint starting at either corner of that intersection and go the length of the slab (remember it runs perpendicular to the EJ).
42
Concrete - Expansion Joint
Isolation or expansion joints are used in concrete to allow lateral movement between adjacent slabs or other fixed structures/surfaces, and as such, should be constructed to the full depth of the concrete slab. Note that expansion joints should also be placed at the interface between concrete and other fixed surfaces, for example, where a horizontal concrete surface meets a structure. They also help create a smooth and safe walking surface.
43
Concrete - Doweled Joints
Doweled joints are used in slabs to reduce displacement.
44
Concrete - Metal Dowel
Metal dowels are typically added to concrete construction joints to transfer loads between individual slabs. Note that Tie Bars and Keyways can also be used to load transfer.
45
Concrete Vs. Masonry Products
Concrete has many benefits and can be used in a wide variety of landscape applications. However, there are numerous situations in which masonry products such as stone and brick prove to be more appropriate. As a general rule, masonry products have greater aesthetic variability than concrete, as well as a higher compressive strength and greater durability. Masonry products also generally exhibit better moisture resistance than concrete. That said, concrete is regarded as a less expensive and lower weight material than masonry and can be used to create a nearly endless variety of forms and structures.
46
"Compost Blanket"
Compost blankets are a 1-3” layer of compost loosely applied to disturbed soils. They prevent erosion and concentrated stormwater flows, reduce runoff, increase infiltration, promote the growth of vegetation and enhance soil stability in general. They therefore help protect against conditions that will create concentrated flows and high-velocity run-off. However, once concentrated flows or high-velocity run-off have been created by upstream conditions, compost blankets should not be used. So they are to Mitigate high-velocity run-off before it becomes high-velocity run-off.
47
Construction Details
To be as effective and clear as possible, each construction detail should contain dimensions, a scale to which the detail is drawn, orthographic linework and callouts for materials and other relevant annotations. Note that in specific circumstances, certain details may benefit from having isometric drawings that support or otherwise elucidate information contained in the orthographic drawing.
48
Compressive Force
Occurs when a physical force presses inward on an object, causing it to become compacted.
49
Detention Systems (Detention Basin)
Detention (or dry) basins, are used to control peak discharge rates, and flow is metered out of the basin until no water remains.
50
Detention Systems (Retention Basin)
Retention (or wet) pond that contains a permanent pool of water. This can be used for storm water management, pollutant removal, habitat improvement, and aesthetic enhancement.
51
Detention Systems (Rooftop Detention or Blue Roof)
Rooftop areas on low-slope roof surfaces can be utilized for detention of storm water. Usually water is ponded to a depth of no greater than 4" to keep weight down for structural load of the roof. Requires redundant drains (in case one gets clogged) and scuppers for overflow.
52
Detention Systems (Water Quality Basin)
Often included in the design of retention and detention basins, it provides an area for the settling out of sediments. A sediment basin is an example of this which slows the velocity of runoff in order to allow sediment particles to settle out. These need to be cleaned to remove this sediment once and a while.
53
Dust Control on a Construction Site
Proper dust control on a construction site will reduce the volume of sediments produced by construction activities. Although most sediment control efforts on a construction site address the presence of sediments in stormwater, dust also produces measurable amounts of sediments and should be mitigated by proper dust control. This would consist of adding a Stabilized Construction Entrance (a mountable gravel berm that helps remove mud and dirt from vehicle tires), or if not sufficient you can add a "Wash Rack" to wash sediment off a vehicle tires. Note that dust could potentially reduce soil fertility (through the loss of top soil) but this would be a minor factor compared to the types of things the LARE cares about (i.e. BMPs).
54
Fasteners - Snap Ties
Snap ties are a type of fastener used to hold formwork together while concrete is being poured and are designed to break away after the formwork is removed. Snap ties can remain inside concrete to provide additional reinforcement.
55
Fasteners - Non-stainless steel fixtures (Galvanizing)
Non-stainless steel fixtures used in exterior applications are often coated in zinc to prevent and reduce the formation of rust. Zinc coating is added to fasteners by dipping the fasteners in a vessel of molten zinc (a process referred to as hot-dip galvanizing).
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Fasteners - Machine Bolt Assembly
A machine bolt assembly is typically used for metal-to-metal connections
57
Fasteners - Anchor Bolts
Anchor bolts are used to connect structural and non-structural elements to the concrete. The connection is made by an assembling of different components such as: anchor bolts (also named fasteners), steel plates , stiffeners. E.g. attaching a bench to an existing concrete sidewalk.
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Fasteners - Lag Bolt with Expansion Shield
Lag Bolts are essentially large wood screws and an expansion shield is the plastic or metal device that gets inserted into concrete and brick to anchor the bolt in place.
59
Fall Zone for Playgrounds
The “fall zone” surrounding playground equipment should generally extend 6’ or more on all sides of the equipment in question. It should be noted that this metric applies to school-age children and that play equipment for infants and toddlers is permitted to have a smaller fall zone (3’).
60
Fertilizer (NPK values)
The ratio of Nitrogen (N), Phosphorous (P), and Potassium (K) present in fertilizer can be used to establish soil fertility. Numbers in a fertilizer (like 10-20-5 or 6-12-4) show a % of each NPK in the mix. So a 10-20-5 is 10% Nitrogen, 20% Phosphorous, and 5% Potassium blend. So if you want to apply 100 pounds of phosphorus you divide 100 by 20% (or 0.2) which means you need to apply 500 pounds of that fertilizer to reach that level of phosphorus. On the flip side, if you have a 100 pound bag of that same 10-20-5 and what to know how much Potassium you will be adding by applying it all, you would multiply the 100 pound size by the % or 100 * 0.05 = 5 pounds of Potassium. The equation would be Applied Lbs = Bag Lbs * %
61
Frost Line
the maximum depth of ground below which the soil does not freeze in winter.
62
Green Roofs
3 main types: Extensive - comprised of 2"-6" of lightweight mineral growing medium planted with drought-tolerant species, and subsisting solely on rainwater. Intensive - has deeper, more organic-rich soil and is planted with a range of plants and even trees. Weight is a big consideration with an intensive design. Modular - This system has trays that act like potted plants over layers of waterproofing, root barrier, insulation, etc. to form the complete roof coverage.
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Green Roofs Alternate… Brown Roofs
This is a green roof that is created to be a habitat for a particular species rather than just a planted roof. This can have the added features like wetland areas, small pools, logs, etc. to create a roof top habitat.
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Infiltration Basin
A area where water is contained by damming or excavating. It stores runoff while it enters the soil over a given time. More recently, these have been designed as depressions in the landscape as opposed to requiring an embankment for containment, and is known by the name RAIN GARDEN.
65
Infiltration Trench
An infiltration trench is an excavation backfilled with coarse aggregate stone that provide the volume for temporary storage of storm runoff until it can infiltrate the surrounding soil. The surface of the trench may be covered with grass having a surface inlet, or with porous material, such as sand, gravel, or stone. They are flexible systems that can easily be fit into underutilized or marginal areas of a site, and they can be easily adapted to an existing developed site. An observation well, such as a PVC pipe placed vertically in the trench, should be installed to monitor any change in infiltration rate on a periodic basis.
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Infiltration facilities -location on site (siting)
When siting an infiltration facility, the treatment structure should be located at least 2-4’ above the water table (not below it) and 100’ from wells. This prevents pollution of groundwater from any potentially contaminated water that may enter the infiltration basin. The bottom of the infiltration basin should also be set below the frost line to prevent heaving, and the infiltration facility should be located in soils with reasonably rapid infiltration rates to ensure that it functions properly.
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Interpolation (Calculation)
d/D = e/E where d = Distance from end point to actual spot where you are trying to determine; D = total distance between 2 known grid points; e = elevation change between the end point and the actual spot where you are trying to determine; E = total elevation change between the 2 known grid points. SO... in trying to find d you would take d = e x D / E. For example, 100' long line with 95.3 at one end and 97.3 at the other. To find out where 97 would sit on that line you do the following... D: distance between 97.3 and 95.3 is 100; e: 97.3-97 = 0.3; E: 97.3-95.3 = 2 SO: d: 0.3 x 100 / 2 = 15. In that case, the 97 elevation would sit 15 units away from 97.3 along the line. DO NOT FORGET that the answer to the equation d/D=e/E is just the change in elevation or the distance to the elevation. YOU STILL HAVE TO TAKE THAT 'ANSWER' and apply it to the graphic. Like in this case, we took the 15 units and measured that from the 97.3 end to find where the 97 point sat on the line. Also, this is ONLY valid if there is a constant slope between the 2 points.
68
LEED - Leadership in Energy and Environmental Design
LEED is a program developed by the US Green Building Council that measures and evaluates the sustainability and performance of structures and landscapes. It is a program that advocates for sustainable design and the implementation of "Green" infrastructure.
69
LID - Low Impact Development
LID is a concept that addresses hydrological flows via stormwater management, with the goal of protecting and preserving natural drainage patterns on a site during and after the development process. It is a program that advocates for sustainable design and the implementation of "Green" infrastructure. Potential benefits include a reduction in stormwater volume and velocity (achieved primarily through infiltration), a potential reduction in construction costs (achieved primarily by eliminating the need for subsurface piping and other conventional infrastructure) and a potential increase in green space (ex. vegetated LID planters).
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Moment of Force
A measure of its tendency to cause a body to rotate about a specific point or axis. In order for a moment to develop, the force must act upon the body in such a manner that the body would begin to twist. Imagine two people pushing on a door at the doorknob from opposite sides. If both of them are pushing with an equal force then there is a state of equilibrium. If one of them would suddenly jump back from the door, the push of the other person would no longer have any opposition and the door would swing away. The person who was still pushing on the door created a moment.
71
Mortar, Brick (or Masonry Mortar)
The ingredients of brick mortar are Sand, Cement (Portland cement which is made out of limestone), Water and Lime. It's role is to make one material stick to another and is used in laying CMU walls and such.
72
Mortar vs. Grout
Both are made from the same materials (namely Portland Cement, water, and fine aggregate like sand) but the difference is the amount of water mixed in each. Grout will have a higher water content as it is intended to flow and fill the gaps between tiles.
73
Manning's Equation
The Manning formula estimates the average velocity of a liquid flowing in a conduit that does not completely enclose the liquid, i.e., open channel flow. The conduit can be as simple as a stream, but can also be a pipe if it is not full (so the liquid is free flowing). All flow in so-called open channels is driven by gravity.
74
Nail - Deformed Shank Nail
These are nails that look like screws (or a wine cork screw) and are used to increase withdraw resistance.
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Nail - Advantages over Screws
When used to secure wood, nails are much faster to install and less expansive than screws. However, disadvantages vs. screws would be that nails offer less strength and durability than a connection made by screws and nailed connections can be difficult to disassemble.
76
Rebar
The size is determined by multiplying 1/8" (0.125) times the #. So #5 rebar is 0.125 x 5 = 0.625 in diameter. OR… you can just take the number and put it over 8. So a #5 rebar is just 5/8 (which if you divide is 0.625), #3 is 3/8, etc.
77
Retaining Grade and connection with walls
Exterior walls and their connection with the surrounding grade (as it butts up against it) needs to be looked at in relation to the type of material used. When it is wood, the wood should be kept a minimum of 8" away from the top of grade to prevent rot and other issues. When a wall (concrete or other) is placed on a flat slab, this connection is very difficult to waterproof. As a result the grade should slope away from this connection to keep all water running away. The best type of connection that allow the most flexibility would be a continuous wall where any floor was internally connected without any break in the exterior.
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Retaining Walls
A detail though a retaining wall would consist of showing the full height of the wall and footing itself. The footing should be sitting with the top at the frost line, and the rest of the footing below the frost line (to prevent cracking due to frost heave). Note, however, that flexible retaining structure foundations need not be set below the frost line if they are built on a well-drained subbase with suitable bearing capacities. Note that soil bearing capacity is one of the primary determinants in establishing the width of a retaining wall's footing.
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Retaining Walls - Key
A key is used in a retaining wall to reduce the chances of sliding.
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Retaining Walls - Dimensions
Retaining walls should be measured from the top of the wall to the bottom of the footer to understand the full extent of how much material will be required to construct the wall. Note that an aggregate subbase is not a footer and would not be a part of the dimension. So a stacked block wall without a concrete footer would be dimensioned from the top block to the bottom block and not including the aggregate.
81
Railing vs Guardrail
To meet code requirements, the railing should be 36" in height. Note that, unlike railings, guardrails are required to be 42" in height.
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Railing - 4" rule
Pickets that support the handrail or railing must be installed close enough that the space between them is no greater than 4". Not a 4" ball can't pass through a 4" opening, it must be larger for that to happen.
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Screw vs Lag Bolt
They are both a screw type fastener, however, a screw has a head that needs a screw driver to install while a lag bolt typically has a hexagonal head that needs a wrench or ratchet to install.
84
Seats (General details)
Generally users find seats most comfortable when they are set between 16"-20" in height. Note also that seats should generally have a minimum depth of 18".
85
Slope (Calculation)
The equation for slope is S = D/L where S = slope; D = the difference in elevation between the end points of a line; L = the horizontal or map distance of that line. Don't forget that S needs to be multiplied by 100 to make it a percent (e.g. 0.028 x 100 = 2.8%). As an example, a line goes from 47.81 to 44.37, what is the slope? D = 47.81 - 44.37 = 3.44; L = 120 (provided), so 3.44/120 = 0.287 x 100 = 2.87%. now if you wanted to find out where say 45 was on that line, you would be finding for L so L = D/S, and 45 - 44.37 = 0.63 and 0.63/0.0287 = 21.95. So the 45 point would be 21.95 units away from the 44.37 point.
86
Slope (Percentage vs Ratio)
Note that when expressing slope as a ratio (e.g. 4:1 or 3:1) you are listed the horizontal distance : vertical distance (H:V). However, when expressing slope as a percentage it is actually Rise (or Vertical distance) over Run (or Horizontal distance). This is done because you would divide the Rise by the Run to get your answer (x100 to make it a percent of course). Just different ways to express the same answer (e.g. 50:1 is the same as 2% slope).
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soil pH
Neutral pH is 7 while alkaline (or basic) is anything over 7 and acidic is anything below 7. Adding calcium carbonate or Lime would make it more alkaline or increase the pH. Adding sulphur and potentially peat moss (organic matter) would make it more acidic or reduce the pH. A note about Organic Matter - technically it 'buffers' the soil making it harder to change the pH.
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Soil (Particles)
Sand, silt and clay are the three soil texture classes, each is listed on a side of a standard soil texture triangle. Sand has the largest particle size at 0.05-2mm and these grains are visible to the naked eye. Silt has the next largest particle size at 0.002-0.05mm and is generally also visible to the naked eye. Clay is the smallest of all particles sizes and is classified as any particle falling below 0.002mm. Clay particles are not visible to the naked eye.
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Soil (Elasticity)
The ability of a soil to return to its original shape after being subjected to a load condition.
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Soil (Plasticy)
The ability of a soil to be deformed under pressure without breaking apart.
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Soil (Liquid Limit)
The minimum moisture content at which a soil will flow under its own weight.
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Soil (Bearing Capacity)
The measure of a soil to decrease in volume under the pressure of a given weight.
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Soil (Well Graded)
Well graded soil is that which has an even distribution of soil particle sizes where the small particles fill the voids created by the larger grains.
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Soil (Gap Graded)
Contains various particle sizes, but in which gradation between sizes is broken by the absence (a 'gap') of some particle sizes.
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Soil (Uniformly Graded)
Consists of a single range of particle size.
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Soil (Friable)
Soil that is easily broken part by hand.
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Soil (hardpan)
Soil that is densely compacted together or has to much material that makes it bind together and is almost impervious to water infiltration.
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Soil (Infiltration Rates)
Infiltration can be broadly defined as the movement of water through soil, rock or other material in the ground and, as such, infiltration rates are determined primarily by soil type.
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Soil (USDA Triangle)
Is only suitable to about 3ft in depth and usually relative to agriculture. It shows the soils make up of clay, silt, and sand particles.
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Soil - Compaction (Ways to Avoid during Construction)
One of the primary ways to avoid soil compaction is to limit the use of heavy equipment during the construction process. Use of heavy equipment should be avoided during or directly after precipitation events, as wet soils are more readily compacted. To rehabilitate compacted soils, one would generally determine if compaction is located in the surface or in the subsoil and then amend compacted soils with organic matter.
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Soil - Compaction (Ways to Address)
Compacted soils are one of many factors that can dramatically reduce the lifespan of urban street trees. Potential measures to address or otherwise mitigate soil compaction in urban areas include the use of suspended pavements (that is, pavements that do not transfer loads to subsurface planting soils), the installation of Silva Cells or other comparable systems below pavement and the use of structural soils. Underdrains may improve tree health in conditions with poor drainage but they would not directly address soil compaction.
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Soil - Proctor Test
A “Proctor test” would be used to determine the level of compaction of an aggregate base. The test operates under the principal that the dry density of a gravel, soil or other material for a given compactive effort depends on the amount of water that material contains during the process of compaction. Note that the level of compaction of a material is given as a percentage (ex. 95% Proctor Compaction).
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Soil - Geotechnical Soils Report
Depending on the scope of a project, it is generally considered a best practice to commission a Geotechnical Soils Report to determine the character of a site’s geology and soils. Such a report will generally contain specific recommendations for grading and drainage and should be taken into account when designing this portion of a project.
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Soil - Silty Soils
Considered the most erodible type of soil. BMP would be to add silt fences around it during construction to keep sediment out of waterways. Also, silt based soils could use organic matter to help them be better prepared to accept planting.
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Soil - Clayey Soils
Made of mostly clay they tend to be the worst at percolation or infiltration. Also, they will expand under cold temperatures so are considered "Expansive Soils".
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Soil - Slope Failure
The factors that would significantly contribute to slope failure include: altering subsurface drainage, altering surface drainage, increasing the grade of a slope, increasing loads on the slope, and removing vegetation.
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Soil - Angle of Repose
The steepest angle at which a sloping surface formed of a particular loose material is stable.
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Soil - Stockpiles on Site
Soil should not be stockpiled higher than 4'-0" if it is to remain viable for use on site. When done higher, it tends to compact under it's own weight reducing aeration and compromising soil structure.
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Soil - Tests (not boring holes, Maintenance quality test)
Soil tests should be conducted on a regular basis as part of broader site maintenance activities, with most sources agreeing that tests should occur on an annual or semi-annual basis. In locations with seasonal anomalies that affect soil conditions (such as the application of deicing salts in winter), test results should be obtained to determine the effect that these anomalies have on soil health. Test locations should be located throughout the site and cover a representative mix of conditions. While it is not necessary to test and retest the exact same location on a regular basis, testing locations should remain roughly consistent over time so that a long-term understanding of the site’s soil health can be acquired.
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Soil - Boring "Refusal"
When a drill can't advance any further (usually because it hits bedrock or another hard surface).
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Sports Fields (Property drainage of)
2% is considered the minimum cross-slope to shed water and have proper drainage
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Tensile Strength
Tensile strength - a term often associated with wood - is the measurement of a product’s resistance to “Forces parallel to the material’s grain or surface”. While tensile strength does measure the “Maximum force before catastrophic failure”, such a statement is not considered specific enough (i.e. it omits that such a force is parallel) to be the most correct answer to the question as stated.
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Therapy Gardens
When designing a therapy garden you should: incorporate the use of water to add a sensory experience and mitigate noise pollution, have ample seating areas, and make sure the area is enclosed to provide a restful space. Also, though site maintenance is critical to keep the site looking good, you should make sure to limit it to specific times as it can be noisy and disruptive.
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Tile Vent (for Trees)
Tile vents are used to aerate fill soil above an existing tree and are a used to maintain a tree's health in situation where construction-related grading results in the placement of fill soil above the roots of an existing tree.
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Unified Soil Classification System
This ASTM specification separates soils into different groups based on bearing capacity.
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Wood Deck - Ledger
A ledger is component of a deck and is a board that supports joists and transfers loads from the deck to the structure to which the deck is attached. It is the board that gets screwed directly to the building and then all the joists are attached to it with 'U' brackets and such.
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Wood Deck - Continuous Beam
A continuous beam refers to a beam that spans two or more posts.
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Wood Deck - Cantilevered
A portion of a beam overhanging a post.
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Wood - Types
A lumber tag or stamp will show you what type of wood the board is made of, the grade of the wood ("Select Structural" highest strength, best appearance to No. 1, No. 2, and No. 3 (lowest strength, not pretty). Range goes from best looking, highest strength and price to worst looking, lowest strength and price. There is also a fifth designation "Stud", meaning it's good for a load-bearing wall. Also noted will be the moisture content of the wood. Green means it is freshly cut and hasn't been put through any special drying process (other than just air drying) and usually has a green surface, next is Kiln dry (KD) or surface dry (SD) and there is also a SD-HT (high temp) which is done to kill pests which is required for lumber that is to be shipped. Finally there will be things like a certification mark and where is was milled listed on the tag.
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Wood - Bark Side Up Rule
Orienting lumber bark-side up, cupping or warping of the deck lumber will be limited to the center of the wood, not the edges (i.e. where adjacent pieces of lumber sit parallel to one another along their long edge). Cupping at the edges of lumber creates a trip hazard that can easily be reduced or mitigated by placing deck lumber bark-side up.
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Wood - Board Foot
A board foot is actually a measure of volume and is equal to a piece of wood that is one square foot by one inch thick... or more easily 144 cubic inches. So in the case of this wood, which is listed as a 2" x 6", you would multiply those dimensions (2x6=12) and then divide 144 by your answer or 144 / 12 = 12" or 1 foot of this 2"x6" wood is equal to 1 board foot. Just as another example, if this was a 1"x6" piece of wood you would multiply those dimensions (1x6=6) and then do 144 / 6 = 24" or 2 feet of a 1"x6" piece of wood to get 1 board foot. A little harder example is a 2"x10" board. Take the (2x10=20) so 144/20 = 7.2" of the 2x10 is 1 board foot.
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Wood - Pressure Treatment
A board foot is actually a measure of volume and is equal to a piece of wood that is one square foot by one inch thick... or more easily 144 cubic inches. So in the case of this wood, which is listed as a 2" x 6", you would multiply those dimensions (2x6=12) and then divide 144 by your answer or 144 / 12 = 12" or 1 foot of this 2"x6" wood is equal to 1 board foot. Just as another example, if this was a 1"x6" piece of wood you would multiply those dimensions (1x6=6) and then do 144 / 6 = 24" or 2 feet of a 1"x6" piece of wood to get 1 board foot. A little harder example is a 2"x10" board. Take the (2x10=20) so 144/20 = 7.2" of the 2x10 is 1 board foot.
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Wood - Nominal Sizing
Nominal sizing is a term most often associated with lumber. Nominal sized lumber, for instance, a 2x4, is measured prior to kiln drying and planing. Therefore, a nominal 2x4 (2”x4”) would have an actual dimension of 1-1/2” x 3-1/2”, with the 1/2” loss of material along each axis accounted for through shrinkage in the kiln drying process, as well as planing.
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Wythe
A continuous vertical section of masonry that is one unit in thickness
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Minimizing parking lot sites:
* Implement shared parking policies
* Impose codes and place a max number of spaces
* Located development near mass transit
* Encourage carpooling
* Downsize parking stall and lane size requirements
* Increase the number of compact spaces
* Locate parking lot under bldgs.
* Locating parking island in all areas of parking lot that will not be occupied by cars shortening the length of parking spaces and adding the saved footage to planting strip.
* Encourage runoff to planted areas
* Curb openings or no curbs to allow water flow
* Biodegradable planting reduces non-point source pollution and encourage infiltration.
* Scattering parking around site and breaking up large expanses of pavement can reduce site disturbance and grading.
* During construction, care must be taken to prevent compacting or disturbing existing soil or vegetation in these areas.
* Marking permeable paving will not reduce site disturbance, but can assist stormwater infiltration, soil health and reduction of heat island effect.
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Street and Driveways:
Narrow streets and road widths can mean less site disturbance. narrowing from 10 to 9 can reduce site disturbance and grading, lower resources use and maintenance requirements and encourage lower vehicle speed.
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Traffic calming:
o Promote narrowing streets
o Reduce width at pedestrian crossing points (less paving and more planted areas)
o Slower traffic, increase planting and pedestrian crossing can support more pedestrian activity.
o Creating shared driveways can also help reduce site disturbance around roads, parking, bldgs. And other paved areas should be limited to 10 feet from the structure to minimize site disturbance.
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Erosion control benefits and guidelines:
• Reduce the need of off-site soil (around 10%)
• Limit removal of vegetative covers
• Plan construction on dry season to reduce erosion
• Install sand or wind fences for high winds
• Permanent erosion control measurements:
o Vegetative buffers strips, silt fences, sediment traps, detention/retention ponds
• Protect existing vegetation:
o limit clearing vegetation to 40’ beyond bldg perimeter,
o limit clearing vegetation to 10’ beyond curbs, walkways and paved areas
o limit clearing vegetation 5’ beyond utility trenches
o place construction feces outside and around the drip line of all trees to remain.
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Water Conservation:
• Greywater: can be used to:
o Recover waste water from bldg. uses such as lavatories, showers, washing machines and other facilities that don’t involve human or food waste
o Use greywater collected from roofs or paved surfaces for irrigation (avoid particulate matters)
• Rainwater can be collected from roofs and paved ground surfaces, roofing materials from rainwater collection should be metal, clay or concrete based.
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CPTED GUIDELINES:
* Low level planting shall be less than 3ft (for shrubs)
* Changes in texture paving
* Well-lit illumination (avoid Glare)
* Define spaces and semi-private areas
* Sidewalk scale lighting
* 3’-6” visually permeable fencing
* Minimize number of entrances
* Provide extra conduit for growth and changes
* Include bollards, colonnades, signages, benches, water fountains, street parking, setbacks, guard houses and vehicle barriers.
* Install fixures to cast light pattern over a broad horizontal area rather than a tall vertical area.
* Avoid glare that handicap guards
* Foliage of large trees are usually 10’-15’ tall and often shrub-like trees are utilize as barriers or screens.
* Avoid blocking surveillance with planting
* Raise planters in place of parking lanes.
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RESIDENTIAL SITE PLANNING: Design guidelines:
* Storm water management shall be located on low topographic location
* Preserve existing trees when possible
* Separate from flood plains (150’)
* Redundant access provided to mayor roads and adjacent neighborhoods
* Setbacks for acoustic concern
* Common facilities centrally located
* Width of roads determined by the turning radius of emergency equipment access.
* Road entry to be aligned with streets
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Transit oriented development:
• TOD: areas shall be organized around walkability, with mixed uses concentrated within a quarter mile or a comfortable 5-10 min walk of a transit station
• TOD is classified by zones:
o Zona A- transit hub- downtown area – 1/8 mile walking distance
o Zone B- primary area – ¼ mile walking distance from transit, medium density
o Zone C- Secondary area – max 20 mins of walking( 1/2 mile)- 10-20 min walk
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Parking:
On-street parking should be encouraged whenever possible, as it is highly efficient form of parking.
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Typical traffic calming measures:
• Speed bumps and raised intersections
• Lateral chances such as chicanes, narrowing street and traffic diverters
• Traffic circles
• Small corner radii
• Gateway features
• Related streetscaping
such as street furniture, lighting and landscaping.
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Alleyways:
* Eliminate the demand for automobile access to the property from the front
* Reduce the need for curbs and cuts
* Reduces the number of parking garages
* Alternative for service access and utility easements
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RAMPS- General requirements:
* Min slope 1:20 = 5% - max slope 1:12= 8.33%
* Max distance is 30’
* Ramped curb cut at crosswalks can be 1:8= 12% slope if running distance is less or equal to 3’. The flared sides of curb ramps should be 1:10= 10% if ramp protrudes into a walkway and pedestrian traffic. Is extended to cross the ramp.
* Ramp for one way shall be 36”. Two way shall be 5’ min
* Landings are required at top and bottom
* Ramps with more than 30’ require middle landing
* Landing should be at least as wide as the ramp and min 60” of clear length. Landing shall be 60”x60” min if ramp change direction
* 2% cross slope max
* One way ramp shall be 36” clear width, two way ramp shall be 60” width
* 2-4 in min ramp edge protection
* Ramp rising more than 6” requires railing
* Ramps longer than 72” require railing
* Railing requires on both sides of ramps, extend 12” on top and bottom and 1 ½” min clear space between the wall and the railing. Ht shall be 34-38 in. ends must be rounded and returned
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Environmental effects of trees:
* Trees protect viewers from glare of surfaces such as water, paving and glass
* Air filtration: large masses of plants filter and deodorize air, reduce air pollution, trap particular matters, gaseous pollutants are assimilate by the leaves
* Runoff reduction- 4-5 times more than bare grounds
* Shade provision- deciduous from summer and evergreens for winter
* Sound attenuation: combination of deciduous and evergreen is better than deciduous alone. Planting trees and shrubs on earth mounts increases the attenuating effect of a buffer belt.
* Winter belt: the amount of protection afforded is directly related to the height and density of the shelter belt.
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Sound Control Strategies:
* Buffer zones
* Noise barrier walls
* Planting dense vegetation
* Earth berms (best choice)
* Construct part of the roads below the surrounding elevation
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Play Equipment/ Play area – design guidelines:
* Play must present a challenge as part of its value
* A play area must support a range of challenges, both mentally and physically
* Must be physically accessible for every user
* Accessible routes must be 60” wide min, with 1:50 max cross slope. Slope shall be 1:20 max, otherwise will be a ramp.
* Changes in level not to exeed ¼” ( ½” if beveled)
* No direct access to the street, direct access between bldg. and outdoor area
* Fencing is mandatory
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Play Equipment/ Play area – design guidelines:
| • Surfacing:
o Turf: for sport play surfaces, unobstructed recreation areas and surfaces with mounts and slope
o Hard surfaces: not for play units. Can be dirt, concrete or asphalt, artificial grass or decomposed granite.
o Shock absorbing surfaces: (for play units)
Organic material: loose bark, pine bark mulch, shredded hardwood bark
Inorganic materials: Sand, Pea gravel
Synthetic surface: poured-in-place, safety tiles
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TSS NOTES:
• Contractor responsibilities: to execute the contract work in a safe, competent and efficient manner.
• Contract documents: drawings, specs, general requirements and agreement form
• Universal design: design which seeks to eliminate barriers while providing access and usability to the broadest range of people
• Providing an accessible route is the most important way to ensure universal access
• A system of graduated difficulty of access is most applicable to the deisgn and mgmt. of outdoor recreational facilities
ADA parking shall be no less than 100’ from bldg.
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Grid Method for estimating earth volume:
* Area to be graded is divided into squares and the corners of the squares are labeled a, b,c and d, depending on the number of squares each corner pertains to.
* Subtract corner elevation with bottom desired elevation.
* Add total per letter
* Use formula V=(a+2b+3c+4d)/4 * A
* A is the area of the squares
* Divide total V/27 = total QY
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Water quality protection:
• Pollutants: sediments, excess of nutrients, heavy metals, chemical, contaminants, pathogens, thermal pollution, etc.
o Nutrients: fertilizers with carbon, nitrogen and phosphorus
o Heavy metals: copper, lead, zinc
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Stormwater Schematic design strategies:
* Use stormwater design to slow runoff velocities. Holding runoff volumes on site reduce velocity and prevent erosion
* Use infiltration strategies to mitigate loss of pervious surfaces
* Minimize impervious surfaces
* Fit development to the terrain
* Use natural drainage system whenever possible
* Urban streams should be buffered with minimum 25ft of undisturbed forest and 50-100ft of managed vegetative area.
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Watershed boundary delineation:
* Use outlet as a starting point (low point in topography)
* Work uphill at right angles to the contours
* High points may be connected by saddles
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* Use outlet as a starting point (low point in topography)
* Work uphill at right angles to the contours
* High points may be connected by saddles
* Most people are not willing to walk distances greater than 700 ft
* Human con of vision 30 degrees vertical and 60 degrees horizontal
* 1:4 ratio is the comfortable external enclosure ratio
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Bike paths- conflicts:
* Bike turning left across traffic
* Bike crossing an intersection when vehicular traffic is entering from or turning to the right
* Failure to yield by both bike and car
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Outdoor Lighting:
* Clear optical guidance can be provided with the alignment of light fixtures positioned in consistent, recognizable and unambiguous patterns.
* A staggered layout of road and pathway lights tends to obscure rather than reinforce the direction of circulation and the location of intersections
* Subtle but recognizable distinctions can be made between mayor and minor roads paths and use areas by varying the distribution and brightness of the light and by varying the heights, spacing and color of lamps.
* Clear lighting patterns reinforce the direction of circulation
* Glare from exposed lights and under lighting are mayor safety concerns
* Security is not necessarily enhance by more lighting
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Site analysis steps:
1 - Proposal phase: preliminary design and cost estimate
| 2 - Site characterization: detail site investigation may include: geotech analysis, depth of groundwater and soil test
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Site analysis considerations and site data:
o Pedestrian walkway overhead clearance is 8’
| o Street grates to be perpendicular to travel route and ½” max opening
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Require accessible parking spaces for ADA:
```
o 1-25 1
o 26-50 2
o 50-75 3
o 76-100 4
o 101-150 5
o 151-200 6
o 201-300 7
o 301-400 8
o 401-500 9
o 500-1000 20% totla
o 1001 > 20+1 for each 100 over 1000
ADA parking w is 8’ and 11’ for van with 5’ clearance path
```
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Parking:
o Parking dimensions 9’-20’
o Industrial parking 0.5/2 per 1000 sqft
o Shopping center 4/6.5 per 1000 sqft
o Medical 4.5/10 per 1000 sqft
o Convenient store 2 per 10 ft
o Homes 2 per dwelling unit
o Hotels 1 per dwelling unit
o Office 3 per 1000 sqft
o Bowling 4 per lane
o Restaurant 0.3 per seat
o Schools 1 per teacher/staff
o Hospital 1 per 2-3 beds
o Church 1 per 4 seats
o Theaters 1 per 4 seats
o Stadiums 1 per 4 seats
o Golf course 1 per acre
o Athletic fields 1 per 3000 sqft
o Pools 1 per 30 sqft
o Beach 1 per 100 sqft
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Plants:
o Vines reduce summer heat by absorbing much of the light and deciduous vines lose their leaves in the fall, allowing winter heat gain.
o The effective distance of a wind break is up to 30 times the height of the screen with maximum protection of 5-6 ft ht
o 3 rows for evergreen and 6 rows for deciduous for windbreaks
o Windscreen shall be designed to be 60% dense
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Human Factor:
| Intimate, personal, social, public space size
Intimate: 0.5 - 1.5'
personal: 1.5' - 4 -
social: 4 -12'
public: 12' +
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Open Space Standards: ___acres for ever ___ residents
10 acres for ever 1,000 residents
