LARE 4-2 Flashcards
Soil should be stockpiled to which max. height?
4’-0”
Accelerating admixture effects
shortens the setting time of concrete, results in higher early strength and increases dry shrinkage during setting
What is included in an invitation to bid
Project title & description, identification of principals (ie landscape architect), time and place for receipt of bids, type of contract. Does NOT include bid form.
Most erodable type of soil
fine, silty soils
Northing and easting values are associated with what layout system
coordinate system (a grid used to locate points 2 dimensionally)
Benefits of sustainable stormwater management
Reduce downstream flooding Lower site maintenance cost Improve safety Provide wildlife habitat Maintain soil moisture Create recreational opportunities
Purposes of level spreaders
distribute stormwater over a wide area
Maximize filtration by adjacent vegetation
Minimize erosion
Tile vent
aerates fill soil above an existing tree
Hooded riser
used in wet retention ponds to control discharge of water to treatment facility; it is protected from debris with wire mesh and a hood; height corresponds to maximum storage depth of the pond
Appropriate elements for a therapy garden
provide enclosure
include water
limit maintenance (it can be disruptive)
depth of subdrain pipes
below the frost line
Factors that can contribute to slope failure
increasing grade increasing load on slope removing vegetation altering surface drainage altering subsurface drainage
Purpose of stormwater detention facilities
hold runoff during storm events and release after peak storm has passed; control peak discharge (not intended to infiltrate stormwater)
Reference specifications
are developed by industry professionals and associations (reduce length of specifications by referring to preset standards)
Advantages of nails over screws in wood construction
lower materials cost
quicker installation
Advantages of concrete
high durability
low maintenance cost
hard surface
adaptability
Disadvantages of concrete
require joints
low tensile strength
difficult to color evenly and permanently
Components of a tree protection plan
location of trees Location of plants to be protected Survey base protection fencing limits of work reference notes keynote list
Stabilized construction entrance
mountable
Parts included in Project Manual
General Conditions Bidding Documents Sample Forms Schedule of Drawings Supplementary Provisions Technical Specifications
Average End Area Method
method for calculating volume of cut/fill - best for linear areas
V=(A1+A2)xL
Cut and fill are calculated separately
Extensive Greenroof
planting medium typically 1.6-6” deep
Typically use drought tolerant sedums and grasses
Typically used for sustainability or building-performance purposes (not human enjoyment)
Intensive Greenroof
Over 6” of planting medium
May include shrubs or trees
Typically used when they can be enjoyed by people
Flow sensor
installed in an irrigation mainline to detect leaks
located at the beginning of the irrigation system, after the backflow preventer and master valve; detects water flowing through mainline when system is turned off
Knox Box
Fire Access Box - allows firefighters or emergency personnel to access via a PIN; metal box that contains keys; does not require electric power or phone line
Expansion shield
used to anchor lag bolts to concrete or masonry
anchor bolt
used to attach structural elements to concrete; one end is embedded in concrete, other end is threaded to attached to structural support (also called J bolt)
carriage bolt
used to fasten wood to metal, or fasten to pieces of wood; round, dome shaped head; square neck
machine screw
have uniform diameter (no tapered end) used to fasten machine parts; may have unthreaded shoulder; hex or square head
toggle bolts
have wings that open for attaching to hollow structure like drywall
Bolts vs screw
bolts are used with a nut bolts often have unthreaded shank screws are often tapered screws must always be turned to install often bolts are held static while nut is turned to install
Lag bolt
heavy duty bolt; require pilot hole and washer; driven in with a wrench
lag bolt with fiber plug
anchor for use with wood or metal formed of braided jute fiber in a tube shape
Lag bolt with lag shield
metal anchor that expands to fill pre drilled hole in concrete or masonry when lag bolt is tightened; resistant to temperature fluctuations
threaded rod
rod with thread on both ends or fully threaded, designed to be used in tension; also known as stud
concrete nail
more heavy duty than wood nails; used to attached flooring to concrete
joist hanger
pre-manufactured metal piece used to attached joists to a ledger or beam; should be galvanized
post anchor
metal piece attached to a footing, used to secure wood post and protect it from ground moisture
post cap ties
connect 2x2’s to a 4x4 post
post tie plates
attaches boards to posts; lighter duty than post cap ties
metal strap/structural tie
used to reinforce connections between joists, ledgers, beams, posts; flat pieces of metal with holes for screws or bolts; may be straight, L or T shaped
plate anchor
used to stabilized cracking or bowed foundation or retaining walls
masonry wall tie
used to connect brick outer wall with concrete block structural wall
Rivet
smooth fastener with an end that expands 1.5 times the original diameter when using a rivet gun
z anchor
used to install natural stone slabs
geosynthetic reinforcing grid
used to increase soil strength under tension, such as under a road or behind a retaining wall
Welded wire mesh
alternative to using steel bars to reinforce concrete; saves time, labor and money
Expansion joints
full depth of concrete
must be placed between concrete and building
allows for lateral movement between slabs
Control/contraction joint
controls cracking to predetermined locations
panels should be square if possible and not exceed 1:1.5 ratio
joints commonly 24-30 times slab thickness
Min. depth 1/4 slab thickness
Must be placed at corners of pavement perpendicular to expansion joints
benefits of masonry above concrete
greater aesthetic variability greater durability higher compressive strength better moisture resistance (however it is more expensive and heavier)
Location of infiltration basins
2-4’ above the water table
100’ or more from wells
Bottom set below the frost line
in soils with reasonability rapid infiltration rates
ADA accessible table height
28-34”
Truss reinforcement
longitudinal wires connected to diagonal wires between layers of masonry wall
Fire protection planting zones
30’ from building - protection zone (low flammability, low stature plants, no wood furniture or mulches)
100’ from building - buffer zone
natural area fuel reduction zone (remove brush, prescribed burnings)
first flush
the first .5 to 1.5 inches of rainfall that accounts for 75% of pollutant discharge in stormwater
truncated hydrograph method
captures and retains the first flush on site - retains enough runoff volume to maintain predevelopment peak flow; does not control peak flow from storms larger than the design storm; eliminates natural stream flows from storms less than the design storm
Integrated water balance planning
integrates water supply, water use, water storage, water disposal into one process within a site design
water quality volume calculation
multiple square feet of impervious surface by water quality depth in feet (.083 feet = 1 inch)
determining bioretention depth/area
water quality volume divided by area or depth (to find area or depth) - depth is usually 6-12 inches
Sizing infiltration systems
basin volume = volume to be infiltrated / void space (usually 30% for gravel filled basins)
Infiltration basin depth calcuation
Max depth = (drying time in days x soil infiltration rate (in feet per day) x safety factor) / void space (usually 30%)
Porous paver design requirements
soil must have infiltration rate of .5” per hour
adjacent landscaped areas should drain away to avoid sediment clogging
infiltration times for various stormwater control measures
rain garden - infiltrate in 1 day
bioretention basin - 48 hours
Bioretention area design
contains underdrain
can remove some pollutants
max drainage area of 1 acre
locate close to source of runoff
use a flowsplitter to allow larger storms to bypass
bedrock or water table must be more than 2’ below bottom
Do not located in sandy soils (wouldn’t allow filtration)
Construct late in construction sequence
Use engineered soil.
Infiltration basin design
Filled with gravel; typically 40% void space
Drainage area <1 acre; located close to runoff source
Include a forebay to prevent clogging with particles
infiltration rate of soil at least .5” per hour
incorporate observation wells
Should not be used for highly polluted water
Typically does not incorporate plants
Vegetated swales
Cheaper than concrete culverts, but require more maintenance and area
Limited sediment filtration; a pretreatment of runoff
Design to convey large storms, typically 25 year storm
Side slopes 2:1 max; shallow conveyance slope preferred
100% vegetation cover to prevent erosion
Bioswales
linear bioretention areas designed to convey, filter and infiltrate runoff.
Use engineered soil, underdrains and vegetation
Flow splitter may be needed
Pools may be used to dissipate erosive energy, but have potential to disturb previously deposited sediments
Stormwater wetlands
low cost; require large area
undulating microtopography and permanent pools
rely on inflow from precipitation (unlike constructed wetlands)
stormwater depth should be max. 9” above permanent depth
72 hour drawdown (spillways)
forebay to collect sediment/trash
surface area 5-10% of catchment area
release into level spreaders or riparian areas
flowsplitter to divert excess water
catchment less than 5 acres
Problems with traditional box culverts
they restrict stream flow, causing downstream scouring, and disrupting habitat
Solution: use bridges, wide, bottomless culverts or imbed bottom of culvert beneath stream bed to allow continuous habitat`
Methods of using captured rainwater for irrigation
flood or furrow irrigation
surface ponding
Primary Wastewater Treatment
Relies on gravity: screens, settling tanks
Secondary Wastewater Treatment
Require energy input and disinfectant Constructed wetlands Intermittent sand filters Pressure dosed sand mounds Pressure dosed soil absorption fields trickling filter
Benefits of constructed wetlands for wastewater treatment
easy to construct landscape amenity provide habitat do not require energy input Effective at removing nitrates, solids and carbon oxygen (drawback) require more land (drawback) require plant maintenance
Species excellent for wastewater treatment
Typha, Scirpus, Carex (Phragmites is good but invasive)
Tertiary wastewater treatment types
nitrification trickling filter recirculating sand filter bag filters cartridge filter fine mesh screens ozone disinfection sodium hypochlorite
Composite deck board spacing
Parallel boards 3/16” apart
Best playground post material in sub zero temperatures
Powder coated steel
Most important factor in evaluating letter size for roadway signage
Speed of vehicle
Construction contract is fully executed when…
Work is complete and owner has made final payment
Project manual includes…
Bidding docs
General conditions
Supplementary provisions
Technical specifications
General conditions
Boilerplate
Rules under which project will be built
Establish rights, authority, obligations
Supplementary conditions
Specific to job What owner will provide Type of survey Phasing requirements Security, cost reporting, schedule Material substitution info Traffic control Cultural artifact discovery
Specifications include…
Invitation to bid Instructions to bidders Gen and supp conditions Bid proposal Bid bond form Contract bond form List of prevailing wages Non collusion affidavit Tech specifications
Structural soils ingredients
Gap graded angular crushed stone
Clay loam soil
Hydrogen (for binding)
Soil stockpiling guidelines
Don’t stockpile more than 6 months
Don’t pile higher than 4’
Lift
Uniform layer of fill soil
Runoff control practices during construction
Diversions Waterways Slope protection Grade control structures Outlet protection
Biotechnical erosion control measures
Live staking
Live fascines (branch bundles parallel to slope)
Brushlayering (branch bundles perpendicular to slope)
Branch packing
Live cribwall
Fiber rolls
Log terraces
Open vs closed drainage systems
Open system all runoff is conveyed to the ground on site
Closed system, runoff is conveyed through pipes to an on or off site outlet
Flashing
Thin piece of impervious metal used for waterproofing roofs, tops of windows or doors or along the top of foundations to direct water away from the structure
Angle iron
Carbon steel beam with L profile, used to frame structures; extremely stable, can bear excessive pressure snd weight
Brass pipe
Highly resistant to corrosion, water and heat damage. Soft metal, easy to create tight seal. Safe for drinking water
Butt hinge
Metal hinge with two matching leaves used to mount doors
Copper pipe
Can fail in Temps above 180. Can form condensation which can freeze and block pipes. Can give water a metallic taste. Acidic water can cause it to corrode.
Mastic
Type of resin used to attach tile to walls
Waterstop
Creates water right seal between concrete surfaces
Most common mortar joint in masonry construction
Roddenberry joint
The three types of retaining walls
Gravity, cantilever, counterfoil
Major load carrying members of a deck
Beams
Difference between screw and lag bolt
Head of the connector
Description of a township
Portion, section, tier, range
Plane survey process
Backsight I’d added to height of instrument and Foresight is deducted from height of instrument
Two types of portland cement mortar most suitable
N and S
Joints required I’m concrete to reduce cracking due to shrinkage
Control joints
Increasing the amount of water in mortar will…
Increase tensile bond strength
Decrease compressive strength
Minimum clear width for wheelchair
36”
Unified ASTM soil classification groups soils by…
Bearing capacity
Soil type least susceptible to frost avrion
Gravel
Device that prevents contamination of water bodies with petroleum
Hooded catch basin
Soil hydrologic group most likely to produce most runoff
D (least permeable)
Minimum width for handicap stall
12 feet
Water pressure calculation
Pressure=density x height x acceleration of gravity
Water density
62.4 lbs per cubic foot
Adding sulfur to soil…
Increases acidity
Vacuum breaker valve purpose
Prevents contamination of potable water
Minimum handicap parking stall width
12 feet
