LARE Section 4 cheat sheet

Contour interval is the vertical distance between adjacent contour lines; a steeper slope produces contours spaced closer together, and slope percent = (rise ÷ run) × 100.

Grading formula: percent slope = vertical change ÷ horizontal distance × 100; convert to degrees with the arctangent of the slope ratio.

Spot elevations and contour lines must agree; interpolating between contours assumes uniform slope along the line connecting them.

Cut and fill balance means total cut volume equals total fill volume on site; unbalanced earthwork requires importing or exporting soil at added cost.

The 100-year floodplain is the area inundated by a flood with a 1 percent annual exceedance probability; the 500-year floodplain is 0.2 percent.

Base flood elevation (BFE) sets the regulatory elevation for construction; freeboard is additional height above BFE required by code or ordinance.

Universal accessibility route requirements: maximum running slope 1:20 (5 percent), maximum cross slope 1:48 (about 2 percent), and a firm, stable, slip-resistant surface.

Drainage design relies on the rational method Q = CiA, where Q is peak runoff, C is the runoff coefficient, i is rainfall intensity, and A is drainage area.

A landscape architect's standard of care is the degree of care and skill ordinarily exercised by members of the profession under similar circumstances.

Plan scale: 1 inch = 20 feet means one drawing inch equals 240 drawing inches on the ground; a graphic scale remains accurate when a drawing is enlarged or reduced.

Bearing is measured from north and written as an angle with a quadrant letter (for example, N 45° E); azimuth is measured clockwise from north from 0° to 360°.

A legal description by metes and bounds follows boundary courses and distances from a point of beginning; a plat map records subdivided lots by block and lot number.

A benchmark is a fixed point of known elevation; a temporary benchmark (TBM) is established for a project and must be tied to a permanent datum.

USGS topographic maps commonly use a 1:24,000 scale with 10-foot contour intervals in flat terrain; quadrangle sheets show planimetric and topographic features.

Construction documents typically comprise drawings, specifications, and the contract documents; specifications govern over drawings when a conflict exists unless the contract states otherwise.

Detail drawings show a small area at large scale (for example, 1 inch = 1 foot); plan views show the site at small scale (for example, 1 inch = 50 feet).

A soils report provides bearing capacity, seasonal high water table, permeability, and shrink-swell potential used to size footings and paving sections.

Tree protection zones are commonly established at a radius equal to the tree's dripline or 1 foot of radius per inch of trunk diameter, whichever is greater per local standards.

Concrete mix design is specified by compressive strength at 28 days; typical landscape flatwork uses 3,000–4,000 psi with air entrainment for freeze-thaw durability.

Portland cement concrete curing requires adequate moisture and temperature; cold-weather concreting requires protection from freezing until the concrete reaches sufficient strength.

Asphalt paving section: subgrade, aggregate base, and hot-mix asphalt surface; compaction is measured as a percentage of maximum dry density by standard Proctor test.

Unit paving (pavers) requires edge restraint and a compacted base; permeable pavers use open-graded aggregate and are sized for storage and infiltration.

The AIA A201 General Conditions establishes the architect's role in administration, including site visits and issuance of clarifications and interpretations.

A change order is a written modification to the contract signed by owner and contractor; a construction change directive directs work before a price is agreed.

A request for information (RFI) seeks clarification from the design professional; the response may become a clarification or a change order.

Submittals (shop drawings, product data, samples) are reviewed for conformance with the design concept and information in the contract documents, not for approval of means and methods.

Substantial completion is the stage when the work is sufficiently complete for its intended use; it triggers warranties, retainage release, and the start of the correction period.

Critical path method (CPM): the critical path is the longest-duration sequence of dependent activities; any delay on it delays project completion.

Float (slack) is the amount of time an activity can slip without delaying the project; total float equals late finish minus early finish.

Cost estimating methods: unit cost (cost per square foot or per unit), assembly cost, and parametric estimating; order-of-magnitude estimates are less accurate than detailed estimates.

A bid form, instructions to bidders, and general and supplementary conditions are core components of the construction contract documents.

Retainage is a percentage of each payment withheld by the owner until completion; it protects the owner against incomplete or defective work.

Lien rights allow contractors and suppliers to claim against the property for unpaid work; lien waivers release those rights upon payment.

Scheduling techniques include Gantt bar charts (good for communication) and network diagrams (good for showing dependencies and float).

A punch list records incomplete or defective items identified at substantial completion and must be resolved before final payment.

Risk allocation in contracts is managed through indemnification, insurance requirements, and bonding (performance and payment bonds).