LARE Section 1 key terms

The maximum load a soil can support per unit area without failing or settling excessively. It governs footing size and is estimated from soil tests, density, and moisture conditions.

The steepest slope at which loose granular soil remains stable without sliding. It reflects internal friction and is used to judge stable grading, berms, and stockpile side slopes.

The downward movement of soil or a structure under load. Uneven settlement cracks paving, walls, and foundations, so designers balance cut and fill and improve weak subgrades.

Mechanical densification of soil by removing air voids, usually in thin lifts with rollers. Higher density raises bearing capacity and reduces settlement and permeability.

The speed at which water moves through soil, often measured as inches per hour in a percolation test. It determines whether infiltration practices or septic systems can work on a site.

The highest depth groundwater reaches during the wet season. It constrains basements, infiltration basins, and foundations, and is often higher than a single dry-season reading suggests.

Earthmoving that removes soil from high areas (cut) and places it in low areas (fill) to create grades. Balancing volumes on site reduces hauling cost and disturbance.

Reshaping ground surfaces to direct water, provide usable slopes, and tie structures to the land. It sets elevations, drainage patterns, and access, and must respect ADA slope limits.

A line on a plan connecting points of equal elevation. Spacing shows steepness: closely spaced contours mean steep slopes, widely spaced ones mean gentle ground.

A point marked on a drawing with its exact ground elevation. Spot elevations supplement contours to fix critical grades at corners, inlets, and thresholds.

The slope perpendicular to the direction of travel on a path or ramp. It is limited to prevent tipping and ponding, and is checked separately from running slope.

The slope measured along the direction of travel on a walk or ramp. Standards cap it, and ramps require landings where the rise or run exceeds limits.

A continuous path meeting width, surface, slope, and clearance requirements so people using wheelchairs or other mobility aids can travel. It must connect entrances, amenities, and parking.

The unobstructed distance between edges, walls, or objects along a route. It is measured at the narrowest point and excludes protruding items like planters or signage.

The space needed for a wheelchair or vehicle to change direction. Designers check it at dead ends, corners, and parking aisles to ensure usable circulation.

A shallow, vegetated channel that conveys and infiltrates stormwater. Swales slow runoff, filter pollutants, and reduce the need for pipes when grades and soils allow.

A depression that temporarily stores stormwater and releases it slowly through a controlled outlet. It reduces peak flows and downstream flooding compared with direct discharge.

A ratio expressing the fraction of rainfall that becomes surface runoff for a given surface. Impervious surfaces have high values; vegetated soils have low values.

The share of a site covered by surfaces that block infiltration, such as pavement and roofs. It drives runoff volume and is often capped by zoning or stormwater rules.

A surface that lets water pass into a stone reservoir and underlying soil. It works only where soils drain adequately and maintenance keeps pores from clogging.

The rate at which water enters soil from the surface, often limited by silt or clay layers. It determines the size of infiltration practices and whether they are feasible.

The resistance of a hillside or embankment to sliding or collapse. It depends on soil strength, water pressure, vegetation, and steepness, and can be worsened by grading.

Measures that prevent soil from detaching and moving, such as mulch, blankets, and check dams. They are applied during construction before permanent vegetation establishes.

Practices that capture soil already moving in runoff, such as silt fence and sediment traps. They complement erosion control by protecting waterways and storm systems downstream.

The relative proportions of sand, silt, and clay in soil. Texture influences drainage, fertility, and workability, and is judged by feel or laboratory analysis.

The arrangement of soil particles into aggregates and pores. Good structure supports roots, air, and water movement, and can be damaged by compaction or tilling.

A measure of soil acidity or alkalinity on a 0 to 14 scale. It controls nutrient availability, so plant selection and amendments depend on it.

The dry mass of soil per unit volume, including pore space. High values indicate compaction and poor aeration, which restrict root growth and infiltration.

The upper, organic-rich soil layer where most roots and biological activity occur. It is stockpiled and reused during construction to support planting success.

Soil that formed under saturated, oxygen-poor conditions and shows characteristic colors or mottling. Its presence helps identify wetlands subject to regulation.

The field process of mapping wetland boundaries using vegetation, soils, and hydrology indicators. It determines regulated areas and buffers that constrain site design.

Land adjacent to a water body that is inundated during floods, often mapped by recurrence interval. Development there faces elevation, insurance, and environmental limits.

A fixed point of known elevation or coordinates used as a reference for surveying. Accurate benchmarks anchor grading, layout, and as-built verification.

Land dedicated or acquired for streets, utilities, or public access. It defines where public improvements may occur and where private work needs permits.

A legal right to use another's land for a specific purpose, such as utilities or access. It restricts what can be built there even though ownership remains with the landowner.

The minimum distance a building or improvement must be from a property line or other feature. It is set by zoning and shapes building envelope and site layout.