Active soils – A non-load bearing soil mass that is moving due to changing moisture levels.
Backfill – The replacement of excavated aggregate into a hole or against a structure. Man placed soils that are usually compacted into an area to re-level an area.
Bell Bottom Pier – A concrete friction piling that has a bell shaped bearing surface. A pier that has an enlarged base in order to develop much of its capacity through end bearing rather than through skin friction along its shaft.
Bottle Jack – A hydraulic devise used to support an automobile (not a house or commercial structure)
Bowing Walls – An inward movement of a basement wall due to excessive lateral pressure on the exterior of a structure. A wall that is retaining earth that is showing signs of lateral inward movement, possibly due to excessive lateral earth pressure.
Carbon Fiber Strips – Strips of carbon fiber material that are used on the inside of walls to inhibit horizontal bowing of the walls and subsequent cracking. Carbon fiber strips work well and are usually used before the cracks in the wall become too excessive.
Cleat Anchor – A dead-man that are placed outside of the active soil wedge to provide lateral support to walls retaining earth.
Consolidation – A reduction in volume of a soil mass and is accompanied by outflow of water from the soil pores. Usually this occurs when weight is added like with a home’s foundation weight, when water is present in the soil, your home may experience consolidation as a result.
Crawl Space – A shallow foundation type that incorporates an air space between the soil and the living space. These foundations are generally constructed with concrete block or stone founded on a spread type footing.
Differential Settlement or Movement – The difference in vertical foundation movement at various locations around a structure usually causing structure distortion.
Drywall Cracking – These cracks develop due to shrink/expand natures of construction materials or foundation failures. The cracks generally develop at corners, or at door and windows, sometimes pointing toward the areas of failure.
Earth Anchor – A device installed in undisturbed soils designed to stabilize or reduce the future risk of horizontal movement of basement and retaining walls. i.e. (cleat or dead-man anchor).
Eccentricity – This can be referred to as the distance of a reaction force from the center of gravity of a load causing shear and bending forces within the structural support.
Expansive Soils – Usually fine grain soils that exhibit large shrink and swell volumes with changes in the soil’s moisture content. Bentonite is a volcanic ash that has weathered to relatively pure montmorillonite, a highly expansive clay type.
Footing – An enlargement at the bottom of a foundation wall, pier, or column to distribute the load of a structure to the underlying soils.
Footing Drain – A drainage system that con consist of solid or slotted pipe encapsulated within free draining granular material, such as gravel, at or below footing levels, providing a free path for excessive water to be routed away from a structure.
Foundation Cracks – Fractures in concrete walls or slabs generally derived from differential settlement or lateral pressures.
Foundation Engineer – A professional civil, structural or geotechnical engineer that specializes in the design or remediation of foundations.
Foundation Movement – Post-construction movement of a foundation system that is detectable by changes in elevation that is usually accompanied by visible signs of distress, such as drywall cracks, doors and windows out of square in their frames, concrete cracks, etc.
Foundation Repair – The trade of underpinning or stabilizing a structure that has moved from its originally constructed design.
Heaving –Vertical movement upward of a floor slab or foundation from its designed elevation which can be associated with expansive soils.
Helical Pile – Screw Pile, Screw Anchor Manufactured steel deep foundation element consisting of a central shaft and one or more helical bearing plates, each with a uniform defined pitch. A helical pile is installed by rotating it into the ground and a pile’s capacity is determined by the force or torque needed to advance it into the underlying soil layers.
Horizontal Cracks – Fractures in walls and/or basement walls causing bowing or leaning that is generally caused by excessive hydrostatic or lateral earth pressures.
Hydraulic Torque Motor or Gear Motor – A heavy duty planetary gear drive that is used to hydraulically install helical piles.
Hydrostatic Pressure – Pressure that is exerted by a fluid due to its weight. Pooling of water at the surface or below grade are examples.
Lateral Pressure – The horizontal pressures exerted upon a wall by surrounding soils.
Load Bearing Stratum – A layer of suitable soils or bedrock that has adequate capacity to accept and dissipate the force imposed upon it by a shallow or deep foundation element.
Mud Jacking – A process by which high pressured grout is pumped under concrete to fill voids in an attempt to recover lost elevation. This grout slurry occupies the space between the foundation element and the failing soil.
Pier or Pile– A vertical load-bearing member such as an intermediate support for adjacent ends of two spans. The IBC defines a pier that is limited to a length-to diameter ratio of 30 or less and a pile has a length-to-diameter ratio larger than 30.
Plate Anchor – A device installed in undisturbed soils designed to stabilize or reduce the future risk of horizontal movement of basement and retaining walls. i.e. (cleat or dead-man anchor).
Pressed Concrete Pier – A concrete cylinder that is driven directly below the foundation by bottle jacks.
Resistance Pier or Steel Pier – An underpinning device that is hydraulically or dynamically driven into the soil to a load bearing stratum and provides its support.
Sheetrock or Drywall Cracks – These cracks develop due to shrink/expand natures of construction materials or foundation failures. The cracks generally develop at corners, door and windows in a wedge shaped manner, pointing toward suspect areas of failure.
Sinking or Settling Walls – Vertical movement of a foundation wall due to undersigned or consolidation of soils supporting the structure.
Skin Friction – The frictional resistance developed between soil and a structure or between soil and a deep foundation.
Slab Cracks – Can be categorized as either a shrinkage crack, settlement crack or heaving crack.
Slab Jacking or Mud Jacking– A process by which high pressured grout is pumped under concrete slabs to fill voids.
Stair-Step Crack – A fracture in a brick or block wall that progresses upward along mortar joints. These cracks can be from either lateral pressures or differential settlement.
Steel Pier or Resistance Pier – High strength structural steel tubing that is hydraulically driven into the underlying soil to a load bearing stratum to underpin a foundation and to provide additional foundation support.
Structural Damage – Distress in building components where things have shifted, such as drywall cracking, door and window frames out of square, concrete cracks, etc. Damage that causes structural instability should be corrected immediately.
Structural Distress – A change caused by movement (foundation, framing, soil, thermal, etc.) that is reflected by the creation of cracking.
Sump Pump – A mechanical pump used to remove water that has accumulated in a below grade pit. A sump pit, commonly found in the home basement, is simply a hole to collect water. The water may enter via the perimeter drains of a basement waterproofing system, funneling into the pit.
Synchronized Lift – A precision system that allows uniformed elevation recovery and permanent stabilization while minimizing stress to the structure.
Tie Backs – A helical anchor installed horizontally through a failing wall into suitable load bearing soils that provides lateral support through the anchor’s helices. Used on new and existing walls for horizontal and vertical support and slope stabilization.
Total Settlement – The total settlement of any part of a structure from the design or pre-settlement elevation. Some magnitude of settlement is generally accounted for in a structure’s original design.
Underpinning – Process where a deep foundation element such as a helical pile or resistance pier is installed to provide additional foundation support or to completely transfer the structural foundation loads to adequate bearing soils typically well below the less suitable problem soils.
Vertical Cracks – Vertical fractures in a structure’s foundation or walls generally caused by excessive total or differential settlement.
Void Filling – The low pressure injection of grout slurry to fill the space between the foundation element and the failing soil.
Waterproofing – To make impervious to water by various materials and methods, or a technique for rerouting water to a common collection point and to discharge outside the structure either by mechanical means or gravity.
Wall Plate – A heavy duty steel plate placed on the structure’s wall designed to transfer the axial force from the lateral anchoring system and earth anchor to the distressed wall.