Junior Engineer key terms

A design method that checks a structure against defined conditions of failure, such as collapse or excessive deflection, using factored loads and factored resistances to keep the probability of failure acceptably low.

A multiplier applied to nominal loads to account for uncertainty and variability, producing the design load used in limit state checks. Values differ by load type and combination.

A condition in which a structure remains safe but becomes unfit for use because of deflection, vibration, or cracking. Checked against unfactored loads rather than collapse criteria.

The ratio of a material's or system's capacity to the load or stress actually applied. A value above one indicates reserve strength; the margin covers uncertainty in loads and properties.

A plot of applied stress against resulting strain for a material under load. Its slope gives stiffness, its peak gives strength, and its shape reveals ductility or brittleness.

The stress at which a material begins to deform permanently, marking the end of elastic behavior. Commonly reported as a 0.2 percent offset value for metals without a sharp yield point.

The ratio of stress to strain within the elastic range of a material, expressing its stiffness. A higher value means less deformation for a given applied stress.

The ability of a material to undergo large plastic deformation before fracturing. Ductile behavior provides warning before failure and allows redistribution of internal forces.

The internal rotational effect produced in a beam by loads acting at a distance from a section. It causes one face to be in tension and the opposite face in compression.

The internal force acting parallel to a cross section of a member, tending to slide one part past the adjacent part. It varies along a beam according to the applied loads.

A geometric property of a cross section equal to its second moment of area divided by the distance to the extreme fiber. Used to convert bending moment into maximum bending stress.

A geometric measure of how a cross section's area is distributed about an axis, governing its resistance to bending. Often called moment of inertia in structural work.

The displacement of a structural member from its unloaded position under load. Excessive deflection can crack finishes, pond water, or impair serviceability even when strength is adequate.

A field test in which freshly mixed concrete is placed in a standard cone, the cone removed, and the drop in height measured as an indicator of workability and consistency.

A laboratory compression test on cured concrete specimens, usually cubes or cylinders, to verify that the hardened mix achieves its specified characteristic strength at a stated age.

The strength value below which a defined small percentage of test results is expected to fall, used as the basis for structural design values before partial factors are applied.

The ease with which fresh concrete or mortar can be mixed, placed, compacted, and finished without segregation. It is influenced by water content, aggregate grading, and admixtures.

The separation of coarse aggregate from mortar or paste in a concrete mix, often caused by over-wet mixes, excessive drop heights, or poor handling during placement.

The process of removing entrapped air from freshly placed concrete or soil by vibration or mechanical effort, increasing density, strength, and impermeability.

A laboratory procedure that determines the maximum dry density of a soil and the moisture content at which it occurs, providing a benchmark for field compaction control.

An in-situ measurement of compacted soil density, often by sand replacement or nuclear methods, compared with laboratory reference values to confirm that specified compaction has been achieved.

A priced or unpriced schedule listing work items with descriptions and measured quantities, prepared from drawings and specifications so that tenderers price the same scope consistently.

The process of measuring and listing the quantities of materials and work from drawings and specifications, forming the basis of estimates, bills of quantities, and material ordering.

A published set of rules governing how work is described and measured for quantities, including what is included or excluded and how deductions are treated.

A drawing in which all dimensions are reduced or enlarged by a constant ratio, stated on the sheet, so that real sizes can be derived by measuring and converting.

A method of representing a three-dimensional object by separate two-dimensional views projected onto perpendicular planes, typically plans, elevations, and sections.

A view showing an object as if cut by a plane, revealing internal construction, layer build-up, and hidden detail that exterior views cannot show.

The field operation of transferring positions, levels, and dimensions from design drawings to the ground using survey instruments, pegs, and reference lines before construction begins.

A fixed point of known elevation or coordinates used as a reference for leveling and setting out. Temporary benchmarks are established on site and protected from disturbance.

The surveying operation of determining the relative heights of points, usually by reading a graduated staff through a leveling instrument set on a stable tripod.

An electronic surveying instrument combining an angle-measuring theodolite with an electronic distance meter and onboard computer, used for coordinate measurement and setting out.

The longest sequence of dependent activities through a project network, determining the shortest possible project duration. Any delay on it delays completion unless compressed.

The amount of time an activity can be delayed without delaying the project or a successor. Activities on the critical path have zero total float.

A bar chart displaying activities against a calendar time axis, showing start and finish dates, durations, and often progress, dependencies, and milestones.

A formal written instruction authorizing a change to the scope, quality, or timing of contracted work, with valuation of cost and time effects under the contract.

A percentage withheld from interim payments under a construction contract and released at stated stages, providing the client security for defects and non-completion.

A document issued periodically by the contract administrator certifying the amount due to the contractor for work executed, less retentions and previous payments.

A written description of how a construction activity will be carried out, including sequence, plant, labor, temporary works, and controls, often required before high-risk work starts.

A structured process of identifying hazards, evaluating the likelihood and severity of harm, and recording controls to reduce risk to an acceptable level.

A ranked order of risk-reduction measures, from eliminating the hazard and substituting it, through engineering and administrative controls, to personal protective equipment last.

A formal documented authorization controlling high-risk activities, confirming that specified precautions are in place before work starts and that the area is safe on completion.

A procedure for isolating energy sources and fitting locks and tags so equipment cannot be re-energized while maintenance or repair is in progress.

A project document listing the inspections and tests to be performed, the acceptance criteria, the responsible parties, and the hold points requiring sign-off before work proceeds.

A stage in a process where work must not continue until a specified inspection or approval has been completed and recorded by the authorized party.

A record describing work or material that fails to meet specified requirements, including the nature of the failure, disposition, and corrective action taken.