Structural Design and Building Code Terminology

Comprehensive vocabulary flashcards covering structural engineering terms, building code provisions, concrete and steel design limits, and timber specifications.

Structural Design Limitations and Procedures

Determined by zoning, site characteristics, occupancy, configuring structural system, and height.

Recording Accelerographs Recommendation

Recommended to have at least 3 approved recording accelerographs for buildings with a minimum of $14$ stories.

Accelerograph Maintenance Responsibility

Maintenance and service of accelerographs shall be provided by the owner.

Live Load Maintenance Responsibility

The occupant of the building is responsible for keeping the actual live load below allowable limits and liable for any structural failure due to overloading.

Load Duration

The period of continuous application of a given load or the aggregate of periods of intermittent application of the same load.

Live Load Reduction Area Threshold

A minimum supported area of $14\text{ sqm}$ by a member before the design live load may be reduced.

Structural Wall Design Height Threshold

Minimum height of $1.50\text{ mts}$ for any wall requiring structural design to resist loads onto which it is subjected.

Brittle Finished Wall Deflection Limit

$1/240\text{ of wall span}$ when subjected to a load of $250\text{ Pascal}$ applied perpendicular to the wall.

Flexible Finished Wall Deflection Limit

$1/120\text{ of wall span}$ when subjected to a load of $250\text{ Pascal}$ applied perpendicular to the wall.

Low-Cost Housing Maximum Floor Area

$60\text{ sqm}$.

Base

The level at which the earthquake motions are considered to be imparted to the structure or the level at which the structure, as a dynamic vibrator, is supported.

Collector

A member or an element provided to transfer lateral forces from a portion of a structure to vertical elements of the lateral force resisting system.

Diaphragm

A horizontal or nearly horizontal system acting to transmit lateral forces to the vertical resisting elements, including horizontal bracing systems.

Base Shear ($V$)

The total designed lateral force or shear at the base of a structure.

Boundary Element

An element at the edge of an opening or at perimeters of shear walls or diaphragms.

Braced Frame

An essentially vertical truss system of the concentric or eccentric type which is provided to resist lateral forces.

Dual System

A combination of a Special or Intermediate Moment Resisting Space Frame and Shear Walls or Braced Frames.

Eccentric Braced Frame (EBF)

That form of braced frame where at least one end of each brace intersects a beam at a point away from the column girder joint.

Joint

The entire assemblage at the intersection of the members.

Girder

The horizontal member in a frame system (a beam), or the major horizontal supporting member of the floor system.

Diaphragm Strut

An element of a diaphragm parallel to the applied load which collects and transfers diaphragm shear to vertical resisting elements or distributes loads within the diaphragm; such members may take axial tension or compression.

Diaphragm Chord

The boundary element of a diaphragm or a shear wall which is assumed to take axial stresses analogous to the flanges of a beam.

Essential Facilities

Those structures which are necessary for emergency post-earthquake operations.

Lateral Force Resisting System

That part of the structural system assigned to resist lateral forces.

Ordinary Moment Resisting Space Frame

A moment resisting space frame not meeting special detailing requirements for ductile behavior.

Story Drift

The displacement of one level relative to the level above or below.

Strength

The usable capacity of a structure or its members to resist loads within the prescribed deformation limits.

Platform

The lower rigid portion of a structure having a vertical combination of structural system.

Horizontal Bracing System

Horizontal truss system that serves the same function as a diaphragm.

Structure

An assemblage of framing members designed to support gravity loads and resist lateral forces.

Bearing Wall System

A structural system without a complete vertical load carrying space frame that provides support for gravity loads, with resistance to lateral load provided by shear walls or braced frames.

Building Frame System

A structural system with an essentially complete space frame providing support for gravity loads, where resistance to lateral load is provided by shear walls or braced frames.

Moment Resisting Frame System

A structural system with an essentially complete space frame providing support for gravity loads, in which moment resisting space frames provide lateral load resistance primarily by flexural action of members.

Weak Story

A story in which the story strength is less than $80\%$ of that of the story above.

Time History Analysis

An elastic or inelastic dynamic analysis in which a mathematical model of the structure is subjected to a ground motion time history, obtaining time-dependent dynamic response through numerical integration of equations of motion.

Orthogonal Effect

The effects on the structure due to earthquake motions acting in directions other than parallel to the direction of resistance under consideration.

P-delta Effect

The secondary effect on shears and moments of frame members induced by the vertical loads acting on the laterally displaced building frame.

Admixture

Material other than water, aggregate, or hydraulic cement, used as an ingredient of concrete and added before or during mixing to modify its properties.

Plain Concrete

Concrete that does not conform to the definition of reinforced concrete.

Pedestal

An upright compression member with a ratio of unsupported height to average least lateral dimension of less than three.

Modulus of Elasticity

Ratio of normal stress to corresponding strain for tensile or compressive stresses below the proportional limit of the material (represented as $E$ in $e = \frac{PL}{AE}$).

Jacking Force

In prestressed concrete, the temporary force exerted by a device that introduces tension into prestressing tendons.

Embedment Length

Length of embedded reinforcement provided beyond a critical section.

Effective Prestress

Stress remaining in prestressing tendons after all losses have occurred, excluding the effects of dead load and superimposed loads.

Development Length

Length of embedded reinforcement required to develop the design strength of reinforcement at a critical section.

Curvature Friction

Friction resulting from bends or curves in the specified prestressing tendon profile.

Structural Lightweight Concrete

Concrete containing lightweight aggregate.

Bonded Tendon

A prestressing tendon that is bonded to concrete either directly or through grouting.

ASTM A36

Standard specification for Structural Steel.

ASTM A514

Standard specification for High-Yield Strength Quenched and Tempered Alloy Steel Plate, Suitable for Welding.

Beam Bar Bundling Rule

Bars larger than $32\text{ mm}$ in diameter shall not be bundled in beams.

Prestressed Concrete Primary Cover

Minimum concrete cover of $40\text{ mm}$ for prestressed concrete beams and columns for primary reinforcements.

Poisson's Ratio

In a material under tension or compression, the absolute value of the ratio of transverse strain to the corresponding longitudinal strain.

Slenderness Ratio (Column)

In a column, the ratio of its effective length to its least radius of gyration.

Torsion

A quantity which measures the resistance of the mass to being revolved about a line.

Flat Slab

A type of concrete floor which has no beam.

Shear

The tendency for one part of a beam to move vertically with respect to an adjacent part.

Deformation

A change in shape of a material when subjected to the action of force.

Yielding Stress

The maximum value of tension, compression, or shear respectively that the material can sustain without failure.

Stress

The means by which a body develops internal resistance, defined as intensity of force per unit area.

Allowable Stress

The greatest stress which a material is capable of developing without permanent deformation remaining upon the complete release of stress.

Tie / Stirrup

Loop of reinforcing bar or wire enclosing longitudinal reinforcement.

Stiffness Ratio

The measure of stiffness of a material.

Punching Shear

The failure in a base when a heavily loaded column strikes a hole through it.

Deflection

The deformation of a structural member as a result of loads acting on it.

Nominal Thickness of Timber

$6\text{ inches}$.

Equilibrium

A state where the sum of forces in the orthogonal directions and the sum of all moments about any points are zero.

Concrete Test Records Retention

Complete records of tests conducted (slump, compression test, etc.) shall be preserved for a period of not less than $2\text{ years}$.

Wood Board Thickness Specification

Not less than $1'' \times 4''$.

Run

The distance from the first to the last riser of a stair flight.

Portable Hand Router

A high-speed rotary shaping hand power tool used to make smooth cutting and curving on solid wood.

Wood Defects

Heart shake, cup shake, star shake, and knots.

Dressed Lumber

Smoothed or planed lumber.

Cross-Cut Saw

The hand saw classification other than a rip-cut saw.

Live Load

The occupancy load which is either partially or fully in place or may not be present at all.

Effective Length

The distance between inflection points in the column when it breaks.

Volume

The amount of space measured in cubic units.

Contraction Joint

An expansion joint of adjacent parts of a structure to permit expected movements between them.

Total Run

The total of all tread widths in a stair.

Bond Stress

The force adhesion per unit area of contact between two bonded surfaces.

Purlin

A structural member spanning from truss to truss or supporting a rafter.

Steel Truss Camber Size ($25\text{ m}$ Truss)

Equal to the Size of Dead Load Deflection.

Shear Connector

A connector such as a welded strut, spiral bar, or short length of channel which resists horizontal shear between elements.

Shearing Stress

The force per unit area of cross section which tends to produce shear.

Hook's Law

The law that relates the linear relationship between stresses and strains.

Timber Bolt Parallel Spacing

Minimum spacing of bolts parallel for parallel to grain loading equal to $4 \times \text{diameter of bolt}$, measured from bolt centers.

Timber Loaded Edge Distance

Edge distance for perpendicular to grain loading shall be at least $4 \times \text{diameter of bolt}$.

Timber Bolt Row Spacing (Perpendicular to Grain)

Spacing between rows of bolts shall be at least $2.5$ times bolt diameter for an $L/d$ ratio of $2$.

Timber Connection Bolt Minimum Diameter

$12\text{ mm}$ according to NSCP specifications.

Solid Timber Column Slenderness Ratio Limit

Shall not exceed a slenderness ratio of $50$.

Nail and Spike Minimum Penetration

Not less than $11\text{ diameters}$ when wire gauges or lengths are not specified in NSCP specifications.

Sawn Lumber Bending Notch Limit

Notches in sawn lumber bending members shall not exceed $1/6\text{ depth of member}$.

Sawn Lumber Prohibited Notch Location

Notches in sawn lumber shall not be located in the Middle Third Span.

Joist Notch Depth Limit

Notches in the top and bottom of joists shall not exceed $1/4\text{ the depth}$.

Structural Steel Tension Allowable Stress (Gross Area)

$0.60\text{ of specified min. yield stress}$.

Structural Steel Tensile Allowable Stress (Effective Area)

$0.50\text{ of specified minimum tensile strength}$.

Pin Connected Members Allowable Tension (Net Area)

$0.45 F_y$.

Structural Steel Allowable Shear Stress

$0.40 F_y$ on the cross-sectional area effective in resisting shear.

Elevator Support Impact Load Increase

The assumed live load shall be increased by $100\%$ to provide for impact.

Compression Member Slenderness Ratio Limit

Shall not exceed $200$.