Structural Design Questions and Answers1. Is an extension or increase in floor area or height of a building or structure2. Is a method of proportioning structural elements such that computed stresses produced

in the elements by the allowable stress load combinations do not exceed specified allowable stress (also called working stress design)

3. Is any change, addition or modification in construction or occupancy

4. As to materials and type of construction, refers to approval by the building official as the result of investigation and tests conducted by the building official, or by reason of accepted principles or tests by recognized authorities, technical or scientific organizations

5. Is any structure used or intended for supporting or sheltering any use or occupancy

6. Is a building erected prior to the adoption of this code, or one for which a legal building permit has been issued

7. Is the officer or other designated authority charged with the administration and enforcement of this code, or the building official's duly authorized representative

8. Is a method of proportioning structural elements using load and resistance factors such that no applicable limit state is reached when the structure is subjected to all appropriate load combinations, this terms also used in the design of steel and wood structures

9. Is a method of proportioning structural elements such that the computed forces produced in the elements by the factored load combinations do not exceed the factored element strength this term is used in the design of concrete and masonry structures

10. Is that which is built or constructed, an edifice or building of any kind or any piece of work artificially built up or  composed of parts joined together in some definite manner

11. Is a registered civil engineer with special qualification in the practice of structural engineering

12. Is the extent of surface conditions on completion of grading13. Is in place solid rock14. Is a relatively level step excavated into earth material on which fill is to be placed15. Is earth material acquired from an  offsite location for use of grading on a

site16. Is a professional engineer licensed to practice in the field of civil

engineering17. Is the application of the knowledge of the forces of nature, principles of mechanics and

the properties of materials to the evaluation, design and construction of civil works18. Is the densification of a fill by mechanical means19. Is the mechanical removal of earth material20. Is the vertical location of the ground

surface21. Is the final grade of the site that conforms to the approved plan22. Is the stage at which the grade approximately conforms to the approved plan 23. Is an inclined ground surface the inclination of which is expressed as a ratio of vertical

distance to horizontal distance  24. Is a method of proportioning structural elements such that computed stresses

produced in the elements by the allowable tress load combinations by the allowable stress load combinations do not exceed specified allowable stress

25. Consist of the weight of all materials and fixed equipment incorporated in the building or other structure

26. Are buildings and other structures that are intended to remain operational in the event of extreme environmental loading from wind or earthquakes

27. Is a condition in which a structure or component is judged either to be no longer useful for its intended function or to be unsafe

28. Are forces or other actions that result from the weight of all building materials, occupants, and their possessions, environmental effects, differential movements and restrained dimensional changes 

29. Any metal or wood stud wall that supports .5 KN  or masonry or concrete wall that supports more than 1.0 KN per linear meter superimposed loads or any such wall supporting its own weight for more than one storey  

30. Is any wall that is not a bearing wall31. Is a wall designed to resist the later displacement of soil or other

materials32. Is a structure having all walls  at least 80%

open33. Are elements that do not qualify as part of the main wind force resisting

system34. F is the equivalent  static force to be used in the determination of wind loads for open

buildings and structure  35. p is the equivalent static pressure to be used in the determination of wind loads of the

building36. Is a factor accounts for the degree of hazard to human life and damage to

property37. Is an assemblage of structural elements assigned to provide support and stability for

the overall structure38. Is 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 supported39. V is the total design lateral force or shear at the base of the structure40. Is a structural system without a complete vertical load carrying  space frame41. Is an element at the edges or openings or at perimeter of shear walls or

diaphragms42. Is an essentially vertical truss system of the concentric or eccentric  type that is

provided to resist lateral forces43. Is  an essentially complete space frame that provides support on gravity loads44. Is a member or element provide to transfer lateral forces from a portion of a structure

top vertical elements of the lateral forces resisting system45. Is a braced frame in which the members are subjected primarily to axial forces46. Is a horizontal or nearly horizontal system acting to transmit lateral forces to the

vertical resisting elements47. Is the element of a diaphragm parallel to the applied load that collects and  transfers

diaphragm parallel to the applied load that collects and transfers diaphragm shear to the vertical resisting elements or distributes loads within the diaphragm 

48. Is a combination of moment resisting and shear walls or braced frames49. Are those structures that are necessary for emergency operations subsequent to a

natural disaster?50. Is a horizontal truss system that serves the same function as a diaphragm 51. Is a frame in which members and joints are capable of resisting  forces primarily by

flexure52. Is a masonry wall frame experientially detailed to provide ductile behavior53. Is a moment resisting frame not meeting a special detailing requirements for

ductile behavior 54. Are the earthquake load affects on structural elements common to the lateral force

resisting system along two orthogonal axes55. Is the secondary effect on shears axial forces and moments of frame members induced

by the vertical loads acting on the laterally displaced building system56. Is a wall designed to resist lateral forces parallel to the plane of the wall.57. Uses combinations of shear walls and frames designed to resist lateral forces in

proportion to their relative rigidities considering interaction between shear walls and frames on all levels

58. Is one in which the lateral stiffness than 70% of the stiffness of the story above

59. Is the story of between levels60. Is the lateral displacement of one level relative to the level above or below61. Is the story drift divided by the story

height62. Is the capacity of an element or a member to resist factor load63. Is an assemblage of framing members designed to support gravity loads and resist

lateral loads.64. Is a portion of a larger wood diaphragm designed to anchor and transfer local forces to

primary diaphragm struts and the main diaphragm65. Is the system of elements anchoring the wall to the diaphragm and those elements

within the diaphragm  66. Is  material other than water, aggregate, or hydraulic cement used as an ingredient of

concrete and added to concrete before or during its mixing to modify its properties67. Is a granular material such as sand, gravel or crushed stones and iron blast furnace slag

and when used with a cementing medium forms a hydraulic cement concrete or mortar68. Is aggregate with a dry, loose weight of 1120 kg/ cu.m. or less69. Is the unit of weight of a light weight concrete specimen cured for seven days with

neither loss nor gain of moisture at 15 deg C to 27 deg C and dried for 21 days in 50 +- 7 percent relative humidity at 23 deg C +- 1.1 deg C.

70. Is a member with ratio of height to least lateral dimension of 3 or greater used primarily to support axial compressive load

71. Are concrete flexural members of precast and cast in place concrete elements, or both, constructed is separate placements but so interconnected that all elements responds to load as a unit 

72. Is a cross section in which the net tensile strain in the extreme tension steel at nominal strength is less than or equal to the compression- controlled strain unit

73. Is the net tensile strain at balanced strain conditions

74. Is a concrete containing lightweight aggregate and has a air dry unit weight

75. Is a formed, sawed or tooled groove in a concrete structure to create a weakened plane and regulate the location of cracking resulting from the dimensional change of different parts of the structure

76. Is deformed reinforcing bars, bars and rod mats, deformed wire welded smooth wire fabric and welded deformed wire fabric

77. Is the length of embedded reinforcement required to develop the design strength of reinforcement at a critical section

78. Is the distance measured from extreme compression fiber to centroid of tension reinforcement

79. Is the length of embedded reinforcement provided beyond a critical section

80. Is a separation between adjoining parts of concrete structure 81. Is the temporary force exerted by device that introduces tension into prestressing

tendons in prestressed concrete82. Is the ratio of normal stress to corresponding strain for tensile or compressive stresses

below proportional limit of material. 83. Is an upright compression member with a ratio of unsupported height to average least

lateral dimension not exceeding of 384. Is a structural concrete with no reinforcement or with less

reinforcement85. Is reinforcement that does not conform to definition of deformed

reinforcement86. Is a structural concrete element cast in other than its final position in the structure87. Is structural concrete  in which internal stresses have been introduced to reduced

potential tensile stresses in concrete resulting from loads88. Is a method of prestressing in which tendons are tensioned before concrete is

placed89. Is structural concrete reinforced with no less than the min amounts or

prestressing tendons or nonprestressed reinforcement90. Is material excluding prestressing tendons unless specifically included91. Is a material encasing a prestressing tendon to prevent bonding the tendon with

the surrounding concrete, to provide corrosion protection and to contain the corrosion inhibiting concrete

92. Are vertical or inclined support members designed to carry the weight of the formwork, concrete and construction loads above

93. Is continuously wound reinforcement in the form of a cylindrical helix94. Is reinforcement used to resist shear and torsion stresses in a structural member. term

for flexural members95. The nominal strength multiplied by a strength reduction factor96. Is the strength of a member or cross section calculated in accordance with provisions &

assumptions the strength design method before application any strength reduction factor

97. Is the intensity of force per unit area

98. Is all concrete used for structural purposes including plain and reinforced concrete99. Is a steel element such as wire cable, bar, rod or strand or a bundle of such elements

used to impart prestress force to concrete100. Is a loop of reinforcing bar or wire enclosing longitudinal reinforcement.101. Is a member usually vertical used to enclose or separate spaces102. Is a level at witch earthquake motions are assumed to be imparted to a building. this

level does not necessarily coincide with the ground level103. Is the intensity of force per unit area104. Are portions along structural wall and structural diaphragm edges strengthened by

longitudinal and transverse reinforcement105. Is a horizontal element in plane with the connecting two shear walls106. Is the lateral displacement expected for the design basis earthquake, as required by

the governing code for earthquake resistant design107. Is a close tie or continuously wound tie108. Is the geometric volume common to intersecting members

The procedures and limitations for the design of structures shall be determined by the following factors.Zoning, site characteristics Occupancy, configuring structural system, and heightMinimum number of stories recommended to be provided with at least 3 approved recording accelerographs.14Maintenance and service of accelerographs shall be provided by the___.OwnerWho shall be responsible for keeping the actual live load below the allowable limits and shall be liable for any failure on the structure due to overloading.Occupant of the buildingThe period of continuous application of a given load or the aggregate of periods of intermittent application of the same load.Load durationMinimum area in square meters a member supports which the design live load may be reduced.14 sqm.Minimum height of any wall requiring structural design to resist loads onto which they are subjected.1.50 mts.Maximum deflection of a brittle finished wall subjected to a load of 250 Pascal applied perpendicular to said wall.1/240 of wall spanMaximum deflection of a flexible finished wall subjected to a load of 250 Pascal applied perpendicular to said wall.1/120 of wall spanMaximum floor area for a low-cost housing unit.60 sqm.

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.BaseA member or an element provided to transfer lateral forces from a portion of a structure to vertical elements of the lateral force resisting system.CollectorA horizontal or nearly horizontal system acting to transmit lateral forces to the vertical resisting elements, it includes horizontal bracing system.DiaphragmThe total designed lateral force or shear at the base of a structure.Base Shear, VAn element at edge of opening or at perimeters of shear walls or diaphragm.Boundary ElementAn essentially vertical truss system of the concentric or eccentric type which is provided to resist lateral forces.Braced FrameAn essentially complete space frame which provides supports for gravity loads.Building Frame SystemA combination of a Special or Intermediate Moment Resisting Space Frame and Shear Walls or Braced Frames.Dual SystemThat form of braced frame where at least one end of each brace intersects a beam at a point away from the column girder joint.Eccentric Braced Frame (EBF)The entire assemblage at the intersection of the members.JointThe horizontal member in a frame system, a beam.GirderAn 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.Diaphragm StrutThe boundary element of a diaphragm or a shear wall which is assumed to take axial stresses analogous to the flanges of a beamDiaphragm ChordThose structures which are necessary for emergency post-earthquake operations.Essential facilitiesThat part of the structural system assigned to resist lateral forces.Lateral Force Resisting SystemMoment resisting space frame not meeting special detailing requirements for ductile behavior.Ordinary Moment Resisting Space FrameThe displacement of one level relative to the level above or below.Story Drift

The usable capacity of a structure or its members to resist loads within the deformation limits prescribed in this document.StrengthThe lower rigid portion of a structure having a vertical combination of structural system.PlatformHorizontal truss system that serves the same function as a diaphragm.Horizontal Bracing SystemAn assemblage of framing members designed to support gravity loads and resist lateral forces.StructureA structural system without complete vertical load carrying space frame. This system provide support for gravity loads. Resistance to lateral load is provided by shear walls or braced frames.Bearing Wall SystemA structural system with essentially complete space frame providing support for gravity loads. Resistance to lateral load is provided by shear walls or braced frames.Building Frame SystemA structural system with an essentially complete space frame providing support for gravity loads. Moment resisting space frames provide resistance to lateral load primarily by flexural action of members.Moment Resisting Frame SystemIs one in which the story strength is less than 80% of that of the story above.Weak StoryAn elastic or inelastic dynamic analysis in which a mathematical model of the structure is subjected to a ground motion time history. The structure's time-dependant dynamic response to these motion is obtained through numerical integration of its equations of motions.Time History AnalysisThe effects on the structure due to earthquake motions acting in directions other than parallel to the direction of resistance under consideration.Orthogonal EffectThe secondary effect on shears and moments of frame members induced by the vertical loads acting on the laterally displaced building frame.P-delta EffectMaterial other than water, aggregate, or hydraulic cement, used as an ingredient of concrete and added to concrete before or during its mixing to modify its properties.AdmixtureConcrete that does not conform to definition of reinforced concrete.Plain ConcreteUpright compression member with a ratio of unsupported height to average least lateral dimension of less than three.PedestalRatio of normal stress to corresponding strain for tensile or compressive stresses below proportional limit of material.Modulus of Elasticity

In prestressed concrete, temporary force exerted by device that introduces tension into prestressing tendons.Jacking ForceLength of embedded reinforcement provided beyond a critical section.Embedment LengthStress remaining in prestressing tendons after all losses have occurred, excluding effects of dead load and superimposed loads.Effective PrestressLength of embedded reinforcement required to develop the design strength of reinforcement at a critical section.Development LengthFriction resulting from bends or curves in the specified prestressing tendon profile.Curvature FrictionConcrete containing lightweight aggregate.Structural Lightweight Concreteprestressing tendon that is bonded to concrete either directly or through grouting.Bonded TendonASTM A36Structural SteelBond StressThe force adhesion per unit area of contact between two bonded surface.450mmIn walls and slabs other than concrete joist construction, primary flexural reinforcement shall not be spaced farther apart than 3 times wall or slab thickness not farther than _____.d/2Spacing of shear reinforcement placed perpendicular to axis of non-prestressed member shall not exceed _____.Flexible ComponentsIs a component including its attachments having fundamental period greater than 0.60 sec.25mmThe minimum clear spacing between parallel bars in a layer must not be db not less than_____.200The slenderness ratio, kl/r of compression members shall not exceed______.25%In the determination of seismic dead load with a minimum of ___% of floor, live load shall be applicable for storage and warehouse occupancies.Vertical Geometric IrregularityStory dimension greater than 130% of the dimension of adjacent story.60 timesSpacing for a lateral support for a beam shall not exceed _____ times the least width b of compression flange or face.0.40Deep continuous flexural members have overall depth to clear span ratio greater than _____.

1.4 Dead Load + 1.7 Live LoadFactored load for strength design method.Rigid ComponentA component including its attachments having fundamental period less than or equal to 0.06 sec.Bearing Wall SystemIt is a structural system without complete vertical local carrying space frame.Allowable StressThe maximum safe stress that a material can withstand.0.75Deep simple span flexural members has overall depth to clear span ratio greater than______.Moment Resisting FrameA frame with rigid joints, in which the members and joints are capable of resisting vertical and horizontal forces primarily by flexure. it is also called a RIGID FRAME.Bearing StressContact pressure developed between two bodies.Portal MethodMethod of analyzing indeterminate modular building frames by assuming hinges at the center of beam spans and column heights.1.50dbIn spirally reinforced or tied reinforcement compression members, clear distance between longitudinal bars shall not be less than _____.Braced FrameAn essentially vertical truss system of the concentric or eccentric type that is provided to resist lateral forces.10mmThe minimum nominal diameter of steel bolts when wood plates or sill shall be bolted to foundation wall in zone 4 seismic area in the Philippines.0.70USD strength reduction factor Ø for bearing on concrete.0.90USD strength reduction factor Ø for axial tension and axial tension without flexure.0.85USD strength reduction factor Ø for post tensioned anchorage zones.0.70USD strength reduction factor Ø for axial compression and axial compression with flexure: spiral reinforced.0.75USD strength reduction factor Ø for axial compression and axial compression with flexure: tie and other reinforcement members.0.85USD strength reduction factor Ø for shear and torsion.0.90USD strength reduction factor Ø for flexure without axial load.

Minimum Diameter of Main Bars: 12 mmMinimum Diameter of Temp Bars: 10 mmMinimum Covers: 20mm for Indoors50mm if exposed to weather74mm if in contact with soilOne-way Slab Bars (Cover and Sizes)-Main Bars-Temp Bars-Minimum CoversEssential FacilitiesStructures that are necessary for emergency operations subsequent to a natural disaster.3mmMinimum size of fillet weld.4700 √f'cModulus of elasticity of concrete.Thermal StressThe stress induced as a result of restrained deformations due to changes in temperature.Inflection PointIt is a point in a beam or column where there is no moment developed.Essential FacilitiesAviation control towers fall to what type of occupancy?0.01 - 0.08Steel ratio for spiral columns ranges from _____.ρL/240The allowable deflection for any structural member loaded with dead load and live load only.100mmWhen grillage footings of structural steel shapes are used on soils, they shall be completely embedded in concrete. Concrete cover shall be at least _____ on the bottom.0.60mThe minimum distance that the toe of fill slope made to the site boundary line.10 daysBefore commencing the excavation work, the person making the excavation shall notify, in writing, the owner of the adjoining building not less than _____ days before such excavation is to be made.ⱳL/2A simply supported beam, L meters long, carrying a uniformly distributed load of ⱳ in N/m, produces a maximum shear force of _____.Flanged Bolt CouplingUsed to connect shafts.TorqueIt is a twisting force that rotates or tends to rotate a shaft.BondAdherence between materials such as bricks, mortar or plies of felt or between felts and other elements of roof systems which use bitumen or other materials as the cementing agent.

0.003The actual strain by which a concrete fails is 0.004. For safety purposes, the ACI code allowas designers to use _____.Bundled Bars:-Minimum dia: 16mm-Maximum dia: 36mm-Minimum hoop/stirrup dia: 12mm-Minimum cover: 50mm (indoor)Two to four parallel reinforcing bars put in contact as a unit.-Minimum diameter-Maximum diameter-Minimum hoop/stirrup-Minimum Covera²=b²+c²-2bcCosACosine Law (formula)GirderLarge beam supporting a smaller beam.7850kg/m³ or 490lb/ft³Weight of steel.WSD - Working Stress DesignUSD - Ultimate Strength DesignMethods of concrete design1/4 to 1/3 of the height of the buildingExcavation of floating foundation.Weight/Mass IrregularityStory mass greater than 150% of the mass of adjacent story.Weak StoryStory strength less than 80% of the story strength above.DiaphragmA Horizontal or nearly horizontal system including horizontal bracing system that act to transmit lateral forces to the vertical resisting elements.StressForce per unit area.Punching ShearThe failure of a base when heavily loaded columns strike a hole through it.Working StressActual stress due to load applied.Retaining WallSupports soil pressure.DikesSupports hydrostatic pressure along rivers.Development length (less than 300mm for deformed bars in tension)An extension of the length in the reinforcement used to develop strength required by the code.CuringSprinkling of water to improve the hydration process.

SettlementGradual downward movement of an engineering structure due to compression of the soil below the foundation.CompactionDensification of soil every 200mm.200mmMinimum thickness of road.375mmMinimum thickness of runwayaggregatesInert materials used in concrete which occupy more than 75% of the volume of the hardened concrete.Hooke's LawA law stating that, in a linear system, the restoring force is proportional to the displacement of the body acting in a direction as to restore equilibrium.Uplift PressurePressure coming from soil and water., The pressure in an upward direction against the bottom of a structure or a basement floor or a road slab with the presence of water.Critical PathSeries of interconnected activities through the network for which an activity has a zero float time and it tells the least time needed to complete the project.PedestalAn upright compression member with a ratio of unsupported height to average least lateral dimensions of less than three.10mm-25mm : 6db28mm - 36mm : 8dbMinimum bend diameters.25% of scaffolding can be removed at the slab area after 2 days of pouring and 100% of scaffolding after 28 daysWhat criterion conforms to good construction practice for the earliest time to remove scaffolding for concrete if no anticipated load is expected over poured floor.Tensile StressThe stress per square unit area of the original cross section of a material which resists its elongation.Storage WarehouseIn national building code, live load reduction is never allowed for _____.

= As/bdρThe steel ratio, , is determined from the formula _____.ρS = M/f (divided by the allowable bending stress)To determine the required section modulus S, the maximum moment should be _____.YieldWhat usually happens to reinforcing steel in a reinforced concrete slab or beam if such member is about to collapse.75mmMaximum spacing of spirals.

PierIt is an isolated column of masonry or a bearing wall not bonded at the sides into associated masonry when its horizontal dimension, measured at the right angle to the thickness, does not exceed four times its thickness.CripplingThe sharp bending or buckling when a column is loaded heavily is called _____.Shear WallThe wall that resists horizontal forces applied in a plane of the wall.Two-wayWhen the ratio of the short to the long direction of a slab is ≥ 0.5 then the slab is _____.L/20 = simply supportedL/24 = one end continuousL/28 = both ends continuousL/10 = cantileveredMinimum thickness of One-way slab.200 GPa or 200x10³ MPaModulus of Elasticity of Steel.Planted ColumnA column that is not aligned to a lower floor column.2 yearsA complete record of test of materials and of concrete shall be available for inspection during the progress of work and _____ years after completion of the project and shall be preserved by the inspecting engineer or architect for that purpose.Batter PilesPiles placed at an inclination to resist forces that are not critical.Minimum bar: 6-16mm ØMinimum spiral: 10mmØ spiral for 16mm to 32mmØ12mm Ø spiral for longitudinal larger than 32mm ØMinimum spacing: › 25mmMaximum spacing: 75mmSpiral Column:-Minimum bar-Minimum spiral-Minimum/Maximum spacingL/360The allowable deflection for any structural member loaded with live load only is _____.6-16mm Ø barsMinimum reinforcing steel for spiral columns allowed by the ACI code is ____.

Size of ties: 10mm Ø for 16mm to 32mm Ø bars:12mm Ø for main bars larger than 32mm ØMin. Ø of main bars: 16mmMin. no. of bars: 4*If S is larger than 150mm(6") provide additional ties.Min. cover: 40 (not exposed to weather):75 (in contact with soil/exposed to weather)Tied Column:-Size of ties-Minimum Ø of main bar-Minimum no. of bars-If more than 4 bars-Minimum coverLengthIn a column whose slenderness ratio is greater than 160, which has the greatest influence on its tendency to buckle under a compressive load.0.70As per ACI code, the capacity reduction factor of concrete members according to type of stress bearing is _____.Min. Ø of bot bars: 12mm ØMin. Ø of top bars: 12mm ØMin. cover: 20mm (indoor)50mm (exposed to weather)75mm (in contact with soil)Two-way slab:-Minimum Ø of bottom bars-Minimum Ø of top bars-Minimum coverShearA force or load acting across a beam near its support.ⱳL²/8Maximum moment of a simply supported beam whose span length is L, in meters, carrying a uniformly distributed load of ⱳ in N/m is _____.SpanDistance between two supports.200mmConcrete filled driven piles of uniform section shall have a nominal outside diameter of not less than _____.50%The slope of cut surfaces shall be no steeper than _____% slope.40dbIndividual bars within a bundle terminated within the span of flexural members shall terminate at different points with at least _____ stagger.4 piecesGroups of parallel reinforcing bars bundled in contact to act as one unit shall be united to ____ pieces in one bundle.

1:3 to 1:7 or 0.30 to 0.70Water-cement ratio.4th powerThe moment of inertia of any plane figure can be expressed in unit of length to the _____.Impact LoadWhat do you call the loads brought about by elevators and machinery or equipment's sudden movements.1. Wind Load2. Seismic Load3. Ice Load4. Snow Load5. Soil Pressure6. Hydrostatic Pressure6 environmental loads.Flexural RigidityWhat resists bending?Early Setting CementRapid hardening cement is actually called _____.Jacking ForceTemporary force exerted by a device that introduce tension into a pre-stressing tendon.Soft Story or Stiffness IrregularityIt is one in which the lateral stiffness is less than 70% of the stiffness of the story above or less than 80% of the average stiffness of the three stories above.2400kg/m³ or 150lb/ft³Weight of concrete.Flat SlabType of concrete floor which has no supporting beams.