3s Coordinate Eng. Systems Flashcards
S1 - List the pros (8) and cons(6) of wood structural systems.
\+ irregular forms \+ easy to erect on-site \+ plentiful & inexpensive \+ Light weight \+ Good in seismic zone \+ Renewable Source \+ compression & tension loads \+ construction possible in bad weather - thick floor assemblies - combustible - small spans/height -susceptible to insect, water damage - Requires several trades for finishing -Not best for accoustics
S3 - List the pros & cons of precast concrete structural systems. (6 pros 3 cons)
\+ integral fire protection \+ allows irregular forms \+ thin floors \+ fast on-site erection \+ flexible \+ Factory made - Heavy dead loads - Poor insulation performance - Requires crane for installation
S4 - List the pros (4) & cons (5) of site-cast concrete structural systems.
\+ integral fire protection \+ irregular forms \+ thin floors \+ high compressive strength - rqrs good weather for erection - heavy dead load - Not good in tension - Poor insulation qualities - formwork/labour intensive
S5 - List the pros(6) & cons (6) of steel structural systems.
\+ construction can occur in bad weather \+ light dead load \+ fast erection \+ small column section \+ adaptable \+ Long spans possible - rqrs fire protection - thick floors - rqrs regular grid - rqrs shear bracing - Requires specialty trades - Poor insulation performance
S6 - What 3 structural systems are best for inherent fire-resistance, particularly useful when structure exposed?
• ALL CONCRETE
• HEAVY TIMBER
• MILL CONSTRUCTION
X NOT STRUC. STEEL (weakens rapidly in fire)
S8 - What structural system is best for a thin floor system?
- pre-stressed concrete
- Post-tensioned concrete
- hollow core precast concrete
S9 - What structural system is worse for building in bad weather?
- Masonry
- site-cast concrete
Best=wood, steel, precast concrete
S10 - What structural systems are best for a highly irregular form?
Simple floor/roof framing on-site • SITE-CAST CONCRETE • LIGHT GAUGE STEEL FRAME • WOOD FRAME • MASONRY
S11 - What structural systems are best for allowing changes to the building over time?
Short-span one way systems • LIGHT-GAUGE STEEL • wood • CONCRETE • ANY ALL WOOD X NOT POST-TENSIONED
S12 - What structural systems are best for irregular grid? (2)
- SITE-CAST CONCRETE
* METAL SPACE FRAME
S13 - What structural systems are best for min. area occupied by columns/bearing walls? (7)
Long span systems • HEAVY WOOD • STEEL FRAME • STEEL TRUSS • CONCRETE WAFFLE • PRECAST CONCRETE • GLUE LAM • OPEN WEB STEEL JOIST
S14 - What structural systems are best for min. construction time for 1-2 storeys? (3)
Lightweight / Easy to form Prefab / Easy to assemble: • ANY STEEL • HEAVY TIMBER • PLATFORM FRAME
S15 - What structural systems are best for min. construction time for 4-20 storeys?
- PRECAST (prefab)
- STEEL FRAME (prefab)
- SITE-CAST (no lead-time)
S16 - What structural systems are best for min. construction time for >30 storeys?
Strong & lightweight
Prefab / Easy to assemble:
• STEEL FRAME
• PRECAST / SITE-CAST COMBO
S18 - What structural systems are best for min. on-site erection time?
Pre-processed, pre-fab, or modular: • SINGLE STOREY RIGID STEEL FRAME • conventional STEEL FRAME w HINGE CONNECTIONS • Concrete precast • pre-fab wood or heavy timber
S19 - What structural systems are best for min. no. of trades on-site?
- MASONRY
* PRECAST LOADBEARING
S20 - What structural systems are best for min. structural distress from unstable foundation?
Frame wOUT rigid joints
• STEEL (BOLTED)
• HEAVY TIMBER
• PRECAST
What structural systems are best for providing space within struc. for ducts, pipes, mech?
- TRUSS / OPEN WEB
- LIGHT GAUGE STEEL FRAME (combo w load bearing systems)
- PLATFORM FRAME (combo w load bearing systems)
Give an example of:
- Distributed Load
- Line Loads
- Punctual loads
- Distributed Load: Roof, Above grave floor slab
- Line Loads: Wall on floor
- Punctual loads: Column
What type of loads are these:
- The weight of a person
- The weight of a column
- A earthquake
- Rain/Snow loads
- Horizontal force a soil mass exerts on a vertical retaining wall.
- imposed on a structure by subsidence of a portion of the supporting soil in resulting differential settlement of its foundation.
- Hydraulic force groundwater force on a foundation system
- The weight of a person: OCCUPANT LOAD, LIVE LOAD, STATIC LOAD
- The weight of a column, DEAD LOAD,
- A earthquake: DYNAMIC LOAD, ENVIRONMENTAL LOADS
- Rain/Snow loads: LIVE LOAD, STATIC LOADS
- Horizontal force a soil mass exerts on a vertical retaining wall.: GROUND PRESSURE, DEAD LOAD, ENVIRONMENTAL LOADS, STATIC LOAD
- imposed on a structure by subsidence of a portion of the supporting soil in resulting differential settlement of its foundation.: SETTLEMENT LOAD, ENVIRONMENTAL LOADS
- Hydraulic force groundwater force on a foundation system: WATER PRESSURE, LIVE LOADS
True or false? Precipitation are static loads.
True, they are live, static loads
Which of the following loads are NOT permanent (dead) loads?* 1. Hydrostatic 2. Uniform 3. Live 4. Concentrated 5. Distributed A) 1, 3 B) 1, 5 C) 2, 4 D) 3, 5 E) 1, 2, 3 F) 1, 3, 5
A) 1, 3 - Hydrostatic & Live
What is “flutter”?
Flutter: Rapid oscillation of a membrane structure caused by the aerodynamic effects of wind
What are damping mechanism?
viscoelastic devices typically install at structure joints to absorb energy from an earthquake by progressively diminishing vibratory and oscillatory motions and prevent destructive resonances from occurring.
What are the 3 types of wind induces loads a structure must resists?
- uplifts
- sliding
- overturning
Must resist to them in all directive (positive and negative pressure)
What is differential settlement?
Uneven consolidation of the soil cause relative movement of different parts of a structure.
What serie of open-web steel joist offers longer spans, serie K or series LH/DLH?
DLH up to 44m
LH up to 18m but tends
K up to 18m but tend towards smaller spans than LH
In a steel floor, what is bridging?
Horizontal or diagonal members keeping the horizontal members to overturn. Prevent lateral movement of joists.
Quelle est l’une des conséquences de l’absence de drain dans une fondation d’une maison?*
Accumulation of water decrease the bearing capacity of the soils and increase the risk of infiltration between the foundation wall and slab
What is a Vierendeel Truss?
Vierendeel truss are framed beams structures having vertical web members rigidly connected to parallel top and bottom chords. They aren’t real trusses because their member are subject to nonaxiale forces.
What the name of this truss. What’s in compression? what is in tension? (blue,red)
Howe
Tension: Blue
Compression: Red
What the name of this truss. What’s in compression? what is in tension? (blue,red)
Pratt Flat truss
Tension: Red
Compression: Blue
Name 3 ways to get lateral stability
- Bracing - Less effective, small to med building
- Rigid frame - knee bracing, cross bracing, K bracing
- Shear wall - Wood, concrete or masonry
Define Settlement
Gradual subsiding of a structure as the soils under its foundation consolidate under loading
Factors to consider in selecting and designing the
type of foundation system for a building include: (6)
- Pattern and magnitude of building loads
- Subsurface and ground water conditions
- Topography of the site
- Impact on adjacent properties
- Building code requirements
- Construction method and risk
What’s underpinning?
Underpinning refers to the process of rebuilding or strengthening
the foundation of an existing building, or extending it when a
new excavation in adjoining property is deeper than the existing
foundation.
WHat does a key in foundation wall-spread connection?
Increase resistance to lateral slippage.
What’s the difference between damproofing and waterproofing? What material are used for each?
Damproofing: Hydrostatic pressure from groundwater will not occur; Bituminous or acrylic modified cement coating
Waterproofing: Hydrostatic pressure from groundwater will occur; Rubberized or polymer-modified asphalt, butyl rubber, bentonite clay
Name 3 types of joints and where to use them
- Isolation joint (expansion joint) where adjoining element of concrete meet to allow for movement
- Construction joint: to stop and restart construction. Also serve as expansion and control joint. Dowel or Keyed to prevent differential settlement
- Control joint, create a line of weakness to control where the jioints are, sawn joint or metal premold
What is most critical in a floor system: bending or deflection. Why?
Deflection is more important for human comfort, effects on finish flooring and ceilings
What’s that? What
Column capital . Can be used with or without a drop panel to increase resistance against punching shear
What is prestressed concrete? What for? What types (2) + description.
Pretension or posttension of the steel of reinforced concrete resulting in compressive stress to counteract the tensile stress of the applied load.
Carry greater load; lengthened span
Pretension
Steel is stretch prior to pouring
Posttension
Steel is unstressed prior to pouring then replaced. Loads equalize upward curved
What is shoring?
Shoring is the temporary structure around concrete fomwork.
Name 3 types of connections for steel structure
Bolted
Welded
Riveted
Name these profile, top to bottom
S shape - Classic I-Beam
W shape - wide flange
C shape - channel
Tubing (HSS-hollow steel section)
Define plate girders, box girders, stiffeners, castellated beams
Plate girders: build up from plates or shapes, welded or riveted together
Box girders: plate girder but with hollow cross section
Stiffeners: angles fastened to each side of a web plate to stiffen against bulking
Castellated beams: Fabricated by cutting the web in a lengthwise zigzag then welding the halves at its peak. To increase depth without increasing the weight.
Why are metal decking corrugated? What are the 3 types of metal decking+description
Metal decking are corrugated to increase the stiffness and spanning capabilities
1.Form decking - Permanent formwork for reinforced concrete slab
2.Composite - Serve as tensile reinforcement for the concrete slab with ribbed embossed pattern;
Composite action achieved by welding shear studs through the decking
3.Cellular - Welded corrugated decking to a flat steel sheet, creating cavities for wiring
What are the name of these light-gauge steel Joists. Left to right
Nestable Joist
C joist
Joist closure
If the overall constrcution is acceptable, is it preferrable to have
- more joist but less deep, or
- less joists but deeper?
- less joists but deeper.
Deeper joist=more stiffness=less deflection better for floor and ceiling finishes and human comfort
What’s A & B?
A: 51mm (2”) to joist edge
B: max diameter=1/3 of joists
What’s A?
A: 1/6 of joist; no opening in the middle third of span
