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PREVIOUS QUIZZES

  • June 29, 2018
    Winner: Vincent Wang, APOC Engineering Ltd.
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    Question:
    Various improvements can be implemented to improve the stress-strain response of seven-wire strand tendons, which are used for both stay cables and internal prestressing. Based on the figure, what labelling order correctly lists the stress-strain curves for stress-relieved, low-relaxation, untreated, and mild steel tendons?
    Correct Answer:
    bii, i, iii, iv
    Incorrect Answers:
    ai, ii, iii, iv
    ciii, iv, i, ii
    div, i, ii, iii
  • June 8, 2018
    Winner: Jacek Doniec, WSP
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    Question:
    Pier blades, such as the one shown in the figure, are often employed for part of the substructure in long continuous bridge units. Spreading the pier blades further apart gives what advantage to the structure?
    Correct Answer:
    cIncreased fixity for unbalanced cantilever rotation about the bridge's transverse axis during construction.
    Incorrect Answers:
    aA decrease in the size of the supporting foundation below the pier blades.
    bIncreased fixity for seismic rotation demands about the bridge's longitudinal axis in its permanent condition.
    dDecreased fixity for shear displacements along the bridge's longitudinal axis in its permanent condition.
  • May 25, 2018
    Winner: Frank Maximchuk, GeoNorth Engineering Ltd.
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    Question:
    Self-anchored suspension bridges are suited best for which of the below applications?
    Correct Answer:
    bPoor soil conditions at both cable-anchor points.
    Incorrect Answers:
    aPoor soil conditions at one cable-anchor point and good soil conditions at the other cable-anchor point.
    cWhere the girder/deck must be slender for navigational channel requirements.
    dWhere temporary falsework is not practical due to adverse weather/water currents.
  • May 11, 2018
    Winner: Stanley Chan
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    Question:
    Which girder/deck cross-section would be expected to exhibit the most favourable aerodynamic behaviour for very-long span bridges?
    Correct Answer:
    bB
    Incorrect Answers:
    aA
    cC
    dD
  • April 27, 2018
    Winner: Gregory Leonard, Pennsylvania Department of Transportation
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    Question:
    To help reduce bending stresses in the towers of the Base Case cable-stayed bridge below, which of the following solutions is likely to be least effective:
    Correct Answer:
    bB
    Incorrect Answers:
    aA
    cC
    dD
  • April 13, 2018
    Winner: Rajesh Kumar, Bridgecon
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    Question:
    Multi-span cable-stayed bridges are becoming increasingly popular. These bridges lack the back-stay support available to typical 2- and 3-span cable-stayed bridges. As a result, they can be susceptible to excessive deflections, bending moments, and stress variations. To alleviate these issues, which of the following alternatives has been implemented most frequently:
    Correct Answer:
    aA
    Incorrect Answers:
    bB
    cC
    dD
  • March 16, 2018
    Winner: Francois Leprince, CIMA+
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    Question:
    Which of the cable-stayed bridge towers below will likely experience the highest stresses due to live loads?
    Correct Answer:
    aA
    Incorrect Answers:
    bB
    cC
    dD
  • March 2, 2018
    Winner: Aman Sidhu
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    Question:
    Ship collision is important for bridges situated on major waterways carrying large ships or barges.  To protect the bridge piers, engineers can place the piers on shore, use artificial islands/dolphins and other guide structures, or simply make the piers strong enough to withstand a direct collision.  To design these latter countermeasures, the engineers need to consider a variety of ships that may be producing the impact forces.  Which of the relationships below most closely approximates the relationship between ship deadweight tonnage (traveling at a given velocity) and impact force?
    Correct Answer:
    dD
    Incorrect Answers:
    aA
    bB
    cC
  • February 16, 2018
    Winner: Alex Rutwind, UVic.
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    Question:
    For cable-stayed bridges, heavy concrete side spans can help counterbalance comparatively long main spans. Which of the bridges below does not employ this technique?
    Correct Answer:
    dThe St. Nazaire Bridge, France
    Incorrect Answers:
    aThe Atal Bridge, India
    bThe Normandy Bridge, France
    cThe Flehe Bridge, Germany
  • February 2, 2018
    Winner: Balamurali Prabhakaran, VSL India.
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    Question:
    During the construction of the Basohli Bridge the stay cables were installed strand by strand. Because this operation causes the bridge to deform, each strand is installed to a unique target force. When successfully completed all strands have equal forces. Graphs A to D show sequences of target forces for a 17-strand cable, with strand 1 installed first. Which graph shows the correct sequence of target forces?
    Correct Answer:
    dD
    Incorrect Answers:
    aA
    bB
    cC
  • January 19, 2018
    Winner: Jun Lau, UBC.
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    Question:
    When investigating flutter for long-span cable-supported steel bridges, what damping ratio for the structure is most appropriate?
    Correct Answer:
    `
    Incorrect Answers:
    a0%
    b0.5%
    c2%
    d5%
  • January 5, 2018
    Winner: John Mathens, Ramboll.
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    Question:
    Typically, for long-spanbridges, the mass of a tuned mass damper (TMD) should be in the vicinity of __ % of the oscillating mass.
    Correct Answer:
    b5%
    Incorrect Answers:
    a1%
    c20%
    d30%
  • December 15, 2017
    Winner: Monica Rotterdam, U of A Student.
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    Question:
    Considering both the maximum fatigue stress and minimum effective stiffness of the back-stay cables of a 3-span cable-stayed bridge, which of the following bridge types will likely have the lowest ratio of side span length to main span length?
    Correct Answer:
    cSteel railway bridge
    Incorrect Answers:
    aSteel road bridge
    bConcrete road bridge
    dConcrete railway bridge
  • December 1, 2017
    Winner: Liza Richardson, Student.
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    Question:
    What damping ratio is most appropriate when considering an 80-year old steel suspension bridge undergoing a 1-in-475 year seismic event?
    Correct Answer:
    a0.5%
    Incorrect Answers:
    b2%
    c5%
    d7%
  • November 17, 2017
    Winner: Tanush Sharma, Freyssinet.
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    Question:
    Suspension bridges are commonly fitted with a central clamp between the deck and the main cable to reduce longitudinal translation of the cable under asymmetrical traffic loads. Which of the following connections is most efficient in achieving this objective?
    Correct Answer:
    dd
    Incorrect Answers:
    aa
    bb
    cc
  • October 19, 2017
    Winner: Monique Levesque, McGill Student
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    Question:
    What is the primary reason most suspension bridges have an offset (Δ in the figure) between the cable and the deck at midspan?
    Correct Answer:
    aAesthetic considerations
    Incorrect Answers:
    bGreater structural efficiency under dead load
    cGreater structural efficiency under live load
    dImproved aerodynamic performance
  • October 6, 2017
    Winner: Stephen Novac, BCIT Student
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    Question:
    The Pont des Pierres or "Bridge of Stones," which stood in the French Alps from 1910 to 1944, had a masonry arch spanning 80m. It was constructed on wooden falsework rising out of the river bed. When both halves of the arch were complete, the key stone or "voussoir" was placed at the crown to complete the arch.

    Imagine that in spring, immediately after placing the voussoir, the workers leave the site due to a payment dispute. In high summer, they return to the site to find a horizontal crack in the voussoir along a hidden flaw in the stone. The master mason wants to break out the voussoir and replace it but is concerned about collapse should there be a sudden jolt as the locked in forces are relieved. Which measure would not be helpful in reducing this risk?
    Correct Answer:
    alighting fires along the top of the arch
    Incorrect Answers:
    bsoaking the wooden falsework
    cwaiting until winter
    ddriving wedges into each joint in the wooden falsework
  • September 22, 2017
    Winner: Rachael Winchester, UVIC.
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    Question:
    A three-span module of the Sultanganj Bridge is constructed by balanced cantilevering with a portion of the end spans constructed on falsework during the dry season.

    Figure 1

    After closure and removal of the falsework, the stay cables are re-stressed to improve the distribution of stresses in the superstructure.

    Figure 2

    Stay cable 14S7, 160m in length, is re-stressed at both anchorages simultaneously. Which statement about the stresses caused at points a, b, c & d in the superstructure is true?
    Correct Answer:
    ba, b are in compression; c, d are in tension
    Incorrect Answers:
    aa, b, d are in compression; c is in tension
    ca, b, d are in tension; c is in compression
    da, b, c are in tension, d is in compression
  • September 7, 2017
    Winner: Terry Styran, Crown Castle
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    Question:
    On the Arrah-Chapra bridge, all balanced cantilevers are complete and the final segment needs to be cast-in-place over the pier. Over a 24-hour duration, the cantilevers move vertically through a range of 60mm due to thermal effects. To the fresh concrete in the final segment, this movement would be extremely damaging. To prevent the movement, the contractor"s superintendent builds a falsework support on the edge of the well foundation which can resist vertical compression. At what time of day should the contractor engage the support?
    Correct Answer:
    csunrise
    Incorrect Answers:
    asunset
    bmidnight
    dmidday
  • August 25, 2017
    Winner: Mithun Mohan, International Bridge Technologies
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    Question:
    Extradosed and cable-stayed bridges with a single plane of parallel strand cables often utilize a cable saddle in their pylons. Generally, for which of the following is not an advantage of this system compared to traditional pylon anchorages for extradosed or cable-stayed bridges that utilize a single plane of parallel strand cables?
    Correct Answer:
    bSimpler cable installation process
    Incorrect Answers:
    aNarrower pylon dimensions
    cSmaller overall deck width
    dLess overall anchorage material
  • August 10, 2017
    Winner: Lucas Wise, IBT
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    Question:
    A suspension bridge is to be designed for a blast loading of 10kPa applied to the towers and superstructure. If this load were applied as an equivalent static force, it would govern the design of the towers, therefore a dynamic analysis is carried out to determine the influence of the short load duration.

    If a load is applied suddenly and sustained for a long duration, the dynamic response of the structure will exceed the response to the same load applied statically (dynamic amplification), but if the load duration is very short, the dynamic response will be less.

    If the tower has a transverse natural period of vibration of Tn = 0.60 seconds, and the loading is applied as a rectangular pulse load, what pulse load duration would produce a dynamic response equal to the response of this same load applied statically? Assume structural damping is negligible and can be ignored.?
    Correct Answer:
    atd = 0.10 seconds
    Incorrect Answers:
    btd = 0.15 seconds
    ctd = 0.30 seconds
    dtd = 0.60 seconds
    etd = 1.20 seconds
  • July 28, 2017
    Winner: Wolfgang Konn from Arcadis Consultants
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    Question:
    Which of these stiffening girders are most suitable for a cable-stayed bridge with a single cable plane?
    Correct Answer:
    cC
    Incorrect Answers:
    aA
    bB
    dD
  • July 14, 2017
    Winner: Steve Fung, Schnabel Engineering
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    Question:
    Which of these pylon configurations is most favorable in terms of aerodynamic stability?
    Correct Answer:
    aA
    Incorrect Answers:
    bB
    cC
    dD
  • June 30, 2017
    Winner: Anna Lemaire, COWI NA
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    Question:
    The low inherent damping of stay cables may require countermeasures to reduce the potential for unstable oscillations. One of these countermeasures is the use of helical fillets that are incorporated on the outside of the stay cable HDPE protective pipes. The primary purpose of the helical fillets is to prevent what type of dynamic excitation?
    Correct Answer:
    bWind-rain galloping oscillation
    Incorrect Answers:
    aIce galloping oscillation
    cWind buffeting
    dWind vortex shedding
  • June 16, 2017
    Winner: Jacob Kern from Flatiron
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    Question:
    For suspension bridges, what is typically the most economic type of pylon cross-section?
    Correct Answer:
    aHollow concrete section, e.g. on the Lillebaelt Bridge
    Incorrect Answers:
    bSteel multi-cellular section, e.g. on the Golden Gate Bridge
    cSteel box section, e.g. on the Lelu Island Bridge
    dSteel mono-cellular section, e.g. on the First Bosporus Bridge
    Question:
    Generally speaking, when does this system produce an overall less economical bridge design?
    Correct Answer:
    cIn locations with very poor soil conditions
    Incorrect Answers:
    aIn areas with high air traffic
    bIn regions with high seismic hazard
    dIn regions with high design wind speeds
  • June 1, 2017
    Winner: Brian Taylor, BC Ministry of Transportation and Infrastructure
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    Question:
    Generally, what cable arrangement theoretically requires the least amount of cable steel for cable-stayed bridges with spans between 200m and 300m?
    Correct Answer:
    bFan, e.g. the Pasco-Kennewick Bridge
    Incorrect Answers:
    aSuspension, e.g. the Lelu Island Bridge
    cHarp, e.g. the Arrah-Chhapra Bridge
    dFan-Harp, e.g. the Nipigon River Bridge
    Question:
    What is the main reason this system is not commonly used?
    Correct Answer:
    aRequires expensive anchorages
    Incorrect Answers:
    bLong construction duration
    cLess aesthetically pleasing
    dRequires specialized construction equipment
  • May 19, 2017
    Winner: Jose C Calisto da Silva, STV Inc.
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    Question:
    Over the past 10 years, what is the most common type of stay cable system?
    Correct Answer:
    dParallel strand cable, e.g. used on the Atal Setu Bridge
    Incorrect Answers:
    aFiber strand cable, e.g. used on the Storchenbrücke Bridge
    bLocked-coil cable, e.g. used on the Deh Cho Bridge
    cParallel wire cable, e.g. used on the Helgeland Bridge
    Question:
    What is the main advantage of this system?
    Correct Answer:
    cHighest tensile strength
    Incorrect Answers:
    aMost durable
    bHighest stiffness
    dLeast creep