- March 16, 2018Winner: Francois Leprince, CIMA+Show QuestionQuestion:Which of the cable-stayed bridge towers below will likely experience the highest stresses due to live loads?Correct Answer:aAIncorrect Answers:bBcCdD
- March 2, 2018Winner: Aman SidhuShow QuestionQuestion: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:dDIncorrect Answers:aAbBcC
- February 16, 2018Winner: Alex Rutwind, UVic.Show QuestionQuestion: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, FranceIncorrect Answers:aThe Atal Bridge, IndiabThe Normandy Bridge, FrancecThe Flehe Bridge, Germany
- February 2, 2018Winner: Balamurali Prabhakaran, VSL India.Show QuestionQuestion: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:dDIncorrect Answers:aAbBcC
- January 19, 2018Winner: Jun Lau, UBC.Show QuestionQuestion: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, 2018Winner: John Mathens, Ramboll.Show QuestionQuestion: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, 2017Winner: Monica Rotterdam, U of A Student.Show QuestionQuestion: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 bridgeIncorrect Answers:aSteel road bridgebConcrete road bridgedConcrete railway bridge
- December 1, 2017Winner: Liza Richardson, Student.Show QuestionQuestion: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, 2017Winner: Tanush Sharma, Freyssinet.Show QuestionQuestion: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:ddIncorrect Answers:aabbcc
- October 19, 2017Winner: Monique Levesque, McGill StudentShow QuestionQuestion: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 considerationsIncorrect Answers:bGreater structural efficiency under dead loadcGreater structural efficiency under live loaddImproved aerodynamic performance
- October 6, 2017Winner: Stephen Novac, BCIT StudentShow QuestionQuestion: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 archIncorrect Answers:bsoaking the wooden falseworkcwaiting until winterddriving wedges into each joint in the wooden falsework
- September 22, 2017Winner: Rachael Winchester, UVIC.Show QuestionQuestion: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.
After closure and removal of the falsework, the stay cables are re-stressed to improve the distribution of stresses in the superstructure.
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 tensionIncorrect Answers:aa, b, d are in compression; c is in tensionca, b, d are in tension; c is in compressionda, b, c are in tension, d is in compression
- September 7, 2017Winner: Terry Styran, Crown CastleShow QuestionQuestion: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:csunriseIncorrect Answers:asunsetbmidnightdmidday
- August 25, 2017Winner: Mithun Mohan, International Bridge TechnologiesShow QuestionQuestion: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 processIncorrect Answers:aNarrower pylon dimensionscSmaller overall deck widthdLess overall anchorage material
- August 10, 2017Winner: Lucas Wise, IBTShow QuestionQuestion: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 secondsIncorrect Answers:btd = 0.15 secondsctd = 0.30 secondsdtd = 0.60 secondsetd = 1.20 seconds
- July 28, 2017Winner: Wolfgang Konn from Arcadis ConsultantsShow QuestionQuestion:Which of these stiffening girders are most suitable for a cable-stayed bridge with a single cable plane?Correct Answer:cCIncorrect Answers:aAbBdD
- July 14, 2017Winner: Steve Fung, Schnabel EngineeringShow QuestionQuestion:Which of these pylon configurations is most favorable in terms of aerodynamic stability?Correct Answer:aAIncorrect Answers:bBcCdD
- June 30, 2017Winner: Anna Lemaire, COWI NAShow QuestionQuestion: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 oscillationIncorrect Answers:aIce galloping oscillationcWind buffetingdWind vortex shedding
- June 16, 2017Winner: Jacob Kern from FlatironShow QuestionsQuestion:For suspension bridges, what is typically the most economic type of pylon cross-section?Correct Answer:aHollow concrete section, e.g. on the Lillebaelt BridgeIncorrect Answers:bSteel multi-cellular section, e.g. on the Golden Gate BridgecSteel box section, e.g. on the Lelu Island BridgedSteel mono-cellular section, e.g. on the First Bosporus BridgeQuestion:Generally speaking, when does this system produce an overall less economical bridge design?Correct Answer:cIn locations with very poor soil conditionsIncorrect Answers:aIn areas with high air trafficbIn regions with high seismic hazarddIn regions with high design wind speeds
- June 1, 2017Winner: Brian Taylor, BC Ministry of Transportation and InfrastructureShow QuestionsQuestion: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 BridgeIncorrect Answers:aSuspension, e.g. the Lelu Island BridgecHarp, e.g. the Arrah-Chhapra BridgedFan-Harp, e.g. the Nipigon River BridgeQuestion:What is the main reason this system is not commonly used?Correct Answer:aRequires expensive anchoragesIncorrect Answers:bLong construction durationcLess aesthetically pleasingdRequires specialized construction equipment
- May 19, 2017Winner: Jose C Calisto da Silva, STV Inc.Show QuestionsQuestion: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 BridgeIncorrect Answers:aFiber strand cable, e.g. used on the Storchenbrücke BridgebLocked-coil cable, e.g. used on the Deh Cho BridgecParallel wire cable, e.g. used on the Helgeland BridgeQuestion:What is the main advantage of this system?Correct Answer:cHighest tensile strengthIncorrect Answers:aMost durablebHighest stiffnessdLeast creep