Questions in this quiz: Modern Architectural Marvels

Contemporary engineering icons. Burj Khalifa, Shanghai Tower, Sydney Opera House, Guggenheim Bilbao, CN Tower, the Channel Tunnel, the Millau Viaduct, the Akashi Kaikyō Bridge.

1. The Akashi Kaikyō Bridge held the record for the world's longest main span of any suspension bridge for over two decades. By how much was its planned span famously extended during construction? — Options: It grew about 1 metre due to thermal expansion during summer welding, It grew about 1 metre due to the 1995 Kobe earthquake shifting the towers, It was shortened about 1 metre due to a typhoon-induced cable adjustment, It grew about 1 metre after engineers recalculated tidal loading
2. Which structural feature is the Shanghai Tower most associated with as an engineering innovation for supertall buildings? — Options: A 120-degree twisting facade that reduces wind loads by roughly a quarter, A diagrid exoskeleton eliminating the need for an internal core, A base-isolated foundation floating on rubber bearings, A buttressed-core plan derived from a three-pointed Y shape
3. The Channel Tunnel actually comprises three parallel bores. What is the function of the smaller central tube? — Options: A high-voltage power and telecoms conduit, A service tunnel for ventilation, maintenance, and emergency evacuation, A dedicated freight-only single-track line, A drainage gallery that pumps seepage back to the surface
4. What is the Millau Viaduct's most distinguishing structural-form claim? — Options: It is the longest concrete arch bridge in the world, It has the tallest bridge piers in the world, It is the longest single-span suspension bridge in Europe, It is the world's first bridge built entirely from prefabricated stainless steel
5. The CN Tower's main observation pod is supported by a hollow hexagonal concrete shaft. Which technique was central to building that shaft so rapidly in the early 1970s? — Options: Continuous slipforming, with the formwork rising about 6 metres per day, Precast concrete ring segments lifted by a tower crane, Steel-plate composite construction filled with self-compacting concrete, Jump-form construction in 12-metre lifts cured under heat blankets
6. Jørn Utzon's original 1957 competition entry for the Sydney Opera House did not specify how its iconic shells would actually be built. What geometric breakthrough finally made their construction feasible? — Options: Treating each shell as a hyperbolic paraboloid, Cutting all shells from the surface of a single sphere, Approximating each shell with triangulated geodesic panels, Defining the shells as ruled surfaces of revolution about a central axis
7. Frank Gehry's Guggenheim Bilbao is clad mostly in a metal not previously used at architectural scale on a major building. Which metal — and why was it chosen? — Options: Anodised aluminium, for its corrosion resistance in the maritime climate, Stainless steel, for its mirror-like reflectivity, Titanium, partly because a Russian oversupply made it briefly affordable, Zinc, for its self-healing patina in rainy conditions