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| Street View, May 2018 |
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| Street View, Sep 2021 |
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| Thaddeus Roan Flickr, License: Creative Commons Attribution (CC BY) Keystone Wye Bridges Keystone Wye Bridges between Keystone and Rapid City, in the Black Hills of South Dakota. An interchange of US 16 and US 16A located in the Black Hills, featuring two unique "glulam" (Glue-laminated) timber bridges. The Keystone Wye is a trumpet-style three-way interchange for the two divided highways, constructed in 1966-67 as part of the project converting US 16 to a four-lane, divided highway from Rapid City, South Dakota to Keystone for visitors to Mount Rushmore National Memorial. The high bridge is supported by three 20-meter [66'] wooden, single-hinged arches; six separate glulam pieces are used in the construction. Three more pieces were built but failed quality assurance tests; they were assembled into an interesting pyramidal sculpture which for years was located just off US 16 on the then-south edge of Rapid City (a site today occupied by a motel and convenience store), and which was moved to a new location on US 16 near Sitting Bull Crystal Cave in the mid-1990s. The name Keystone Wye apparently predates the construction of the modern interchange. Major intersections in the Black Hills are frequently named, whether there are communities at the locations or not. (Wikipedia) |
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| Wood Research And Development posted Keystone Wye in South Dakota really cool bridge and interchange that features and all timber deck. Blake Scheidegger: That looks like it might not be just the deck, but structural lumber as well. Wood Research And Development: Blake Scheidegger yeah the entirety of the structure are glulam structural beams with galvanized steel design detailing the cool part was the decking was originally asphalt like most major highway bridges and interchanges but after having to replace the asphalt 3 times they switched it to leave it as a timber deck which actually improved the structural rating. |
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| atropesend 1 of 6 photos |
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| EquipmentWorld, Source: Jack Corr The arch planks are 91' (28m) long. "It would have to be done over the winter and be opened in May in time for tourist season. Because of the difficulty of pouring concrete in South Dakota’s cold climate, the DOT decided to replace the concrete decks and steel rails with wood. The DOT also liked that the wood would enhance the aesthetic appearance of the state’s famous landmark." |
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| EquipmentWorld, Source: Jack Corr To avoid damaging the wood arches, "the demolition process, which began in August, was a tedious one. Pieces of concrete structure, 10 feet by 10 feet, were removed one at a time after being saw cut. Crews drilled holes in each panel for lifting pins. An excavator then lifted the panels....The lower bridge deck, which is 50 feet below the upper deck, could be demolished by more conventional methods with hydraulic breakers." There is a thin layer of asphalt on top of the new Douglas fir deck to protect the wood. The lower bridge was strengthened by " installing high-strength fiber material bonded to a wood backer and then glued and bolted to the bottom of the beams." The project cost $4.5m. |
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| DOT_gallery, 1 of several construction photos |
Construction was finished before the tourist season of 2022. [BlackHillsFox, KOTATV]
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| DOT_complete, 1 of several photos A $2.8m project in 2023 improved the clearance of the lower bridge by lowering the road. |
Three images from South Dakota Public Broadcasting:
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| 1:00 video @ 0:36 |
A 28:03 video about the original construction I did not watch it because South Dakota's web server was so bad. The video would play just a few seconds before buffering for many seconds. I did a speed test and measured 119mbs. So the performance problem was not on my end.
Later, I tried again. Iit started OK, but after a minute it became unwatchable again.
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