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}} The Walnut Lane Bridge is a concrete arch bridge located in Northwest Philadelphia that connects the Germantown and Roxborough neighborhoods across the Wissahickon Creek in Fairmount Park.〔(Fairmont Park at AOL Local Life )〕 While drivers may cross the bridge too quickly to notice, the view from underneath the bridge has inspired many artists and writers, such as Christopher Morley.〔Morley, from "Up the Wissahickon," in Christopher Morley's Philadelphia (New York: Fordham Press, 1990) 217-218.〕 The design was copied from Pont Adolphe in Luxembourg.〔(【引用サイトリンク】title=Walnut Lane Bridge )〕 The Walnut Lane Bridge was added to the National Register of Historic Places in 1988. ==Construction== Construction began on July 5, 1906 and was completed on October 14, 1908. Over 40,000 tons of rubble concrete (containing a great amount of large stones, for greater shear strength) were poured into the falsework, which had been built from steel bents high and of timber, weighing about 900 tons.〔"Moving the Centering of the Walnut Lane Arch at Philadelphia", ''Engineering News'', Vol. 58, no. 7, p. 169, 15 August 1907.〕 The bridge's six spans total . Very little use was made of reinforcing steel, which was scarce at the time. The roadway is wide, flanked by reinforced-concrete sidewalks and pre-cast concrete balustrades.〔George S. Webster and Henry H. Quimby, "Walnut Lane Bridge, Philadelphia", ''Transactions of the American Society of Civil Engineers'', Vol. 65, no. 1128, p. 430, 1909.〕 The chief engineer was George S. Webster, assisted by Henry Quimby, both of the Philadelphia Department of Public Works. At the time of its construction, the bridge was the longest and highest concrete arch bridge in the world.〔City of Philadelphia. Annual Report of the Director of the Department of Public Works. (1908).〕 While $240,000 was originally committed to the project, the figure rose to nearly $260,000 by completion (equivalent to nearly $6 million in 2008). 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Walnut Lane Bridge」の詳細全文を読む スポンサード リンク
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