Cheong Gye Cheon Restoration in Seoul, Korea Project Description • Demolition of covering and elevated structures: 5.4 km (3.4 miles) • formation of new watercourse and river bed: 5.7 km (3.5 miles) • water supply: 120,000 m3 (1,006,370 bbl)/day through a 10.9 km (6.8 miles) long pipeline • construction of bridges: 22 • landscaping: 5.8 km (3.6 miles)
design Precedents | Oct. 13, 2010 | SeungYen Hong
Before and After
Three Themed Restoration Sections & Water Supply Pipeline
SEOUL
History & Tradition
CGC CBD
Culture & Modernity
Nature & Future
Han River
History • A century ago it was called ‘valley of clean water’ • 50s-60s: Urbanization and industrial development polluted the creek • 1967-76: The elevated highway was built to meet a demand of transportation for heavily industrialized city center • 80s: Due to economic decline of the central areas, the highway became unneccesary and concerns about air pollution, a health risk form unsanitary conditions, a decreasing stability of ageing structures increased • 90s: A group of academics and environmentalists developed a community-based master plan • 2002: Seoul Metropolitan Government launched an organization to move peoject forward
• To maintain an average depth of 0.4 m and average current velocity of 0.25 m/s, a daily supply of 120,000 m3 (1,006,370 bbl) is provided • The water supply consists of 100,000m3 (838,641bbl) extracted from the Han River,15 km away, and 20,000 m3 (167,728bbl) of groundwater
Cross-Section
The original width of the stream was kept but the bed was lowered
(65.6-371ft)
• The twin combined sewer boxes in each bank help prevent raw sewage and contaminated initial storm run-off from overflowing into the river during storms (26-236ft)
Timeline
Final Construction Costs Cost: $ milllion 346 3.6 44.4 77.3 60 21.4 84 46.9 8.4
• Clay mats and grout cut-off walls were used in the upstream section to limit water loss and scour
Removing the Freeway, Restoring the River
design Precedents | Oct. 13, 2010 | SeungYen Hong
Historic Restoration
Landscape Design & Restoration of Ecology
• Restoration of the old Gwang-Tong bridge • Ancient pillars which are remnants of the which had been buried under the covering former highway that occupied the space highway structure for four decades • The sloping embankment walls have been clad in granite to resemble a historic masonry wall.
• Small squares, works of art and waterfront decks have been provided
• The northern side of the river provides a promenade for people and the southern terrace is primarily for plants and wildlife