Chinese Bridges. Ronald G. Knapp. Читать онлайн. Newlib. NEWLIB.NET

Автор: Ronald G. Knapp
Издательство: Ingram
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Жанр произведения: Техническая литература
Год издания: 0
isbn: 9781462905867
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hand, the underlying lifting structure is comprised of three sets of timber chords.

      Said to have been built in the Tang dynasty, the Wo (Reclining or Holding) Bridge in Lanzhou, Gansu, served as a river crossing on the Silk Road. This mid-twentieth century photograph shows the bridge as it was restored in 1904, long before it became the prototype model for the Baling Bridge in Weiyuan.

      Taken at the end of the nineteenth century, this covered bridge has an open pavilion atop it.Weizhou, Sichuan.

      Long timbers laid horizontally on the stone abutments provide support for this modest covered bridge in the Sichuan countryside, which was photographed at the end of the nineteenth century.

      Structurally a cantilevered timber bridge rather than a woven timber arch bridge, the Baling Bridge in Gansu is regarded as a “rainbow bridge.”

      The Buchan (Stepping Toad) Bridge in Qingyuan county, Zhejiang, was first built between 1403 and 1424 and then rebuilt in 1917. Its single stone arch has a diameter of 17.8 meters while the corridor bridge itself has a length of 51.6 meters. Fifty meters away from the bridge is a stone in the water that is said to resemble the fabled toad in the moon, which led to the belief that one could reach the moon by crossing this bridge.

      The Yingjie Temple Bridge in Jushui township, Qingyuan county, Zhejiang, is adjacent to a temple built during the Song dynasty, rebuilt in 1662, and then restored in 1850 to its current state.

      Modest covered bridges like this one in Fujian are found throughout southern China, where they provide not only easy passage over a stream but also offer a place for farmers and travelers to rest.

      The 15.1-meter-long Sanzhu (Three Posts) Bridge, Zhejiang, has a clear span of 10.1 meters. The horizontal logs that support the timber frame corridor are held up by three stone pillars sunk into the streambed.

      Good examples of covered bridges of many types are found throughout southern Zhejiang and northern Fujian provinces. Taishun and Qingyuan counties in mountainous Zhejiang share characteristics with the neighboring Fujian counties of Pingnan, Shouning, Zhouning, Gutian, Fu’an, and Fuding, each of which has a large number of striking covered bridges.

      Only three stone columns hold up the timber assemblage supporting the Sanzhu Bridge, a relatively short covered bridge, 15.4 meters long, in Xia Wuyang village in Taishun. Also in Taishun is the 36-meter-long two-storey Yongqing Bridge, whose structure includes a piled cantilever timber beam bridge set upon a single midstream pier. Just upstream of the Yongqing Bridge, one can still see the chiseled-out indentations in the rocky bottom of the stream into which a set of pillars once supported a precursor bridge. Although its origins are unknown—it was last restored in 1916—the covered corridor of the Buchan Bridge in Qingyuan county was constructed over a massive single stone arch. Built above a smaller stone arch, the Yuwen Bridge is sited well among old trees and a rambling stream. A path paved with smooth stones drops from the adjacent hillsides, suggesting that the bridge is an anchor site in a system of mountain–valley byways. The imposing set of altars on the upper level of the bridge affirms its centrality in village worship. The Yingjie Temple Bridge in Qingyuan county is adjacent to one of the oldest extant temples in the region, which was built during the Song dynasty and then rebuilt in 1662. Also a two-storied bridge structure, the Yingjie Temple Bridge spans a narrow stream atop a series of long, parallel logs. Richly ornamented inside, the bridge continue as a vital community center. Among the most outstanding covered bridges in Shouning is the Luanfeng Bridge in Xiadang township. Built first in 1800 and restored in 1964, the bridge has a clear span of 37.6 meters, the greatest of any timber bridge in China, and an overall length of 47.6 meters and width of 4.9 meters. Among other notable covered bridges are the Yongqing Bridge, Liuzhai Bridge, and Dongguan Bridge, each with its own local characteristics.

      In terms of internal building structure, only a relatively small number of covered bridges utilize masonry walls for the enclosed structure, an example of which can be seen on pages 208–11. As in dwellings and temples throughout China, the pillars-and-transverse-tie beams wooden framework, called chuandou in Chinese, and the column-and-beam construction, the tailiang framing system, are used in constructing bridges. Both of these wooden framework systems directly lift the roof. The pillars-and-transverse-tie beams wooden framework is common throughout southern China, and has been utilized in the Buchan, Yuwen, and Luanfeng bridges. This framing system is characterized by pillars of a relatively small diameter, with each of the slender pillars set on a stone base and notched at the top to directly support a longitudinal roof purlin. Horizontal tie beam members, called chuanfang, are mortised directly into or tenoned through the pillars in order to inhibit skewing of what would otherwise be a relatively flexible frame. Wooden components, as will be seen in many photographs, are linked together by mortise-and-tenoned joinery, practices that can be traced back 7,000 years to Neolithic sites in eastern China. Column-and-beam construction involves a stacking of larger building parts: a horizontal beam, large in diameter and often curved, with two squat queen posts, or struts, set symmetrically upon it, followed by another beam and a culminating short post. Bracket sets are frequently used to extend the eaves substantially beyond the walls of the bridge. The Yingjie Temple Bridge utilizes the tailiang framing system, with heavier and more substantial columns as well as large horizontal beams.

      Built in 1797, the Yongqing (Eternal Celebration) Bridge in Taishun county, Zhejiang, is a cantilevered bridge with piled timbers laid atop its single midstream pier. With a length of 36 meters, the bridge rises 5.2 meters above the streambed.

      Timber frameworks of this type create a kind of “osseous” structure analogous to the human skeleton, which allows great flexibility, including structures that rise and fall as well as those comprising multiple levels. Because many covered bridges in China are also the sites of a shrine or temple, the roof structures are often more elaborate than those found on homes and are more like the roofs of temples. Ceiling structures are quite varied, especially near shrines and altars, where elaborately carved and painted coffered forms are common. With sawn timber cladding, the walling on bridges is generally simpler than that found on dwellings and temples.

      Placed in a repeating fashion, sets of pillars and beams support the roof of the Yongqing Bridge.

      Midway across the corridor, a set of wooden steps leads to the loft containing a variety of deities on several altars.

      Much like the practices adopted in building houses, units of the wooden framework are assembled on the ground before being raised to a perpendicular location, where they are then propped and secured to adjacent segments by longitudinal cross members. As with Chinese house building, the raising of the ridgepole as well as some of the columns are important steps that are accompanied with ritual. With shrines and altars, covered bridges are transformed into active sites of worship, a subject discussed and illustrated on pages 72–5.

      Garden Bridges

      While the term “garden” in the West brings with it the notion of a relatively diminutive space with landscaped