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When this photograph was taken sometime before 1928, the Zhaozhou Bridge had been altered somewhat and there was sufficient water in the stream for vessels with sails to pass.
Although built more than 1,400 years ago, the Zhaozhou Bridge in Hebei appears like a contemporary bridge because of its low line and open spandrels.
Following the pattern of the Zhaozhou, also called Anji (Safe Passage) and Dashi (Great Stone), Bridge, no fewer than four were built in nearby areas of Hebei province where natural conditions were similar, while at least twenty others were constructed in northern China as well as in Guizhou and Guangxi. Until the middle of the twentieth century, the Zhaozhou Bridge was the longest single-arch span bridge in China. The restoration of the Zhaozhou to its original form and the building of similar bridges in recent times confirm that the Chinese recognize their early achievements in engineering technique and aesthetic expression. A masterpiece built almost 1,400 years ago, the Zhaozhou Bridge foreshadowed the elegance and scale of many contemporary bridges. In terms of economy of materials and aesthetic qualities, it is clearly the direct ancestor of the relatively light and lithe modern reinforced concrete bridges that dispense with stonework between the curvature of the arch and the flat deck above. As discussed on pages 123–7, the circumstances surrounding the construction of the Zhaozhou Bridge reveal the conscious attention to natural conditions, transportation requirements, and available materials, in addition to inspired creativity.
As with the Zhaozhou Bridge, each of the double sets of openings that pierce the arch spandrel on both ends of the smaller Yongtong (Eternal Crossing) Bridge reduces the weight of the structure and eases the flow-through of water during flood.
Multiple Arch Bridges
Multiple arch bridges are widely found in China, compelling evidence of both the diffusion of designs throughout the empire and the innovative skills of local bridge builders. Surprisingly monumental structures in what are today backward villages stand as a testament to the vitality of road and river transport in centuries past, the same commercial energy that gave rise to the magnificent mansions of merchants and gentry in out-of-the-way places. As with multiple-span beam bridges, arches were linked together to bridge greater distances than was possible with a single arch. Almost always an odd number, ranging from as few as three to as many as seventy, the duplication of spans almost always invokes pleasing rhythm with its repeating elements. Arch bridges with three spans are especially common in Jiangsu and Zhejiang provinces in a region of a dense canal network. Soft alluvial soils in this low-lying region meant that bridges had to be relatively light. In addition, it was necessary for the bridges to rise rather high so as not to obstruct the passage of canal boats, many of which were powered by sails attached to tall masts. Unlike in the north, land transport of goods rarely involved carts or animals but depended upon individuals carrying shoulder poles who were capable of mounting steps as long as they could maintain their gait. Today, cyclists must dismount as they approach a steep bridge, but it is not difficult to push even a loaded bicycle up one of the ramps that have been added to the steps in recent times. Triple-arch bridges typically have a large central span, approximately 20 percent longer than the pair of identical smaller side arches. The two piers of such bridges are usually relatively thin given the spans they support, the load of adjacent arches being carried by the shared piers. Even though some triple-span bridges appear frail, insufficiently massive to carry the load of the arch shell, balustrades, and walkway, they are capable of substantial loads. Although only a small number of five-, seven-, and nine-span stone arch bridges survive, they differ little in structure from more modest three-span bridges, with loads being passed from one arch ring to another until reaching the abutments.
Records indicate that the longest multi-span thin-pier stone arch bridge, which crossed an arm of Taihu Lake just outside the city wall of Wujiang in Jiangsu province, was constructed in 1325 during the Yuan dynasty to replace a shorter wooden span on stone piers that had been built in 1066 and subsequently modified several times. Although called the Chuihong (Hanging Rainbow) Bridge, the structure did not soar. Instead, it was built only slightly elevated above the water except for several triple-arch segments that rose to facilitate the passage of vessels beneath. Until 1967 and the collapse of many sections, it stood as China’s longest multiple arch bridge at 450 meters with 72 spans. Only 49.3 meters and ten arches remain on the east end of the original bridge, today protected within a park. Restoration efforts continue to dredge up fallen arches, which then are added to the original span. Few Chinese bridges have received the accolades from poets and painters as has the Chuihong Bridge.
The 140-meter-long Ziyang (Purple Sun) Bridge in Shexian county, Anhui, is said to have been built during the reign of Wanli (1572–1620) in the Ming dynasty, but the bridge seen today was completed in 1835. Given its length and width, the bridge is a remarkably light structure, with eight stone piers and nine arches.
The Renji (Benevolent Aid) Bridge, completed during the Ming dynasty and rebuilt after a flood in 1868 with contributions from local folk, is 79 meters long and supported by four stone piers. With the equally old Pingzheng (Peaceful Governance) Bridge in the background, the pair is considered a place for townspeople to welcome the new moon. Qimen county, Anhui.
Close-up of the bow-shaped cutwaters of the 89-meter-long Pingzheng Bridge in Qimen county, Anhui. Records show the construction of bridges at this site during both the Song and Ming dynasties. After being destroyed in a disastrous flood in 1830, it was not until the nineteenth century that it was rebuilt. In 1974, the bridge was strengthened and widened.
Built first in the early ninth century, the Baodai (Precious Belt) Bridge is actually an elegant towpath extending 317 meters along the Grand Canal, which took its current form during the Ming dynasty. In addition to lengthy abutments that jut out from the shore, fifty-three arches cross open water for 250 meters.
Squeezed between modern structures, this triple-arch span is just one of many remarkable bridges in Jinze, a watertown now swallowed up in the suburbs of Shanghai.
No currently standing multiple arch bridge is longer than the Baodai (Precious Belt) Bridge, which spans 317 meters, with fifty low arches and three mid-span higher arches that permit boat traffic. As a low-lying bridge with thin stone piers, its appearance is said to resemble the jade belt donated by the governor who financed its construction. Built first in the early ninth century during the Tang dynasty, it took its current form about 1446 in the Ming dynasty. Adjacent to a broad section of the Grand Canal some 7 kilometers southeast of Suzhou, the replicated arches of the Baodai Bridge span the Dantai River as it empties into the Grand Canal. It was constructed as a link in a towpath which otherwise would have been broken because of the confluence of the two water bodies. The bridge was rebuilt in 1872 after a major collapse during the Taiping Rebellion, a subject discussed on ages 198–9, and restored in 1956. Once regularly visited to enjoy its technical achievements, today few seek out the bridge because of its remoteness, except during the Mid-Autumn Festival when the stone pavement affords a commodious space to view the full moon.
Accompanying a vocalist,
