The Republic of China period, i.e., from 1912 to 1949, roughly corresponds to the first half of the 20th century.

        Shanghai is the city in China where pile foundations were applied earliest and most extensively. The achievements of pile foundation engineering in Shanghai attracted international attention as early as 1936 at the First International Conference on Soil Mechanics and Foundation Engineering held at Harvard University, USA, and the paper “Records of Some Pile Tests in Shanghai” (Faber S.E.) was included in the conference proceedings, see Proceedings of the First ICSMFE, 1936, Vol. I, I-3, pp. 194-199.

        As is well known, steel and cement are products of the Western Industrial Revolution, which later gave rise to concrete and reinforced concrete. In 1890, the first cement products factory appeared in Shanghai, using cement imported from the UK as raw material, initially producing drainage pipes, bathtubs, and water tanks. By the early 20th century, the factory introduced British production technology and began producing reinforced concrete poles and precast reinforced concrete piles. At the same time, foreign construction units used British-made Vibro piling equipment to install concrete driven cast-in-place piles, called “Vibro piles”. Thus Shanghai entered a new era of using three types of piles simultaneously: traditional timber piles (predominant), precast reinforced concrete piles, and cast-in-place piles. This was a historic breakthrough in pile foundation application in China.

        From the late Qing Dynasty and early Republic of China, roughly until the 1930s, the application of timber piles in Shanghai had the following characteristics:
① Even for buildings of three or four stories, timber piles were often used if there was doubt about the strength of the foundation. They were generally a few meters long, with a maximum length not exceeding 15 m; the butt diameter was about Φ300 mm and the tip diameter about Φ150 mm.
② When building residential buildings, timber piles were often driven at the four corners of the building plan, because it was believed that the foundation stress at the corners was higher and should be reinforced.
③ Some buildings had timber piles driven under the eccentric wall foundation along the property line for safety.
④ In multi-story and high-rise buildings and heavy structures, due to larger superstructure loads and improved piling equipment, timber piles up to 30 m long began to be used, with correspondingly larger diameters.
⑤ Short timber piles (Fujian logs, also called Jiansong) were often used to treat weak foundations such as hidden ponds.


      Mr. Yu Diaomei, a pioneer in pile foundation engineering research in China, recorded in his monograph “Foundation Engineering in Shanghai” (Tongji University Press, 1991) that when the Shanghai Henan Road Bridge was built in 1923, its five pier foundations used square timber piles of four different lengths (3.7~15.2 m) and different cross-sections (36×36, 30×30, and 30×10 cm), which fully demonstrates the ingenuity of our predecessors in bridge building and pile use, see Fig. 1.

         Completed in 1923, the N.C.D. News Building (formerly known as Zilin Xibao Building) was China's first modern high-rise building, 40.2 m high, with 8 stories in the main body and 11 stories including basement and mezzanine, with a floor area of 9043 m2. It was built on a timber pile foundation. The building was renamed Guilin Building in 1951 and then AIG Building in 1998, and has been in use for over 90 years. See Fig. 2. The famous Shanghai Jinjiang Hotel, whose North Building was originally called Huamao Apartments (see Fig. 3a), was first built in 1929, 57 m high, 13 stories, on a timber pile foundation. Due to soft ground and poor design, and because the contractor cut corners during pile construction by sawing the timber piles into two sections and driving only the butt section into the ground, the building continued to settle after completion until it stabilized at -2.6 m. However, no severe differential settlement occurred, so steps were built at the entrance leading directly to the second floor as a lobby, and the original first floor became a basement.

In 1931, the owner of Huamao Apartments built the Junling Apartments, now the South Building of Jinjiang Hotel (see Fig. 3b), to the south. It consists of three connected parts: the central main building is 18 stories high, and the east and west parts gradually step back from the 13th floor.

In February 1972, then US President Nixon made his “ice-breaking” visit to China. After meeting Chairman Mao in Beijing, he visited Shanghai accompanied by Premier Zhou Enlai and stayed at the South Building of Jinjiang Hotel. On February 28, 1972, President Nixon and Premier Zhou jointly signed the “Shanghai Communiqué” in the small auditorium of Jinjiang Hotel.

The famous Broadway Mansions (now “Shanghai Mansions”) by the Waibaidu Bridge in Shanghai, see Fig. 4, was built in 1930, 19 stories plus one basement, supported on timber piles 24.4~36.6 m long and φ325 “Franki” piles. Later the building tilted to the southeast, presumably because some timber piles were cut corners during construction.

During the pile driving for the Broadway Mansions foundation, the pier of the Waibaidu Bridge 40 m away was displaced, causing the bridge truss to separate and necessitating repairs. This was the first major case in China's engineering community where the environmental impact of pile driving was experienced. The Shanghai Tilanqiao Hospital, built in 1930, is a 7-story reinforced concrete frame structure supported on timber piles of diameter Φ310 mm × length 12.2 m. The Shanghai Cade Apartments (now Huanghe Apartments, on today's Huanghe Road), built in 1931, is a 9-story reinforced concrete frame structure supported on timber piles of diameter Φ280 mm × length 18.3 m.

Built in 1934, the Shanghai Park Hotel, which was the tallest building in China before the founding of New China, is 83.8 m high, with 2 basement levels and 22 above-ground levels, commonly called “24 stories”. It is the tallest building in Chinese history supported on timber piles, see Fig. 5.
The Shanghai Railway Bureau Building (later called Railway Bureau Building No. 1) was first built in 1936, with a 10-story central part and 6-story wings, using Oregon pine round timber piles with butt diameter 360-380 mm, tip diameter 180-230 mm, and pile length 27-28 m. To prevent decay of timber piles at locations where the groundwater level fluctuates, the upper section (about 4.7 m) of some piles was encased in reinforced concrete of diameter 680 mm. In 1987, two stories were added to both the central part and the wings on the original foundation, adding 3468 m2 of floor area, 40% of the original 18553 m2. See Fig. 6.

Table 1 shows the pile types and technical parameters used in Shanghai in the 1920s and 1930s, compiled by Mr. Yu Diaomei from extensive historical literature.
Related links:
　　In Pile Anecdotes and Stories Parts 5 and 5 (sic), the stories about Shanghai Peace Hotel, Bank of China, and Qiantang River Bridge and Mr. Mao Yisheng all belong to the application of piles during the Republic of China period.