A Survey of Steel Arch Bridges in China

Sep. 2011, Volume 5, No. 9 (Serial No. 46), pp. 799-808 Journal of Civil Engineering and Architecture, ISSN 1934-7359, USA D DAVID PUBLISHING A Su...
Author: Maria Stewart
21 downloads 0 Views 191KB Size
Sep. 2011, Volume 5, No. 9 (Serial No. 46), pp. 799-808 Journal of Civil Engineering and Architecture, ISSN 1934-7359, USA

D

DAVID

PUBLISHING

A Survey of Steel Arch Bridges in China Baochun Chen1, Kangming Chen2, Shozo Nakamura2 and Qiu Zhao1 1. College of Civil Engineering, Fuzhou University, Fuzhou, Fujian 350108, China 2. College of Civil and Environmental Engineering, Nagasaki University, Nagasaki 852-8521, Japan Abstract: A review of the current status and progress of steel arch bridges in China is presented in this paper. The existing steel arch bridges in China were analyzed in terms of steel material, span, structure type, main arch rib form and construction method. The comparison with CFST arch bridges and RC arch bridges is also conducted. It is shown that steel arch bridge has gain rapid development in China since 2000, characterized by long main spans. As for the span, most of the steel arch bridges have a span less than 250 m, while when the span exceeds 350 m, steel arch bridges are strongly competitive against CFST or RC arch bridges. Over 80% of the bridges are through and half-through bridge types, and the arch ribs are hingeless structures. The rise-to-span ratios of the arches are mainly between 1:4 and 1:5. Most of the arches use solid box ribs, and a small portion of arches use truss ribs in which box sections are mostly adopted for the truss members. The cantilever method and scaffolding method are the two main construction methods used, but some other construction methods have also been developed. Key words: Steel arch bridge, survey, bridge type, rib, construction method, China.

1. Introduction  Arch bridge has a long history in China. The arch is aesthetically beautiful, highly stiff, and can be in multiple structural forms, hence has become one of the main bridge types in China, even when there are so many bridge types available in the recent 30 years of Large-Scale Infrastructure Construction period, when a large number of bridges are built. Moreover, lots of world-class achievement has been witnessed in the field of bridge design and construction. All the span records of arch bridges with respects to construction materials are all held in China, i.e., the New Danhe Bridge in Shanxi Province with a main span of 146 m (Stone arch bridge), the Wanxian Yangze River Bridge in Sichuan Province with a main span of 420 m (RC arch bridge), the Wuxia Yangze River Bridge in Sichuan Province with a main span of 460 m (CFST arch bridge), and the Chaotianmen Bridge in Chongqing with a main span of 552 m (steel arch bridge), respectively [1]. Almost all arch bridge construction methods used in other countries have been Corresponding author: Baochun Chen, professor, research fields: bridge engineering. E-mail: [email protected].

adopted in China, such as the scaffolding method, cantilever method, swing method and embedded scaffolding method. Some of them are specifically used in China, such as the horizontal swing method, embedded CFST scaffolding method and cantilever hoisting with long span and large tonnage by cable cranes [2]. Very few steel arch bridges had been built before 2000 in China, while more and more steel arch bridges have been built later on, some of them have very long spans. Considering its short history, more research and practice is necessary on design and construction of steel arch bridges. In this context, a few domestic and foreign experts and scholars in this field have been invited by the first author to jointly compile the book of Steel Arch Bridge to introduce the design and construction methods for steel arch bridges in the USA, Europe, Japan, and China. In this process, a large amount of data and literature have been collected, and as a by product, those steel arch bridges in China collected before July of 2010, spanning not less than 100 m, are analyzed in this paper in terms of steel material, span, structural type and construction method.

800

A Survey of Steel Arch Bridges in China

With the rise of labor cost, the ever dominant, time-consuming stone arch bridges are no longer in favor of in China today. Instead, steel arch bridge, CFST arch bridge and concrete arch bridge have been happily accepted in recent decades. Similar reviewing works have been done and reported, respectively, in References number 3 and 4 for CFST arch bridges (before March, 2005) and RC arch bridges (before August, 2007) spanning no less than 100 m. They are expanded by including bridges built in recent years, and compared with those of steel arch bridges hereby.

2. Evolution of Steel Arch Bridges The evolution of arch bridge is closely related to construction materials. The industrialization of iron and steel enabled their initial use in arch bridges, the main long span bridge type at that time. The world’s first cast iron bridge was constructed in England (the Ironbridge, completed in 1779). Some wrought iron bridges were also built during this period, such as the well-known Garabit Bridge in Massif with a main span of 165 m (completed in 1884) and the Maria Pia Bridge in Portugal with a main span of 160 m (completed in 1877). Steel arch bridge was firstly established in the USA (Eads Bridge, completed in 1874). Its success promoted the booming development of steel arch bridges worldwide. A number of steel bridges were built successively, such as the Hell Gate Bridge built in the USA in 1916 with a main span of 298 m, the Sydney Harbor Bridge constructed in Australia in 1932 with a main span of 503 m, the Bayonne Bridge and New River Gorge Bridge with main spans of 504 m and 518.3 m in the USA [5]. The appearance of steel bridges in China is much late. The Dahong Bridge in Tianjin may be the first one. It was firstly a wooden bridge and reconstructed into a steel arch bridge in 1887, which was swept away by flood in 1924. Reconstruction of the New Dahong Bridge was planed again in 1933, and completed in 1937. It is a through steel arch bridge with three spans;

the main span is 57.37 m. The bridge is still in use now [6]. For a long period of time in China, scarcity of material and backwardness of industrialization forbad a large number of steel bridges from being built. Steel were only used in key bridges crossing major rivers. When the Wuhan Yangtze River Bridge was being built in 1950s, the construction steel was imported from the former Soviet Union. Afterwards, it was possible to produce the type 16Mn steel to build the Nanjing Yangtze River Bridge in 1970s. However, this kind of steel experienced significant size effect so that its strength and ductility reduced quickly with the increase of thickness. A new type of steel, 15MnVNq steel with the yield strength of 420 MPa, was developed and used in the Baihe Bridge in 1976. But the poor weldability prevented it from further use except the Jiujiang Bridge in 1992. It was really embarrassing that no steel other than the 16Mn could be used in bridge engineering at that time [7]. Very few steel highway bridges had been built before 1990s. The No. 2 & 3 Panzhihua Bridges were two representatives at early time. The former is a steel box arch bridge with a main span of 180 m, completed in 1966. The later is a steel truss arch bridge with a main span of 180 m, completed in 1969. Surely, the 16Mn steel was the only choice [8]. As a result of the Economic Reform and Opening Up from 1978, steel industry in China has developed quickly and now is the top producer in the world. There are rich types of steel products available now. At present, steel bridges mainly adopt the Q345q and the Q370q types in China, and more and more bridges use the Q420q steel, and a tendency of using high-performance steel. Therefore, more and more steel bridges have been constructed in the latest three decades of the Large-Scale Infrastructure Construction. The steel arch bridges started to popup after many long span steel cable-stayed bridges and steel suspension bridges being built.

801

A Survey of Steel Arch Bridges in China

In 2003, a long span steel arch bridge, the Lupu Bridge in Shanghai, was built. The complete of this bridge renewed the world record of steel arch span by then. The bridge is a half-through steel tied bridge with three arches, the main arch spans 550 m with a rise-to-span ratio of 1:5.5, and the other two side arches span 100 m each. The bridge was constructed of the normalized structural steel S355N in accordance with the German industrial standard DIN10113-1993 for weldable fine-grained steel [9]. Later on, several long span steel arch bridges were built successively, such as the Xinguang Bridge with a main span of 428 m in Guanzhou (steel truss arch

bridge, 2007), the Caiyuanba Yangtze River Bridge with a main span of 420 m in Chongqing (steel box arch bridge, 2007), the Chaotianmen Bridge with the world’s longest main span of 552 in Chongqing (steel truss arch bridge, 2007), the Daninghe Bridge with a main span of 400 m in Chongqing (steel truss arch bridge, 2010), and so on. A good number of steel arch bridges and their details have been obtained from surveying and literature review. However, in order to save space, only 27 of steel arch bridges with main spans no less than 150 m are listed briefly in Table 1.

Table 1 Long span steel arch bridges in China (main span ≥ 150 m). Order

Bridge Name

Main Span (m)

Type

Completed Year

1

Zhujiang Baishahe Bridge in Guangzhou

150

Half through

2008

2

Kanjing Bridge in Taiwan

150

Though

2002

3

Jingde Bridge inTaiwan

155

Though

2001

4

Guandu Bridge in Taiwan

165

Half through

1983

5

Jilonghe Bridge

166

Double deck

N/A

6

No.1 Mengshuai Bridge in Taiwan

170

Double deck

2001

7

Yaojiang Bridge in Ningbo (aka Wantou bridge)

180

Through

2009

8

No.2 Panzhihua Bridge(aka Dukou Bridge)

180

Deck

1966

9

No.3 Panzhihua Bridge (aka Midi Bridge)

181

Deck

1969

10

Baling Bridge in Taiwan

185

Half through

2005

11

Min River Bridge located in Fuxia railway

198

Half through

2009

12

Zhongzhaiwan Bridge in Xiamen

208

Half through

2004

13

Jiubao Bridge in Hangzhou

210

Through

2011

14

No.2 Mengshuai Bridge in Taiwan

210

Through

1996

15

Jiujiang Yantze River Bridge

216

Double deck

1992

16

Rongjiang Railway Bridge in Shantou

220

Half through

Under construction

17

Dongpingshuidao Railway Bridge in Guangdong

242

Half through

2009

18

Nanning Bridge in Guangxi

300

Half through

2009

19

Dongping Bridge in Foshan

300

Half through

2006

20

Dashengguan Yangtze River Bridge in Nanjing

336

Half through

2009

21

Wangzhou Yangtze River Railway Bridge in Chongqing

360

Half through

2005

22

Daninghe Bridge in Chongqing

400

Deck

2010

23

Caiyuanba Yangtze River Bridge in Chongqing

420

Half through

2007

24

Xinguang Bridge in Guangzhou

428

Half through

2006

25

Mingzhou Bridge in Ningbo

450

Half through

2011

26

Lupu Bridge in Shanghai

550

Half through

2003

27

Chaotianmen Bridge in Chongqing

552

Half through

2007

802

A Survey of Steel Arch Bridges in China

3. Distribution of Quantity and Main Span

2015

2010

2005

2000

1995

1990

1985

1980

1975

1970

1965

Under Construction

600 Chaotianmen Bridge 550 Lupu Bridge 500 450 Xinguan Bridge Caiyuanba Bridge 400 350 300 Jiujiang Yangtze 250 River Bridge 200 Dukou Bridge Guandu Bridge Midi Bridge 150 100 Yingsuihe Bridge 50 0 1960

Main Span/m

A total of 65 steel arch bridges were collected in this paper, with 52 bridges’ main span no less than 100 m, and 46 bridges’ completed year known or under construction. Fig. 1 shows the main spans and completed years of steel arch bridges, with a few representative bridges labelled. Fig. 2 is the histogram of span distribution (including steel arch bridges in Taiwan). It can be seen from Fig. 1 that the distribution of steel arch bridge in China can be partitioned roughly into two stages by the year of 2000. From 1966, the year of the first steel arch bridge completed, to 2000, only 8 bridges (17.4%) were built in this duration of

Completation Era

Quantity of Steel Arch Bridge

Fig. 1 Main spans and complete years of steel arch bridges

30 27 24 21 18 15 12 9 6 3 0

100-149 Before 2000 After 2000

150-199 200-249 300-349 400-449 ≥450 350-399

Main Span/m Fig. 2

Histogram of span distribution.

35 years. The one with the longest main span, 216 m long, is the Jiujiang Yangtze River Bridge, which is a combination of steel truss girder and steel arches. Compared with foreign steel arch bridges and those RC and CFST arch bridges in China, the construction of steel arch bridges in China is obviously lagged behind. In the decade after 2000, 38 bridges with main spans of 100 m or longer were built, which accounted for 82.6% of total. Most long span bridges were built in this period, the average main span is 216 m. As mentioned above, the Lupu Bridge completed in 2003 renewed the world span record to 550 m, which was soon broken by the 552 m span in Chaotianmen Bridge in 2007. We can see from Fig. 2, the main spans of 26 bridges (nearly half) in list are between 100 m and 149 m, 10 bridges (19.2%) between 150 m and 199 m, 6 bridges (11.5%) between 200 m and 249 m, 3 bridges each in the ranges of 300 m-349 m, 400-449 and 450 m or longer, only 1 bridge between 350 m and 399 m. None of the bridges spans between 250 m and 299 m. In summary, the main span of steel arch bridge in China are mostly below 250 m, say 42 out of 52 (80.7%). Apart from steel arch bridge, RC arch bridge and CFST arch bridge have also gained rapid progress in China. Combined by the data from Refs. 3-4 and the investigation of the arch bridges in China in recent years in this paper, there are 180 CFST arch bridges and 203 RC arch bridges with main spans over 100 m by July, 2010. Figs. 3 and Fig. 4 compare the advances of these three categories of arch bridges. As shown in Fig. 3, the number of RC bridges has been increasing since 1965, most significantly between 1985 and 1998, and slowed down later on. The number of CFST bridges increases most quickly at an average speed of more than 10 bridges per year during recent two decades. Steel arch bridge seemed to lag much behind until 2000, and then the development accelerated, although the quantity of steel arch bridge is still fewer than of the other two.

A Survey of Steel Arch Bridges in China

180 160 140

Quantity

120

Steel Arch Bridge CFST Arch Bridge RC Arch Bridge

100 80 60 40 20 0 1960

1970

1980

1990

2000

Completation Era

2010

Main Span/m

Fig. 3 Comparison of three types of arch bridges by quantity.

600 550 500 450 400 350 300 250 200 150 100 1960

Steel Arch Bridge CFST Arch Bridge RC Arch Bridge

1970

1980

1990

2000

2010

Completion Era Fig. 4 Comparison of three types of arch bridges by main span.

Fig. 4 shows the span development histogram of the three arch bridge types. For RC arch bridge, the Jingdu Bridge completed in 1965 is the first one with a main span over 100 m. The next year, the main span of No. 7 Bridge crossing the Beijing Yongding River reached 150 m. During the 23 years from 1966 to 1989, marked by the completed of Wujian Bridge, the span of RC bridge increased only 50 m, due to the backward construction technology and shortage of construction materials. In contrast, the Sibenik Bridge and the Pag Bridge with main spans of 246.4 m and 193.2 m had been built in the former Yugoslavia (now Croatia) as early as 1966 and 1967. Moreover, the No. 1 and 2 KrK Bridges with long spans of 390 m and 244 m were built in 1979. In the mean time, many short span RC arch bridges at low

803

level of technology were constructed before 1990 in China. Things changes after 1990s, the technology for RC bridges stepped into a fast growing period. The Wanxian Bridge, as a representative of RC bridges, completed in 1997 became the world record-holder of main span, which is 420 m, increasing the span record by 220 m in 8 years. After 1997, this trend slowed down. In recent years, there are several RC railway arch bridges with main spans longer than 400 m in construction, which will definitely promote technological progress of RC arch bridge in China. Meanwhile, in order to improve the spanning capability of RC arch bridges, researches on applying new materials and structural forms are under way, such as the using of reactive powder concrete and RC box arch with corrugated steel webs [10], plane steel webs or steel truss webs [11-13]. One of the aims of these studies is to reduce self-weight effectively so as to improve the spanning ability of RC arch bridge. The application time of CFST arch bridges in China is relatively short; however the increase of span is quick. The Wushan Yangtze River Bridge located in the Reservoir of the Three Gorges, completed in March, 2005, has a main span of 460 m [9]. A new CFST arch bridge under construction has a main span of 530 m in Sichuan Province. It is expectable that the upper limit of the span of CFST arch bridge is far from being reached. So does steel arch bridge. Theoretically, with current construction technology and material, the span limit of steel arch bridge can be 1200 m [7]. Fig. 5 compares the quantity and main span distribution of three types of arch bridges. As can be seen from the figure, the majority of the main spans of all three types of arch bridges are between 100 m and 200 m. In this range, the number of RC bridges is the largest one, while the number of the steel bridges is the smallest one. When the main span is between 200 m and 349 m, CFST arch bridges are mostly used, while the other two are almost the same. In the span range of 350~499 m, there are 5 each of steel and CFST bridges,

Quantity

804

A Survey of Steel Arch Bridges in China

200 180 160 140 120 100 80 60 40 20 0

Steel Arch Bridge CFST Arch Bridge RC Arch Bridge

100-199

200-349

350-499

500 or more

Main Span/m Fig. 5 Distribution of quantity and main span of three types arch bridges.

but only 1 RC bridge. There are still no RC and CFST arch bridges exceeding 500 m span, except steel arch bridges. Previous comparison indicates that RC arch bridge is the most competitive when the main span is shorter than 200 m, but steel arch bridge and CFST arch bridge take over when the span is between 350~500 m, steel arch bridge dominates when the span exceeds 500 m.

4. Structure Type 4.1 Overall Structural Forms There are many forms of steel arch bridges. With respect to the articulation of main arch, they can be classified into four categories, i.e., three-hinged, two-hinged, single-hinged and hingeless (or, fixed) steel arch bridges. For single-hinged and three-hinged arch bridges, the existence of hinge in the middle of arch might increase the tendency of damage at heavy impact loads. And the maintenance of the hinge in the middle is much difficult. Therefore, there are very few three-hinged arch bridges worldwide, none in China. The two-hinged and fixed steel arch bridges are frequently used in foreign countries, and the two-hinged form was mainly adopted at early times. Most of the steel arch bridges in China were built in the last decade; therefore, most of them are fixed. With respect to the relative position of the bridge deck and the arch rib, steel arch bridges can be

categorized into deck, half-through, through and double-deck steel arch bridges. In the 45 steel arch bridges with structure types known, there are 3 (6.7%) deck bridges, 28 (60.0%) half-through bridges, 12 (26.6%) through bridges, and 3 (6.7%) double-deck bridges, respectively. The deck steel arch bridge consists of arch rib and spandrel structure. It is ideal for crossing a valley with sound rock walls. In order to match the lightweight but strong characteristics of the arch, the spandrel structure of steel arch bridge is usually constructed by steel, together with steel-concrete composite decking system. Generally speaking, steel deck arch bridge requires a large amount of steel which make it uneconomic compared to RC arch bridges and CFST arch bridge if the site condition and time permitting. Therefore, there exist only a few deck type steel arch bridges in China. Steel arch bridge is advantageous in light self-weight compared with RC arch bridge, consequently, many through and half-through steel arch bridge have been constructed in plain area, as stated above, they account for 88.9% of the total, in which most of them are half-though bridges. The same is the CFST arch bridges, in which only 8% are deck type, while 82% are through and half-through [4]. However, more than half of RC arch bridges are of deck type and only a small part are through and half-through bridges [3]. There is no doubt that arch bridge is a beautiful, functional, understandable and expressive structural form. The lightweight but strong characteristics of steel arch coincide with architect’s vision on structural forms, so that lots of forms have been designed in the world. However, these bridges are usually constructed as light loaded road bridges or pedestrian bridges. In recent years, the trend to pursue aesthetic feeling of steel arch bridges is also appeared in China. The main gymnastics are done by: (1) Reversing the vertical or inner-inclined ribs to outer-inclined, balanced by leaning or hangers; (2) Spatial composition of arch ribs of various scales; (3) Deformed arch axial line. If the appearance and

A Survey of Steel Arch Bridges in China

aesthetics of a bridge are presumably very important and the increased costs are limited and acceptable, variant arches may be considered. But they should not be used excessively, or for long spans or for heavily loaded bridges, because the likely result would be very expensive but not exactly beautiful bridges. 4.2 Main Span Rise-to-Span Ratio

Quantity of steel arch bridge

Rise-to-span ratio is an important parameter of steel arch bridge. The distribution of rise-to-span ratios used in existing steel arch bridges in China is illustrated in Fig. 6. Fig. 6 shows that the rise-to-span ratios of steel arch bridges in China are in the range of 1:2 to 1:8, mostly between 1:4 and 1:5, other ratio values (beyond 1:2 and 1:8) are usually employed in short span steel arch bridges. In addition, as shown in Fig. 7, there is no direct correlation between the rise-to-span ratio and the span. 12 1/4-1/5

10 8 1/4

6 4

1/5-1/6

1/2-1/3

2

1/5

1/6 1/6-1/8

1/2

1/8

0

Rise to span ratio Fig. 6 Rise-to-span ratios of steel arch bridges in China.

805

In China, the commonly employed rise-to-span ratios of RC arch bridges are between 1:5 and 1:8, mostly 1:6. While the commonly employed rise-to-span ratios of CFST arch bridges are between 1:4 and 1:5, mostly 1:5 [3, 4]. By comparison, the rise-to-span ratio of steel arch bridge is slightly greater. For parabolic arches, the relationship between steel volume and f/l and g/p has been derived by variation method in Reference 14, as given in Fig. 8, where g and p are dead load and live load acting on the arch rib, and f/l is the rise-to-span ratio. Fig. 8 shows that it is most material saving when the f/l varies in the range of 1/5-1/6. In addition, the ratio of g/p has significant influence on the amount of steel used. The rationality of rise-to-span ratios commonly used in China still requires further study and practice. 4.3 Arch Axes For maximizing the compressive resistance of arch rib, the arch axis is expected to close to the compression line of dead load. Among the selected 52 bridges in this paper, the arch axes of 24 bridges, except unknown or specific shape bridges, are shown in Table 2. It can be seen from Table 2 that: parabolas are adopted in 14 steel arch bridges, account for 58.3% of the total; catenaries are used in 6, or 25%; other curves are only 4 or 16.7%. It is obvious that the parabola is the most popular arch axis in steel arch bridges because

Rise to span ratio

1/2

1/3 1/4 1/5 1/6 1/7 1/8

0

100

200

300

400

500

600

Main span / m Fig. 7 Relationship between rise-to-span ratio and main span length.

Fig. 8 Relationship between steel volume and rise-to-span ratio.

806

A Survey of Steel Arch Bridges in China

Table 2 Arch axes of steel arch bridges.

Arch axial line

Quantity of bridges

Parabola

14

Percentage (%) 58.3

Catenary

6

25.0

Other

4

16.7

of the approximately uniform distribution of its dead loads. However, catenary axes are mostly used for RC arch bridges, especially for the deck bridges with heavy spandrel columns, characterized by continuously increasing of self-weight load density from the crown to the springing [3]. For CFST arch bridges, catenary and parabola axial lines are almost equally commonly used [4]. 4.4 Section of Arch Rib The sections of arch ribs can be classified into solid type and truss type. All the 39 bridges with section types known are selected for analysis here. Solid ribs are used in 25 (or 64.1%) of them and truss ribs are used in the rest 14 (35.9%), which means solid ribs are mainly adopted in steel arch bridges in China. The solid rib is usually adopted in short steel arch bridges, its section can be I- or H-shaped, circular tube or box-shaped. The I-shaped and circular tube sections are used in a few small span steel arch bridges in some countries, but never used in China. The box shape is the main section of steel arch bridges in China. Meanwhile, some unfamiliar box sections such as octagon shape (the No. 1 Bridge crossing the Chanba River in Xian) and oval shape (the Yangtze River Bridge in Zhongsan and the Liuwu Bridge in Lasa) are occasionally used. And for some long span bridges, a single box section with double cells are used, such as the Lupu Bridge in Shanghai with a main span of 550 m and the Mingzhou Bridge in Ningbo with a main span of 450 m. Truss ribs can be more effective and are preferred when the arch span exceeds 200 m. Members in truss ribs are smaller and lighter than those in solid section ribs; therefore, they facilitate delivery and erection. However, the truss ribs are more difficult to fabricate for their connection and the complexity sometimes

affect the beauty. Because steel arch bridges have larger stiffness than those of cable-stayed bridges and suspension bridges, they have been used in many high-speed railway bridges which need very rigid structures. The sections employed in solid ribs may also be used in truss members of steel arches, such as I- or H-shaped, circular tube and box section. However, box section members are mostly used in China for its great stiffness and simple configuration in long span steel arch bridges. Other section members are rarely used.

5. Construction Method Similar to the construction methods used for RC and CFST arch bridges, the scaffolding method, the cantilever method and the swing method are also used for steel arch bridges. In addition, the lightweight and high stiffness of steel arch bridge enable using of launching method and hoisting method for the whole superstructure or large segments of the structure. The known construction methods used in selected steel arch bridges are shown in Table 3, and the relationship between construction method and main span is illustrated in Fig. 9. Table 3 shows that quite many (41.9%) steel arch bridges are constructed using the scaffolding method. When the river is shallow with little navigation, scaffolding method is appropriate. This method is also used for railway steel bridge of flexible arch and rigid

Scaffolding Method Cantilever Method Other Method 100

200

300

400

500

600

Main Span / m Fig. 9 span.

Relationship between construction method and

A Survey of Steel Arch Bridges in China Table 3 Construction methods for steel arch bridges.

Cantilever method

Quantity bridges 14

Scaffolding method

13

41.9

Swing method

2

6.5

Launching method

1

3.2

Cable hoisting method

1

3.2

Construction method

of

Percentage (%) 45.2

girder, in which the arch ribs are erected through scaffolds on the rigid girder previously constructed. About 45.2% of the steel arch bridges were constructed using the cantilever method. This method can be used in long span bridges. Besides the cable-stayed cantilever method which also mostly used for RC and CFST arch bridges, the free cantilever method can also be used in steel arch bridge construction. The cable-stayed cantilever method requires complicated temporary structures such as pylons, cables and anchoring, whose design and construction are sometimes much more challenging and difficult than the bridge itself. The free cantilever method is the favourable choice for a steel truss arch rib because the rib has a great stiffness and load-carrying capacity; therefore the need for auxiliary structures is minimized. This method was adopted in the construction of the Dashengguan Bridge closed in August 2009. Each of the side arches was erected using the free cantilever method via a short pylon and a pair of cables. The two central arches were erected via horizontal cables in three levels anchored back to back to each other. The deck truss was installed synchronously with the arch ribs. The scaffolding method and the cantilever method are obviously main construction methods for 87.1% of the selected steel arch bridges. They are also widely used in the construction of RC arch bridges (82.5%) and CFST arch bridges (79.4%) [2-4]. The swing method is specially used for arch bridges in China. About 8.4% of RC arch bridges, 14.6% of CFST arch bridges, and 6.5% of steel arch bridges are constructed using this method.

807

The hoisting method was used in the construction of the Xinguang Bridge in Guanghzou. The arch rib was hoisted and assembled from three large segments, the heaviest one weighted 2850 t. The launching method was used for the Jiubao Bridge in Hangzhou. Although other methods are rarely adopted, however owing to the lightweight and high stiffness of steel arch rib, it is possible to develop better construction methods to promote technological progress in construction.

6. Last Remarks A comprehensive survey on steel arch bridges with respect to history, steel material, main span, structural form and construction method has been reported in this paper. Statistical comparison of steel arch bridge to RC bridge and CFST arch bridge is also briefly addressed. Steel arch bridges are used relatively late and still in small scale today in China. However, rapid progress has been made in recent years. This development has improved steel arch bridge engineering technologies in the fields of design, fabrication and erection. Steel arch bridges remain popular structure types that are frequently adopted for modern bridges even though designers now have many more structural types to choose from. Many steel arch bridges will be built for their elegant appearance and favored by designers and owners for highway and city roads. At the same time, this bridge type is strongly competitive in long span, high-speed railway bridges with a high requirement of stiffness. Therefore, steel arch bridge still has prosperous future in this era of large scale transportation infrastructure construction in China. The survey of steel arch bridges in China in this paper is expected to provide a base data and reference for its future research and construction.

Acknowledgments The authors would like to thank Dr. Xinmeng Yu for his valuable comments and English revision for this paper.

808

A Survey of Steel Arch Bridges in China

References [1]

[2]

[3]

[4]

[5]

[6]

[7]

B. C. Chen, Long span arch bridges in China, in: Proceedings of Chinese-Croatian Joint Colloquium on Long Span Arch Bridges, Brijuni Islands, Croatia, July 10-14, 2008, pp. 119-134. B. C. Chen, Construction methods of arch bridges in China, Construction of Arch Bridges, in: Proceedings of the 2nd Chinese-Croatian Joint Colloquium on Long Span Arch Bridges, Fuzhou, China, October 5-9, 2009, pp. 1-186. B. C. Chen and Y. Lin, An overview of long span concrete arch bridges in China, in: Proceedings of Chinese-Croatian Joint Colloquium on Long Span Arch Bridges, Brijuni Islands, Croatia, July 10-14, 2008, pp. 163-170. B. C. Chen and T. L. Wang, Overview of concrete filled steel tube arch bridges in China, in: Practice Periodical on Structural Design and Construction, ASCE, May 2009, pp. 70-80. K. J. Wright and M. A. Brunner, Arch bridges, in: R. L. Brockenbrough and F. S. Merritt,Structural, Steel Designer’s Handbook (4th ed.), McGraw-Hill, 2006. H. F. Xiang, X. H. Fan and S. C. Zhang, The History of China Bridges, Shanghai, Tongji University Press, 2009. (in Chinese) B. L. Chen, The development of the welded bridges in China, Journal of Electric Welding Mechanic 37 (3) (2007) 1-5. (in Chinese)

[8]

[9]

[10]

[11]

[12]

[13]

[14]

Department of Transportation Highway Bureau, Highway Bridge Album of China, Beijing, China Communication Press, 1978. (in Chinese) G. P. Yue, Key technology for design of Lupu Bridge, in: Proceedings of Chinese-Croatian Joint Colloquium on Long Span Arch Bridges, Brijuni Islands, Croatia, July 10-14, 2008, pp. 431-438. R. Y. Du, J. Yu and B. C. Chen, Trial design of a reactive powder concrete (RPC) arch bridge with a span of 420 m, in: Proceedings of 6th International Conference on Arch Bridges, Fuzhou, China, Oct. 2010, pp. 126-132. J. G. Wei, Q. W. Huang and B. C. Chen, Trial design of arch bridge of composite box section with steel web-concrete flange, Frontiers of Architecture and Civil Engineering in China 4 (3) (2010) 370-375. J. G. Wei, Y. Feng, B. C. Chen and Q. X. Wu, Tests of a composite box arch having steel truss web and concrete flange under unsymmetrical in-plane loads, in: Proceedings of 6th International Conference on Arch Bridges, Fuzhou, China, Oct. 2010, pp. 611-615. B. C. Chen and T. M. Mou, Research on concrete arches with steel webs, in: Proceedings of Chinese-Croatian Joint Colloquium on Long Span Arch Bridges, Brijuni Islands, Croatia, July 10-14, 2008, pp. 189-196. Yichirou Conishi, Steel Bridges, Maruzen Co. Ltd., Tokyo, Japan, 1975. (in Japanese)

Suggest Documents