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LONG SPAN REINFORCED CONCRETE
ARCH BRIDGES IN YUNNAN, CHINA
Song-Ping BAI*, Jian-ping ZHOU** & Bao-Chun CHEN***
*Science and Education Division, Yunnan Communications Department
Kunming, 650093, China
**The Transport Consultation Co. Ltd in Yunnan
Kunming, 650031, China
***College of Civil Engineering, Fuzhou University,
Fuzhou, 351018, China
Key words: Yunnan, reinforced concrete, long-span, arch bridge, Songyuan-jinsha river
bridge
Abstract: Yunnan Province, an upland mountain area, lies in southwest of China. In this
region, high mountains with steep slope near rapid flow are carved up by many deep
valleys with a generally high seismic intensity. Arch Bridge can be a competitive bridge
type benefiting from its good anti-seismic capacity. Moreover, it can decrease the
substructure engineering quantity and harmonic to the surrounding. In this paper, bridges
with spans more than 100m in Yunnan Province are introduced. The construction and
technology innovation are issued by taking Songyuan Jingsha River Bridge as an example.
Constructing technology for long span arch bridge is explored to adapt to the road plane
curve.
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Bai, Zhou & Chen: LONG SPAN REINFORCED CONCRETE ARCH BRIDGES IN YUNNAN, CHINA
1. INTRODUCTION
Yunnan Province with an altitude mountain area of 94%, lies in southwest of China,
attached to the southern part of Tibet altiplano. The elevation gap between the main
mountain is very large. The highest point is 6740m in the Kawugobo Mountain and the
lowest is 76.4m in the junction of Nanxi River and Yuan river, the elevation difference
between them is 6663.6m with a horizontal distance only 900 km. There are six water
systems distributed over the Yunnan Province, Llovade River, Lu River, Lancang River,
Jinsha River, Red River and Zhu River.
In Yunnan, various perilously peaks and torrential rivers give you indelible impression,
what’s more, Yunnan bridges will give you more surprise memory naturally. Generally,
Yunnan bridges hold following characteristics: long history, wonderful, splendid and
ingenious accomplishment. Yunan bridges are called “living fossil” in ancient bridge
history because almost every bridge type used in ancient China can be found here.
Ingenuity always is included by engineers in the bridge design generation by generation and
construction originality is also considered by old and young craftsman，for example,
bamboo bridge and corridor bridge avoiding rain and wind, cantilever timber beam bridge,
cantilever stone beam bridge, persimmon flowers-shaped stone arch bridge. These bridges
are memorized in the history books for their special bridge structures and ingenious
craftwork. Recent and modern times Yunnan’s road and bridge builders succeeded
traditional technology and craftwork, referred to the experience and science and technology
achievement in and out of China, gave full scope to creativity, designed and constructed
many new fashion bridges, most of which are arch bridges. Following the technology
progress, the span of arch bridges is growing.
2. LONG SPAN ARCH BRIDGE IN YUNNAN
Long Rainbow Bridge over Nanpan River with a 112.54m long main span was constructed
in 1961 (Figure 1). It took the lead in constructing stone arch bridge in China. As the first
one stone arch bridge with a span over 100m, it is considered as the sign that the stone arch
design and construction technology stepping into a high level. The famous bridge set an
important milestone in the development of the stone arch bridge after Zhaozhou Bridge in
China.
As an open spandrel stone arch bridge, Long Rainbow Bridge was constructed on full
framing. Because of its light structure, graceful outline shape corresponding with the
surroundings and the traditional Chinese unique beauty, such as a rainbow across the river,
the bridge was called Long Rainbow Bridge. It made full use of abundance stone material
in Yunnan, getting material locally to reduce the constructing cost. Based on the former
experience on stone arch bridge, many technological innovations had been made on the
constructing and design of this kind bridge. These progresses include that using gradual
various arch rings to decrease the cross-section area of it with the purpose of saving the
material; applying segmental masonry and cyclic masonry to relieve the load acted on the
arch centering.
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Bai, Zhou & Chen: LONG SPAN REINFORCED CONCRETE ARCH BRIDGES IN YUNNAN, CHINA
Figure 1 : Long Rainbow Bridge in Kaiyuan
As development of materials and bridge construction method, reinforced concrete material
played a tremendous role in the construction and development of arch bridge whose force
behavior is mainly pressure. To reinforced concrete box-arch bridge, the main arch ring are
composed of segmental prefabricating arch rib, hoisted by cable crane, then assembled in
vertical and horizontal two directions to form a closed section, in this way, good
performance can be attained to resist compression, bending and torsion load and bypassing
capacity for arch-type bridge is greatly enhanced. Adopting this construction method,
Hongqi Bridge over Lu River with a 116m long span was built in 1974; it is the longest
reinforced concrete box-arch bridge in china at that time.
In recent years, accompanying the rapid development of highway construction, bridge
construction in Yunnan has made great progress and development. The advances for long
span arch bridge have been made in terms of the number of bridges, structure fashion,
materials, construction technology. For example, a concrete-filled steel tubular (CFST) arch
bridge like a flying bird (Figure 2), a steel box lift-basket arch bridge (Figure 3), CFST
skeleton arch bridge have been built in Yunnan Province.
Figure 2: Haikou Bridge on Gaohai highway Figure 3: Xiaowan power station Bridge
Table 1 lists the arch bridges with a span larger than 100m, it can be concluded as follows.
① Among these arch bridges, deck arch bridges are popular than half-though arch
bridges, and the latter is in the minority in the aspect of bridge fashion.
② As to the material, most of them are constructed in reinforced concrete, a few new
bridges is build with new material, such as CFST.
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Bai, Zhou & Chen: LONG SPAN REINFORCED CONCRETE ARCH BRIDGES IN YUNNAN, CHINA
Main Rise-
No. Bridge name span to Structure type Time
(m) -span
1 Long rainbow Bridge 112.54 1/6 Deck stone arch 1961
2 Hongqi Bridge 116 1/8 RC box deck arch 1974
3 Jin’an Bridge 110 1/6 RC box deck arch 1982
4 Hutiaoshi Bridge 110 1/6 RC box deck arch 1989
5 Fulong Bridge 110 1/8 RC box deck arch 1992
6 Bifu Bridge 130 1/8 RC box deck arch 1992
7 Nationality village Bridge 130 1/8 RC box deck arch 1994
8 Laochangtian reservoir Bridge 130 1/8 RC box deck arch 1994
9 Songyuan jinsha river Bridge 170 1/8 RC box deck arch 1996
10 Cikai Bridge 130 1/8 RC box deck arch 1997
11 Qingshui River Bridge 150 1/5 RC box deck arch 1997
12 Bada River Bridge 150 1/5 RC box deck arch 1997
13 Heng River Bridge 130 1/8 RC box deck arch 1997
14 Yangwu Bridge 130 1/8 RC box deck arch 1998
15 Huapichong Bridge 180 1/8 Concrete deck arch 1998
Dachao mountain power station
16 130 1/8 RC box deck arch 1998
Bridge
17 Beimiao reservoir Bridge 130 1/8 RC box deck arch 2000
18 Tantou Bridge 100 1/6 RC box deck arch 2000
19 Xiangshui river Bridge 130 1/8 RC box deck arch 2002
Half-through steel
20 Xiaowan Bridge 130 1/3.2 2002
arch
21 Jinsha river Bridge 150 1/6 RC box deck arch 2002
22 K257+872 130 1/8 RC box deck arch 2002
23 K291+959 130 1/8 RC box deck arch 2002
24 Dasheng valley Bridge 100 1/8 RC box deck arch 2003
25 Shudijinsha river Bridge 120 1/8 RC box deck arch 2003
26 Changtian reservoir Bridge 138 1/8 RC box deck arch 2004
CFST half-through
27 Haikou Bridge 150 1/4.5 2007
arch
28 Yezechong Bridge 130 1/8 RC box deck arch 2008
Table 1: Long span arch bridge in Yunnan (larger than 100m)
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Bai, Zhou & Chen: LONG SPAN REINFORCED CONCRETE ARCH BRIDGES IN YUNNAN, CHINA
③ With respect to rise-span ratio, 0.125 is applied for most bridges that belong to long
span and flat arch bridges.
④ As to the arch box, the number of open box transverse cross-section is equal to that of
closed box one. The bridge type selection mainly is restricted with the maximum hoisted
weight in the stage of construction.
⑤ Almost all of the reinforced concrete box arch bridges adopt non-supporting frame
assembly method in the aspect of elevating technology.
⑥ From reinforced concrete box arch bridge constructed sequence, almost all bridges
employed the method that prefabricated box arch ribs section, hoisted with cable cranes,
assembling a closed section in vertical and horizontal two directions to form the arch ring.
⑦ In general, the main span length of long span bridges is between 100 to 150m, rarely
exceeding 150m.
The Songyuan Jinsha River Bridge is the longest span reinforced concrete box arch bridge
in Yuannan. The bridge is built on a poor soil foundation with high earthquake intensity,
what’s more, it stand a test of an earthquake with a magnitude of 8.0 Ms in 1996 when the
bridge was under construction.
3. SONGYUAN JINSHA RIVER BRIDGE
3.1 Design Introduction
Songyuan Jinsha River Bridge (Figure 4), crosses over Jinsha River at the location of
K187+113.60 on the Xiaguan to Zhongdian highway in Yunnan Province. The bridge was
designed by Yunnan Provincial Highway Survey and Design Institute, was constructed in
the hand of Yunnan bridge engineering department. This engineering started on December
25, 1993 and accomplished on October 25, 1996. The design load for this bridge was
Vehicle-20 and Trailer-120, its deck clearance width is 7m wide lane and double 1.5m
sidewalk; and design flood frequency followed that extraordinary flood appeared one time
during the 100 years’ service life, besides 8 degree earthquake intensity.
Figure 4: Songyuan Jinsha River Bridge
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Bai, Zhou & Chen: LONG SPAN REINFORCED CONCRETE ARCH BRIDGES IN YUNNAN, CHINA
The total length of Songyuan Jinsha River Bridge is 264.81m with 170m long main span,
and the net rise to span is 0.125, a constant section catenary reinforced concrete box arch
bridge. As a long span arch bridge, the vault segment on filled spandrel were excavated to
hollow to adjust the excessive internal force from the temperature change，in this way,
hidden hollows were designed on the filled spandrel. To reduce the temperature difference,
vent holes were assigned along the bridge axis on the cross wall near the arch back. At the
same time, taking into account constructing convenience, the cross walls concrete would be
prefabricated.
Ten prefabricated T-beam were set for 6 openings on each side of the main arch, compared
with the double hinges arch bridge equipped with π plate beams, the former was lighter,
facilitated structure and saved the material. Negative longitudinal slope was equal to one
percent assigned from the vault to the bridge head on the deck to work with the connecting
road on both banks. Radius of the vertical curve at the vault was 4000m with 40m tangent
length and 0.2m tangent distance. The heights of column on the spandrel arch and cross
wall were the control point to the adjustment for longitudinal slope of the bridge deck
pavement.
As high earthquake intensity, the engineers gave full consideration to the anti-seismic
performance of structure during the design process, so that necessary anti-seismic design
was made and available anti-seismic measures were took.
To make bridge tidy, beautiful and simplify construction, approach spans used the same
arrangement as spandrel arch span. Because the bridge is located over the Jinsha River,
which water flow rapidly with a deep river bed, and the banks closed up steep mountain
slope. So the ends of approach bridges are planed in horizontal curve. In order to facilitate
the construction, the sidewalk was overhung instead of T-beams widen to go with changes
in plane curve. Of course, all abutments also were widened in the form of high parabola
corresponding with the changing road width.
In view of the leading line of cap on the Zhongdian shore close to the line of low water and
the poor geological condition, half apron walls in the front of cap were set to prevent the
abutment from being washed, ensuring that bridge was safe. For the first spandrel column
and portion pier of approach were under the design water level, cross slabs were designed
to the bent frame under the design level to avoid frames being hooked by floater in Jinsha
River. At the same time, stiffening steel bars were used in the first segment of arch rib to
resist the floating wood collision in the river.
The bridge foundation soil geological situation was listed as follow: the deposit gravel,
mixed with a little boulder, laid along river channel in Zhongdian bank; clay was mingled
with gravel in the Lijiang bank, distributing cementation marlite locally.
Therefore, according to the foundation, abutment was designed to composite one, including
the group piles with cap in the front and anti-sliding body in the behind. What’s more, 3m
thick cross wall was erected on the cap and a U-shaped abutment was put on the body to
add the friction in order to resist the horizontal force from the main arch ring.
The actual primary materials consumption of the full-bridge (including the 1.09km long
approach): 403t steel, 6075t cement, 800m3 wood (logs, lumber), 17,000m3 concrete and
7000 m3 stone masonry work. Full-bridge construction drawing budget was 17.928 million
RMB.
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Bai, Zhou & Chen: LONG SPAN REINFORCED CONCRETE ARCH BRIDGES IN YUNNAN, CHINA
3.2 Construction Introduction
The Bridge used the method of hoisting prefabricated segments that were cable-stayed and
cantilever assembled. Main arch has been made of five rooms, which is 2.6m high, 8.86m
wide. Arch ring is made of C40 reinforced concrete. U-shaped arch rib must be
prefabricated firstly, and it was 2.4m high, divided into seven parts. The maximum hoisting
weight of a single segment is 59.6 tons.
The arch rib of Songyuan Jinsha River Bridge started to be hoisted in December 30th, 1995,
and finished in February 2, 1996.
During its construction, a 7 Ms degree earthquake occurred in Lijiang, Yunnan at 19:20 on
February 3, 1996. The distance between the bridge and the epicenter is only over 20 km.
When the earthquake occurred, workers were welding the joints of arch rib. Arch box had a
severe shock, which displacement from top to bottom had reached 50 cm. The next day
after the earthquake, February 4, field observation and survey showed that:
① No transverse displacement appeared in arch ribs.
② Except slight elevation decline at the points of vault 3L/8，no significantly change at
the points of L/8, L/4.
③ During the arch rib installation process, big force made a small crack in the joints.
When the earthquake occurred, the crack length increased, the biggest increasing is 5cm.
④ After careful examination and analysis, relevant departments agreed that the arch rib
installation of Song Yuan Bridge is successful. Structure of arch box, offsetting and
elevation and other index are normal after the earthquake. Songyuan Jinsha River Bridge
followed the 8 degree anti-seismic design, had experienced an intensively earthquake test.
The bridge folded with single U-shaped rib (base rib). Design longitudinal stability factor
of single U-shaped rib: K＝5.025>[K]＝4 and transverse stability factor K＝0.948＜[K]＝
4. Data analysis showed that transverse stability factor of single rib was less than 1.0.Under
this circumstance, engineers suggested that anti-wind cables should be used to assure
transverse stability of arch rib. So 6 double cables were fixed to full arch and angle between
cable and arch axis is less than 30 degrees. Only after all five U-shaped box ribs had been
folded and adjusted in place, longitudinal connecting steel bars and joints had been welded
and cross slab had been prefabricated, these cables could be removed finally.
However, it was only 25 kilometers from the bridge to the Hutiao Gorge in lower reaches.
Taking into account the impact of wind, engineers still felt that the security can not be
guaranteed when base rib makes closure. After consulting with the construction unit, we
installed base rib like pagoda. So two springing segments were installed on both sides of
the mid segment, and then middle rib was fold. In this way the free length of arch rib
shorten to enhance the stability. What’s more, during construction the construction unit
bravely tried and succeeded to use single additional rib to achieve the closure. Then the
hoisting task was successful completed. All this experience deserved to be used in the
similar engineering in the future.
In order to make full use of lifting equipment and speed up the construction progress, main
arch rib, column of spandrel arch, spandrel columns, bent beam, T beams, slabs for hidden
holes were precasted firstly and then installed. It is good for facilitate the construction,
saved construction time and improve project quality.
After traffic test to the bridge for years, good service effect has been received and all kinds
of targets satisfy the design requirements.
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Bai, Zhou & Chen: LONG SPAN REINFORCED CONCRETE ARCH BRIDGES IN YUNNAN, CHINA
4. RESEARCH ON LONG SPAN ARCH BEIGE TECHNOLOGY
ADAPTING TO THE PLANE CURVE
As the constraints of terrain environment, highway alignment and engineering investment,
In Yunnan plateau mountain road often have the following characteristics: small plane
radius, frequently changes to longitudinal slope and long decline highway, difficult cross-
section layout. So small plane radius and steep longitudinal slope has brought great
difficulties to long span arch bridge and restricted its development. For this reason, experts
in Yunnan have to research this item named "large radius curve arch structure over v-
shaped mountains valleys in plateau". Now the main achievements are following:
① According to the characteristics of v-shaped valleys in plateau, we conducted a study
to deck arch bridge that can adapt to the large curve radius with linear, constant height,
changing width single box that composed of three rooms, then we get an available
numerical value range for plane curve radius under certain circumstances.
② According to the systematic research and analysis to the reinforced concrete box arch
bridge between 80m and 150m long, we hold out a reasonable cantilever length and
corresponding formula on the deck system for the arch bridges in different radius.
③ The comprehensive research on the three aspects, structural analysis and theoretical
calculation indicators and the alignment adaptability, is an important guiding significance
to the long span arch bridge construction that can adapt to changes in the plane radius.
5. CONCLUSIONS
There are few great rivers in Yunnan province, and highway alignment changes frequently,
so long span arch bridge construction is subject to certain constraints. However, Yunnan is
a area with excessive and intensively earthquake, according to the record of recent
earthquakes these years in Yunnan, such as Tonghai earthquake, Genma earthquake and
Lijiang earthquake, LinEr earthquake, the arch bridge has good anti-seismic performance.
At the same time, arch bridge often is the reasonable structure type in v-shaped mountain
valley. Arch bridge can utilize sufficient materials and make full use of them, moreover,
Yunnan people accumulate and summarize almost perfect design and construction
experience, specially the technology of non-supporting frame hoisting arch box. It should
be said that arch bridge construction experience is enriched and technology has been mature.
In recent years, long span arch bridge technology has been researched for adapting to the
plane curve .It can be foreseen, with the growing development of highway construction,
long span arch bridge will make a further development.
REFERENCES
[1] Yao Ling-sen. 1985. Bridge Engineering, People’s Communications Press: Beijing.
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